Visualizing the invisible: The effect of asymptomatic transmission on the outbreak dynamics of COVID-19

Abstract: Understanding the outbreak dynamics of the COVID-19 pandemic has important implications for successful containment and mitigation strategies. Recent studies suggest that the population prevalence of SARS-CoV-2 antibodies, a proxy for the number of asymptomatic cases, could be an order of magnitude larger than expected from the number of reported symptomatic cases. Knowing the precise prevalence and contagiousness of asymptomatic transmission is critical to estimate the overall dimension and pandemic potential of COVID-19. However, at this stage, the effect of the asymptomatic population, its size, and its outbreak dynamics remain largely unknown. Here we use reported symptomatic case data in conjunction with antibody seroprevalence studies, a mathematical epidemiology model, and a Bayesian framework to infer the epidemiological characteristics of COVID-19. Our model learns, in real time, the time-varying contact rate of the outbreak, and projects the temporal evolution and credible intervals of the effective reproduction number and the symptomatic, asymptomatic, and recovered populations. Our study reveals that the outbreak dynamics of COVID-19 are sensitive to three parameters: the effective reproduction number, the ratio between the symptomatic and asymptomatic populations, and the infectious periods of both groups. For three distinct locations, Santa Clara County (CA, USA), New York City (NY, USA), and Heinsberg (NRW, Germany), our model estimates the fraction of the population that has been infected and recovered by May 13, 2020 to 6.2% (95% CI: 3.3%-9.0%), 22.7% (95% CI: 15.7%-29.8%), and 20.5% (95% CI: 17.0%-24.3%). Our method traces the initial outbreak date in Santa Clara County back to January 20, 2020 (95% CI: January 16, 2020 - January 24, 2020). Our results could significantly change our understanding and management of the COVID-19 pandemic: A large asymptomatic population will make isolation, containment, and tracing of individual cases challenging. Instead, if needed, managing community transmission through increasing population awareness, promoting physical distancing, and encouraging behavioral changes could become more relevant.


Asymptomatic COVID-19 Have Longer Treatment Cycle Than Moderate Type of Confirmed Patients

Abstract: IMPORTANCE A kind of pneumonia caused by unknown causes that occurred in Wuhan, Hubei, China in December 2019, was reported as a result of novel coronavirus infection on January 7, 2020, and then WHO named it "COVID-19". The comparison of epidemiological and clinical characteristics for those patients between asymptomatic COVID-19 infections and moderate type of confirmed cases is limited. OBJECTIVE To compare the difference of epidemiology and clinical characteristics between asymptomatic COVID-19 infections and moderate type of confirmed cases. DESIGN, SETTING, AND PARTICIPANTS Retrospective, single-center cohort study of COVID-19 involving 52 infections of both 26 asymptomatic and 26 moderate type of confirmed cases in the recovery stage at Guizhou Provincial Staff Hospital in Guiyang, China, from January 29, to March 31, 2020; final date of follow-up was April 22. This study was registered in Chinese Clinical Trial Registry Center. EXPOSURES Documented the asymptomatic COVID-19 infections and moderate type of confirmed cases. MAIN OUTCOMES AND MEASURES Epidemiological, demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Epidemiological and clinical characteristics of asymptomatic COVID-19 infections and moderate type of confirmed cases were compared. RESULTS The median treatment cycle of asymptomatic COVID-19 infections was 16 days (interquartile range, 11-20 days) and longer than 13 days (interquartile range, 10-15 days) of moderate type of confirmed cases (p=0.049). The median incubation period of asymptomatic COVID-19 infections was 10 days (interquartile range, 0-21 days), while the control group was 7 days (interquartile range, 1-15 days) (p=0.27). On the initial chest computerized tomography (CT) check, 18 (69.2%, 18/26) asymptomatic COVID-19 infections were no imaging changes, which was of no significance compared with 12 (46.2%, 12/26) patients with moderate type of confirmed patients (p=0.092). CONCLUSIONS AND RELEVANCE In this single-center study, we found that asymptomatic COVID-19 infections have longer treatment cycle than those moderate type of confirmed cases.


The prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers with intensive exposure to COVID-19

Abstract: The prevalence of asymptomatic SARS-CoV-2 infection in healthcare workers with intensive exposure to COVID-19 is unclear. In this study, we investigated the seroprevalence of SARS-CoV-2 in 797 asymptomatic healthcare workers with intensive exposure to COVID-19 patients in Wuhan, China. Positive IgG was detected from 35 asymptomatic healthcare workers, and the prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers was 4.39% (35/797). None of them developed COVID-19 until May 15. 33 of them have performed at least one chest CT scan showing no viral pneumonia features, and 16 have finished at least one-time SARS-CoV-2 RNA detection with negative results. When contacting with the patients, 15 of them dressed with full personal protective equipment (PPE), and 16 worn N95 mask and gown. To the best of our knowledge, this is the first investigation reported that the seroprevalence of SARS-CoV-2 was 4.39% in asymptomatic healthcare workers with applied PPE in a high epidemic area, which may provide useful information of estimating asymptomatic infection rate in general population.


The natural history and transmission potential of asymptomatic SARS-CoV-2 infection

Abstract: Background: Little is known about the natural history of asymptomatic SARS-CoV-2 infection or its contribution to infection transmission. Methods: We conducted a prospective study at a quarantine centre for COVID-19 in Ho Chi Minh City, Vietnam. We enrolled quarantined people with RT-PCR-confirmed SARS-CoV-2 infection, collecting clinical data, travel and contact history, and saliva at enrolment and daily nasopharyngeal throat swabs (NTS) for RT-PCR testing. We compared the natural history and transmission potential of asymptomatic and symptomatic individuals. Results: Between March 10th and April 4th, 2020, 14,000 quarantined people were tested for SARS-CoV-2; 49 were positive. Of these, 30 participated in the study: 13(43%) never had symptoms and 17(57%) were symptomatic. 17(57%) participants acquired their infection outside Vietnam. Compared with symptomatic individuals, asymptomatic people were less likely to have detectable SARS-CoV-2 in NTS samples collected at enrolment (8/13 (62%) vs. 17/17 (100%) P=0.02). SARS-CoV-2 RNA was detected in 20/27 (74%) available saliva; 7/11 (64%) in the asymptomatic and 13/16 (81%) in the symptomatic group (P=0.56). Analysis of the probability of RT-PCR positivity showed asymptomatic participants had faster viral clearance than symptomatic participants (P<0.001 for difference over first 19 days). This difference was most pronounced during the first week of follow-up. Two of the asymptomatic individuals appeared to transmit the infection to up to four contacts. Conclusions: Asymptomatic SARS-CoV-2 infection is common and can be detected by analysis of saliva or NTS. NTS viral loads fall faster in asymptomatic individuals, but they appear able to transmit the virus to others.


Screening of healthcare workers for SARS-CoV-2 highlights the role of asymptomatic carriage in COVID-19 transmission

Abstract: Significant differences exist in the availability of healthcare worker (HCW) SARS-CoV-2 testing between countries, and existing programmes focus on screening symptomatic rather than asymptomatic staff. Over a 3-week period (April 2020), 1,032 asymptomatic HCWs were screened for SARS-CoV-2 in a large UK teaching hospital. Symptomatic staff and symptomatic household contacts were additionally tested. Real-time RT-PCR was used to detect viral RNA from a throat+nose self-swab. 3% of HCWs in the asymptomatic screening group tested positive for SARS-CoV-2. 17/30 (57%) were truly asymptomatic/pauci-symptomatic. 12/30 (40%) had experienced symptoms compatible with coronavirus disease 2019 (COVID-19) >7 days prior to testing, most self-isolating, returning well. Clusters of HCW infection were discovered on two independent wards. Viral genome sequencing showed that the majority of HCWs had the dominant lineage B{middle dot}1. Our data demonstrates the utility of comprehensive screening of HCWs with minimal or no symptoms. This approach will be critical for protecting patients and hospital staff.


Chest Computed Tomography Findings in Asymptomatic Patients with COVID-19

Abstract: Background: Little is known about the damage to the respiratory system in asymptomatic patients with coronavirus disease (COVID-19). Objective: Herein, we evaluated the findings of chest computed tomography (CT) and radiography in patients with COVID-19 who were asymptomatic. Methods: We retrospectively investigated patients with a confirmed diagnosis of COVID-19 but who did not show any symptoms. Among the 139 patients with COVID-19 who were hospitalized, 10 (7.2%) were asymptomatic. Their chest CT and radiographic findings were analyzed. Results: In the results, all patients (100%) had ground glass opacity (GGO) on chest CT. Further, the GGO lesions were predominantly distributed peripherally and posteriorly in all patients. In 9 (90%) patients, the GGO lesions were combined with reticular opacity. Air-bronchogram due to bronchiolectasis surrounded by GGO was observed in 8 patients (80%). Additionally, the lung lesions were dominant on the right side in all patients. Conclusions: In conclusion, considering our results that the lung is affected in asymptomatic patients, it will be necessary to extend the indications of COVID-19 testing for effective management of COVID-19 during the pandemic.


Asymptomatic animal traders prove positive for SARS virus.


Seroprevalence of IgG antibodies to SARS-coronavirus in asymptomatic or subclinical population groups.

Abstract: We systematically reviewed the current understanding of human population immunity against SARS-CoV in different groups, settings and geography. Our meta-analysis, which included all identified studies except those on wild animal handlers, yielded an overall seroprevalence of 0.10% [95% confidence interval (CI) 0.02-0.18]. Health-care workers and others who had close contact with SARS patients had a slightly higher degree of seroconversion (0.23%, 95% CI 0.02-0.45) compared to healthy blood donors, others from the general community or non-SARS patients recruited from the health-care setting (0.16%, 95% CI 0-0.37). When analysed by the two broad classes of testing procedures, it is clear that serial confirmatory test protocols resulted in a much lower estimate (0.050%, 95% CI 0-0.15) than single test protocols (0.20%, 95% CI 0.06-0.34). Potential epidemiological and laboratory pitfalls are also discussed as they may give rise to false or inconsistent results in measuring the seroprevalence of IgG antibodies to SARS-CoV.


COVID-19 Pneumonia in Asymptomatic Trauma Patients; Report of 8 Cases.

Abstract: We are currently involved in the novel coronavirus 2019 (COVID-19) pandemic. A considerable number of COVID-19 infected cases are asymptomatic but they can transmit the disease to others, especially healthcare workers. In this study, we reported 8 incidentally detected cases of COVID-19 pneumonia in chest computed tomography (CT) scan of patients referred to emergency department following multiple trauma without any respiratory symptoms.


Epidemiological and clinical features of asymptomatic patients with SARS-CoV-2 infection

Abstract: Few studies reported the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients with completely asymptomatic throughout the disease course. We investigated the epidemiological and clinical features of patients infected by SARS-CoV-2 without any symptoms. Patients with confirmed SARS-CoV-2 infection were retrospectively recruited. The demographic characteristics, clinical data, treatment, and outcomes of SARS-CoV-2 infected patients without any symptoms were analyzed. Fifteen (4.4%) of 342 SARS-CoV-2 infected patients did not develop any symptom during the course of the disease. The median time from exposure to diagnosis was 7.0 days (interquartile range [IQR]: 1.0-15.0 days). Of the 15 patients, 14 patients were diagnosed by tested positive for SARS-CoV-2 in throat swabs, while one patient was only tested positive for SARS-CoV-2 in anal swabs. During hospitalization, only 1 (6.7%) patient developed lymphopenia. Abnormalities of chest computed tomography examinations were detected in 8 (53.4%) patients on admission. As of 8 March 2020, all patients have been discharged. The median time of SARS-CoV-2 tested negative from admission was 7.0 days (IQR: 4.0-9.0 days). Patients without any symptoms but with SARS-CoV-2 exposure should be closely monitored and tested for SARS-CoV-2 both in anal and throat swabs to excluded the infection. Asymptomatic patients infected by SARS-CoV-2 have favorable outcomes.


COVID-19: asymptomatic carrier transmission is an underestimated problem

Abstract: At the present time, COVID-19 is spreading rapidly [1]. The global prevention and control of COVID-19 is focused on the estimation of the relevant incubation period, basic reproduction number (R0), effective reproduction number (Rt) and death risk. Although the prevention and control of COVID-19 requires a reliable estimation of the relevant incubation period, R0, Rt and death risk. Another key epidemiological parameter-asymptomatic ratio that provides strength and range for social alienation strategies of COVID-19, which is widely defined as the proportion of asymptomatic infections among all disease infections. In fact, the ratio of asymptomatic infection is a useful indicator of the burden of disease and a better measurement of the transmissibility of the virus. So far, people have not paid enough attention to asymptomatic carriers. The asymptomatic carriers discussed in this study are recessive infections, that is, those who have never shown symptoms after onset of infection. We will discuss three aspects: detection, infectivity and proportion of healthy carriers.


Asymptomatic and Human-to-Human Transmission of SARS-CoV-2 in a 2-Family Cluster, Xuzhou, China

Abstract: We report epidemiologic, laboratory, and clinical findings for 7 patients with 2019 novel coronavirus disease in a 2-family cluster. Our study confirms asymptomatic and human-to-human transmission through close contacts in familial and hospital settings. These findings might also serve as a practical reference for clinical diagnosis and medical treatment.


Asymptomatic COVID-19 infection in late pregnancy indicated no vertical transmission

Abstract: This study is to investigate the clinical characteristics of late pregnancy with asymptomatic 2019 novel coronavirus disease (COVID-19) infection, evaluate the outcome of maternal and fetal prognosis, and identify the evidence of intrauterine vertical transmission. A 22-years-old pregnant woman with asymptomatic COVID-19 infection who was admitted to our hospital on 11 February 2020 was enrolled in this study. Clinical data including laboratory test results and chest computed tomography (CT) scanning were collected and reviewed. Diagnosis of late pregnancy with asymptomatic COVID-19 infection was made. Lumbar anesthesia for cesarean section was performed and a female baby was delivered uneventfully, with the Apgar score of 9 to 10 points. Three times of COVID-19 nucleic acid test for the baby was negative after delivery. The puerpera returned to normal after the operation and two times of throat swab COVID-19 nucleic acid test were all negative after antiviral therapy. We reported an asymptomatic COVID-19 pregnant woman with detailed clinical information and our result indicated that for late pregnant women with asymptomatic COVID-19 infection, there might be no intrauterine infection caused by vertical transmission.


Hazardous Postoperative Outcomes of Unexpected COVID-19 Infected Patients: A Call for Global Consideration of Sampling All Asymptomatic Patients Before Surgical Treatment


Intraoperative Diagnosis of Coronavirus Disease 2019 in an Asymptomatic Patient: A Case Report

Abstract: Patients with coronavirus disease 2019 (COVID-19) with variable clinical presentations are encountered in the perioperative setting. While some have already been diagnosed and are symptomatic, others have undiagnosed, asymptomatic COVID-19. The latter group poses the greatest risk of transmission. Given limited capacities in most health care systems, diagnostic testing is mainly performed in symptomatic patients or those with relevant exposure. We report an intraoperative diagnosis of COVID-19 in an asymptomatic patient, prompted by clinical signs. To control a pandemic such as COVID-19, a high index of suspicion is pivotal when caring for asymptomatic patients in the perioperative setting.


Asymptomatic COVID-19 infection in pregnant woman in the third trimester: a case report/ 中华围产医学杂志

Abstract: We report a case of asymptomatic COVID-19 infection in a pregnant woman in the third trimester with good maternal and infant outcomes. The patient was admitted to the Second People's Hospital of Hefei on February 11, 2020, because of a "positive novel coronavirus nucleic acid test result for one day" at 38 weeks of gestation. No abnormality was observed during her previous regular prenatal examinations. A throat swab sample was obtained from the patient four days before admission due to the diagnosis of COVID-19 infection in her husband and sister on the 14th and 7th day before her admission, and the new coronavirus nucleic acid test showed positive. The patient reported no discomfort before admission. Chest CT on the 3rd after admission showed a small amount of bilateral pleural effusion. Irregular contractions occurred three days after admission and labor was considered to be imminent. An emergency cesarean section was performed and the patient delivered a live baby girl. No tests were performed on amniotic fluid, cord blood or placenta for new coronavirus nuclei acid. The patient was isolated from the infant without breastfeeding after surgery. All medical staff involved in the cesarean section were isolated after surgery. Neonatal peripheral blood and nasopharyngeal swabs were collected for the new coronavirus nucleic acid tests on the day of birth and one day of age respectively, and nasopharyngeal swabs and anal suabs were taken at nine days after birth. All test results were negative. The patient recovered well after surgery with stable vital signs. Chest CT on the 8th after operation showed a small amount of bilateral pleural effusion, while the new coronavirus nucleic acid test results of the pharyngeal swabs were positive on the 11th and 12th day after operation. The throat swabs of all medical staff involved in the operation were negative 14 days after the operation. The mother and baby were discharged 14 days after the Cesarean section.


Asymptomatic patients as a source of COVID-19 infections: A systematic review and meta-analysis

Abstract: BACKGROUND: Coronavirus Disease 2019 (COVID-19) is characterised by an unpredictable disease course, ranging from asymptomatic infections to severe, life-threating manifestations. Asymptomatic COVID-19 infections have been described, and the aim of this systematic review was to summarise their presentation form. METHODS: We searched PubMed® and Google® (1 December 2019 to 29 March 2020) and extracted age, laboratory findings, and computed tomography (CT) investigations. Pooled incidence rates of clinical characteristics were analysed using random effects models. RESULTS: In total, 506 patients from 34 studies (68 single cases and 438 from case series) with an asymptomatic course were identified. Patients with normal radiology were younger (19.59 ± 17.17 years) than patients with abnormal radiology (39.14 ± 26.70 years) (p value = 0.013). Despite being asymptomatic, CT investigations revealed abnormalities in 62.2% of the cases and ground glass opacities were most frequently observed (43.09% by meta-analysis). Most studies reported normal laboratory findings (61.74% by meta-analysis). CONCLUSIONS: More than half of patients without any symptoms present with CT abnormalities. Asymptomatic patients may be contagious and thus a potential source of transmission of COVID-19.


Asymptomatic COVID-19 Patients Can Contaminate Their Surroundings: an Environment Sampling Study

Abstract: The contamination of patients' surroundings by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains understudied. We sampled the surroundings and the air of six negative-pressure non-intensive care unit (non-ICU) rooms in a designated isolation ward in Chengdu, China, that were occupied by 13 laboratory-confirmed coronavirus disease 2019 (COVID-19) patients who had returned from overseas travel, including 2 asymptomatic patients. A total of 44 of 112 (39.3%) surface samples were positive for SARS-CoV-2 as detected by real-time PCR, suggesting extensive contamination, although all of the air samples were negative. In particular, in a single room occupied by an asymptomatic patient, four sites were SARS-CoV-2 positive, highlighting that asymptomatic COVID-19 patients do contaminate their surroundings and impose risks for others with close contact. Placement of COVID-19 patients in rooms with negative pressure may bring a false feeling of safety, and the importance of rigorous environment cleaning should be emphasized.IMPORTANCE Although it has been well recognized that the virus SARS-CoV-2, the causative agent of COVID-19, can be acquired by exposure to fomites, surprisingly, the contamination of patients' surroundings by SARS-CoV-2 is largely unknown, as there have been few studies. We performed an environmental sampling study for 13 laboratory-confirmed COVID-19 patients and found extensive contamination of patients' surroundings. In particular, we found that asymptomatic COVID-19 patients contaminated their surroundings and therefore imposed risks for other people. Environment cleaning should be emphasized in negative-pressure rooms. The findings may be useful to guide infection control practice to protect health care workers.


Comparison of clinical and epidemiological characteristics of asymptomatic and symptomatic SARS-CoV-2 infection: A multi-center study in Sichuan Province, China

Abstract: OBJECTIVES: Asymptomatic infection of SARS-CoV-2 has become a concern worldwide. This study aims to compare the epidemiology and the clinical characteristics of SARS-CoV-2 infection in asymptomatic and symptomatic individuals. METHODS: A total of 511 confirmed SARS-CoV-2 infection cases, including 100 asymptomatic (by the time of the pathogenic tests) and 411 symptomatic individuals were consecutively enrolled from January 25 to February 20, 2020 from hospitals in 21 cities and 47 counties or districts in Sichuan Province. Epidemiological and clinical characteristics were compared. RESULTS: Compared to the symptomatic patients, the asymptomatic cases were younger (P < 0.001), had similar co-morbidity percentages (P = 0.609), and came from higher altitude areas with lower population mobility (P < 0.001) with better defined epidemiological history (P < 0.001). 27.4% of well-documented asymptomatic cases developed delayed symptoms after the pathogenic diagnosis. 60% of asymptomatic cases demonstrated findings of pneumonia on the initial chest CT, including well-recognized features of coronavirus disease-19. None of the asymptomatic individuals died. Two elderly individuals with initially asymptomatic infection developed severe symptoms during hospitalization. One case of possible virus transmission by a patient during the incubation period was highly suspected. CONCLUSIONS: The epidemiological and clinical findings highlight the significance of asymptomatic infection with SARS-CoV-2. Inspecting the epidemiological history would facilitate the identification of asymptomatic cases. Evidence supports the chest CT scans for confirmed asymptomatic cases to evaluate the extent of lung involvement.


Covid-19: Nine in 10 pregnant women with infection when admitted for delivery are asymptomatic, small study finds


The time scale of asymptomatic transmission affects estimates of epidemic potential in the COVID-19 outbreak

Abstract: The role of asymptomatic carriers in transmission poses challenges for control of the COVID-19 pandemic. Study of asymptomatic transmission and implications for surveillance and disease burden are ongoing, but there has been little study of the implications of asymptomatic transmission on dynamics of disease. We use a mathematical framework to evaluate expected effects of asymptomatic transmission on the basic reproduction number R0 (i.e., the expected number of secondary cases generated by an average primary case in a fully susceptible population) and the fraction of new secondary cases attributable to asymptomatic individuals. If the generation-interval distribution of asymptomatic transmission differs from that of symptomatic transmission, then estimates of the basic reproduction number which do not explicitly account for asymptomatic cases may be systematically biased. Specifically, if asymptomatic cases have a shorter generation interval than symptomatic cases, R0 will be over-estimated, and if they have a longer generation interval, R0 will be under-estimated. Estimates of the realized proportion of asymptomatic transmission during the exponential phase also depend on asymptomatic generation intervals. Our analysis shows that understanding the temporal course of asymptomatic transmission can be important for assessing the importance of this route of transmission, and for disease dynamics. This provides an additional motivation for investigating both the importance and relative duration of asymptomatic transmission.


The relative transmissibility of asymptomatic COVID-19 infections among close contacts

Abstract: Asymptomatic transmission of the coronavirus disease 2019 is an important topic. A recent study in China showed that transmissibility of the asymptomatic cases is comparable to that of symptomatic cases. Here, we discuss that the conclusion may depend on how we interpret the data. To the best of our knowledge, this is the first time the relative transmissibility of asymptomatic COVID-19 infections is quantified.


How the asymptomatic population is influencing the COVID-19 outbreak in India?

Abstract: According to the current perception, symptomatic, presymptomatic, and asymptomatic infectious persons can infect the healthy population susceptible to the SARS-Cov-2. More importantly, various reports indicate that the number of asymptomatic cases can be several-fold higher than the reported symptomatic cases. In this article, we take the reported cases in India and various states within the country as the specimen to understand the progression of the COVID-19. Employing a modified SEIRD model, we predict the spread of COVID-19 by the symptomatic as well as asymptomatic infectious population. Considering reported infection primarily due to symptomatic we compare the model predicted results with the available data to estimate the dynamics of the asymptomatically infected population. Our data indicate that in the absence of the asymptomatic infectious population, the number of symptomatic cases would have been much less. Therefore, the current progress of the symptomatic infection can be reduced by quarantining the asymptomatically infectious population via extensive or random testing. This study is motivated strictly towards academic pursuit; this theoretical investigation is not meant for influencing policy decisions or public health practices.


Challenges of managing the asymptomatic carriers of SARS-CoV-2

Abstract: After an outbreak in Wuhan, China, a growing number of countries are now suffering from an epidemic by SARS-CoV-2, which causes COVID-19. Undoubtedly, reports of the skyrocketing global spread of COVID-19 has shocked people globally, from Japan to the United States. Presently, the World Health Organization indicates that the fatality rate due to COVID-19 is about 2%, inferring that many positive subjects may potentially overcome the illness with mild influenza-like symptoms and no need for hospitalization at intensive-care units. Because COVID-19 is completely new to the human immune system, many throughout the world are likely vulnerable to becoming sick after their initial exposure to SARS-CoV-2. Besides hospitalized cases, many individuals are likely asymptomatic but potentially carry the virus. While our knowledge about carriers and their virus shedding is deficient, some studies modelling the viral transmission have considered the potential contribution of the asymptomatic carriers. Protocols for managing asymptomatic cases, for example for controlling them to restrict their contact with healthy people at public places or private residences, have not been established. In-house quarantine may as well be applicable to asymptomatic cases if they could be identified and diagnosed. Presumably now, the asymptomatic subjects potentially contribute to the transmission of COVID-19 without their knowledge, intention, or being diagnosed as carriers. Thus, managing the asymptomatic subjects, who can carry and likely transmit the virus, is a major healthcare challenge while the pandemic is looming.


Covid-19: identifying and isolating asymptomatic people helped eliminate virus in Italian village


Characteristics of asymptomatic patients with SARS-CoV-2 infection in Jinan, China

Abstract: Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is continuously and rapidly circulating at present. Asymptomatic patients have been proven to be contagious and thus pose a significant infection control challenge. Here we describe the characteristics of asymptomatic patients with SARS-CoV-2 infection in Jinan, Shandong province, China. A total of 47 patients with confirmed COVID-19 were recruited. Among them, 11 patients were categorized as asymptomatic cases. We found that the asymptomatic patients in Jinan were relatively young and were mainly clustered cases. The laboratory indicators and lung lesion on chest CT were mild. No special factors were found accounting for the presence or absence of symptoms. The presence of asymptomatic patients increased the difficulty of screening. It is necessary to strengthen the identification of such patients in the future.


Asymptomatic transmission during the COVID-19 pandemic and implications for public health strategies

Abstract: SARS-CoV-2 spread rapidly within months despite global public health strategies to curb transmission by testing symptomatic patients and encouraging social distancing. Here, we summarize rapidly emerging evidence highlighting transmission by asymptomatic and pre-symptomatic individuals. Viral load of asymptomatic carriers is comparable to symptomatic patients, viral shedding is highest before symptom onset suggesting high transmissibility before symptoms. Within universally tested subgroups, surprisingly high percentages of COVID-19 positive asymptomatic individuals were found. Asymptomatic transmission was reported in several clusters. A Wuhan study showed an alarming rate of intrahospital transmission, and several countries reported higher prevalence among healthcare workers than the general population. This raises concern that health workers could act as silent disease vectors. Therefore, current public health strategies relying solely on 'symptom onset' for infection identification need urgent reassessment. Extensive universal testing irrespective of symptoms may be considered with priority placed on groups with high frequency exposure to positive patients.


Asymptomatic COVID-19: What the Neuroradiologist Needs to Know about Pulmonary Manifestations

Abstract: Coronavirus disease 2019 (COVID-19) is an infectious disease with a high asymptomatic incidence. Asymptomatic infections within a population will inevitably lead to diagnosis via unrelated medical imaging. We report the case of an asymptomatic patient undergoing a spine CT examination for trauma who was incidentally found to have lung abnormalities later confirmed to be COVID-19. We aim to familiarize neuroradiologists with the spectrum of COVID-19 pulmonary manifestations that are likely to be observed on neck and spine CT imaging.


The assessment of transmission efficiency and latent infection period on asymptomatic carriers of SARS-CoV-2 infection

Abstract: Few studies aimed on the transmission efficiency of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A follow-up study was performed on 147 asymptomatic carriers in Anhui Province. Of 147 asymptomatic carriers, 50.0% were male, 50.3% cases were older than 40 years, and 43.8% were farmers, 68.7% cases were from north of Anhui Province. There were 16 asymptomatic carriers developed illness in the following 14 days isolated observation, and diagnosed as confirmed cases. The possible latent infection period was evaluated ranged from one to five days before onset, and the median time was two days. The second attack rate of 16 confirmed cases whom transferred from asymptomatic carriers was 9.7% (23/236), while 131 asymptomatic carriers caused 2.6% (24/914) close contacts infection, there was a significant difference of second attack rate among two groups (Pï¼0.001). Our study indicated that COVID-19 cases are contagious during the incubation period, and the close contact screening should be covered the incubation period. Furthermore, the transmission efficiency of asymptomatic carriers was lower than that of confirmed cases.


FDG PET/CT Findings in an Asymptomatic Case of Confirmed COVID-19

Abstract: In the current and rapidly worsening pandemic, patients with COVID-19 may undergo imaging with FDG PET/CT. Because a significant proportion of infected patients may be asymptomatic, incidental discovery on a PET/CT scan performed for unrelated reasons can occur. Because of the highly infectious nature of this agent, it is important that interpreting physicians be aware of the typical imaging findings to identify potentially affected patients. We present the case of an asymptomatic patient referred for FDG PET/CT imaging of a lung nodule who demonstrated the typical CT findings of COVID-19 infection and was subsequently found to be positive on testing.


Covid-19: four fifths of cases are asymptomatic, China figures indicate


An Asymptomatic Patient with COVID-19


CT imaging and clinical course of asymptomatic cases with COVID-19 pneumonia at admission in Wuhan, China

Abstract: PURPOSE: Aimed to characterize the CT imaging and clinical course of asymptomatic cases with COVID-19 pneumonia. METHODS: Asymptomatic cases with COVID-19 pneumonia confirmed by SARS-COV-2 nucleic acid testing in Renmin Hospital of Wuhan University were retrospectively enrolled. The characteristics of CT imaging and clinical feature were collected and analyzed. RESULTS: 58 asymptomatic cases with COVID-19 pneumonia admitted to our hospital between Jan 1, 2020 and Feb 23, 2020 were enrolled. All patients had history of exposure to SARS-CoV-2. On admission, patients had no symptoms and laboratory findings were normal. The predominant feature of CT findings in this cohort was ground glass opacity (GGO) (55, 94.8%) with peripheral (44, 75.9%) distribution, unilateral location (34, 58.6%) and mostly involving one or two lobes (38, 65.5%), often accompanied by characteristic signs. After short-term follow-up, 16 patients (27.6%) presented symptoms with lower lymphocyte count and higher CRP, mainly including fever, cough and fatigue. The evolution of lesions on CT imaging were observed in 10 patients (17.2%). The average days of hospitalization was19.80±10.82 days, and was significantly longer in progression patients (28.60±7.55 day). CONCLUSION: CT imaging of asymptomatic cases with COVID-19 pneumonia has definite characteristics. Since asymptomatic infections as "covert transmitter", and some patients can progress rapidly in the short term. It is essential to pay attention to the surveillance of asymptomatic patients with COVID-19. CT scan has great value in screening and detecting patients with COVID-19 pneumonia, especially in the highly suspicious, asymptomatic cases with negative nucleic acid testing.


Asymptomatic case of Covid-19 in an infant with cystic fibrosis


Asymptomatic cases with SARS-CoV-2 infection

Abstract: On 31 March 2020, Chinese Health Authorization announced that numbers of asymptomatic cases with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will be made to the public daily. This was a very important step since different counties have different capacities for the detection of SARS-CoV-2 infection and control strategy for the Coronavirus Disease 2019 outbreak. We summarized the characteristics of asymptomatic SARS-CoV-2 infections and the transmission potential of asymptomatic cases. Then we provided guidelines for the management of asymptomatic cases through quarantine and nucleic acid/serology tests.


Epidemiological and Clinical Characteristics of 26 Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Carriers

Abstract: BACKGROUND: We retrospectively analyzed 26 persistently asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) carriers. METHODS: Epidemiological and clinical characteristics from the 26 asymptomatic patients with positive results for SARS-CoV-2 ribonucleic acid testing were obtained. RESULTS: Twenty-two patients (84.6%) correlated with clustering occurrence. The median period from contact to diagnosis and the last positive nucleic acid test was 19 (8-24 days) and 21.5 days (10-36 days), respectively. The median period from diagnosis to negative nucleic acid test was significantly different between patients with normal or atypical chest computed tomography (CT) findings (nâ =â 16, 61.5%; 7.5 days [2-20 days]) and patients with typical ground-glass or patchy opacities on CT (nâ =â 10, 38.5%; 12.5 days [8-22 days]; Pâ <â .01). Seven patients (70.0%) with initial positive nucleic acid test results had a negative result simultaneously with improved CT findings. Obvious improvement in CT findings was observed in 3 patients (30.0%) despite positive nucleic acid test results. CONCLUSIONS: In asymptomatic patients, changes in biochemical and inflammatory variables are small and changes on chest CT can occur. It is worth noting that the long existence of SARS-CoV-2 in some asymptomatic patients and false-negative results need to be considered in SARS-CoV-2 nucleic acid test.


Asymptomatic SARS-CoV-2 Infection in Household Contacts of a Healthcare Provider, Wuhan, China

Abstract: We found that all 5 asymptomatic household contacts of a Wuhan, China, physician with coronavirus disease had severe acute respiratory syndrome coronavirus 2 detected by PCR. The index patient and 2 contacts also had abnormal chest computed tomography scans. Asymptomatic infected household contacts of healthcare workers with coronavirus disease might be underrecognized.


Hydroxychloroquine-associated QT interval prolongation


Hydroxychloroquine: Corrected QT interval prolongation, first degree atrioventricular block and left bundle branch block during an off-label treatment with hydroxychloroquine for COVID-19 pneumonia: 3 case reports


Hydroxychloroquine: QTc prolongation following off-label-use: case report


Hydroxychloroquine and Potential Drug Interactions in Older Adults


Repurposing of well-known medications as antivirals: hydroxychloroquine and chloroquine; from HIV-1 infection to COVID-19.

Abstract: INTRODUCTION Chloroquine (CQ) and hydroxychloroquine (HCQ), originally were prescribed for prevention or treatment of malaria, but now successfully are used in several rheumatologic diseases. In addition, in recent decades considering their immunomodulatory effects, high tolerably and low cost, they are evaluated for various viral infections from HIV to COVID-19. AREAS COVERED In this review we tried to summarize all available studies on HCQ and CQ efficacy for management of viral infections and the probable mechanisms of action. The data were collected by searching "Hydroxychloroquine", "Choloroquine", "Viral infection", and names of various viral infections in PubMed/MEDLINE, Scopus, and Google Scholar databases from commencement to June 2020. Out of 95 search results, 74 most relevant works were gathered. EXPERT OPINION HCQ/CQ showed acceptable efficacy in HIV especially as an adjuvant treatment beside routine HAART. However, for some viral infections such as ZIKA, EBOLA, SARS-CoV and MERS-CoV, human studies are lacking. In the COVID-19 pandemic, in vitro and preliminary human studies showed encouraging findings. However, later well-designed trials and retrospective studies with large sample size, not only reported non-significant efficacy but also showed more cardiac adverse reactions. Alkalinisation of acid vesicles is the most important mechanism of action.


Research towards treating COVID-19.


Risk of QT Interval Prolongation Associated With Use of Hydroxychloroquine With or Without Concomitant Azithromycin Among Hospitalized Patients Testing Positive for Coronavirus Disease 2019 (COVID-19).

Abstract: Importance Administration of hydroxychloroquine with or without azithromycin for the treatment of coronavirus disease 2019 (COVID-19)-associated pneumonia carries increased risk of corrected QT (QTc) prolongation and cardiac arrhythmias. Objective To characterize the risk and degree of QT prolongation in patients with COVID-19 in association with their use of hydroxychloroquine with or without concomitant azithromycin. Design, Setting, and Participants This was a cohort study performed at an academic tertiary care center in Boston, Massachusetts, of patients hospitalized with at least 1 positive COVID-19 nasopharyngeal polymerase chain reaction test result and clinical findings consistent with pneumonia who received at least 1 day of hydroxychloroquine from March 1, 2020, through April 7, 2020. Main Outcomes and Measures Change in QT interval after receiving hydroxychloroquine with or without azithromycin; occurrence of other potential adverse drug events. Results Among 90 patients given hydroxychloroquine, 53 received concomitant azithromycin; 44 (48.9%) were female, and the mean (SD) body mass index was 31.5 (6.6). Hypertension (in 48 patients [53.3%]) and diabetes mellitus (in 26 patients [28.9%]) were the most common comorbid conditions. The overall median (interquartile range) baseline QTc was 455 (430-474) milliseconds (hydroxychloroquine, 473 [454-487] milliseconds vs hydroxychloroquine and azithromycin, 442 [427-461] milliseconds; P < .001). Those receiving concomitant azithromycin had a greater median (interquartile range) change in QT interval (23 [10-40] milliseconds) compared with those receiving hydroxychloroquine alone (5.5 [-15.5 to 34.25] milliseconds; P = .03). Seven patients (19%) who received hydroxychloroquine monotherapy developed prolonged QTc of 500 milliseconds or more, and 3 patients (3%) had a change in QTc of 60 milliseconds or more. Of those who received concomitant azithromycin, 11 of 53 (21%) had prolonged QTc of 500 milliseconds or more and 7 of 53 (13 %) had a change in QTc of 60 milliseconds or more. The likelihood of prolonged QTc was greater in those who received concomitant loop diuretics (adjusted odds ratio, 3.38 [95% CI, 1.03-11.08]) or had a baseline QTc of 450 milliseconds or more (adjusted odds ratio, 7.11 [95% CI, 1.75-28.87]). Ten patients had hydroxychloroquine discontinued early because of potential adverse drug events, including intractable nausea, hypoglycemia, and 1 case of torsades de pointes. Conclusions and Relevance In this cohort study, patients who received hydroxychloroquine for the treatment of pneumonia associated with COVID-19 were at high risk of QTc prolongation, and concurrent treatment with azithromycin was associated with greater changes in QTc. Clinicians should carefully weigh risks and benefits if considering hydroxychloroquine and azithromycin, with close monitoring of QTc and concomitant medication usage.


Caution Needed on the Use of Chloroquine and Hydroxychloroquine for Coronavirus Disease 2019.


Covid-19: US gives emergency approval to hydroxychloroquine despite lack of evidence.


Hydroxychloroquine against COVID-19: A critical appraisal of the existing evidence.

Abstract: Hydroxychloroquine (HCQ) has sparked much interest in the therapeutics of the Coronavirus Disease 2019 (COVID-19) pandemic. Its antiviral properties have been studied for years; regarding the Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2), it has been shown that HCQ may act at multiple levels. These extend from the initial attachment of the virus to the respiratory epithelium to the inhibition of its replication by the alkalinisation of the phagolysosome's microenvironment and the post-translational modification of certain viral proteins. Preliminary clinical evidence from China and France showed significant virological and clinical benefit in HCQ-treated patients, while other studies, mostly including critically ill patients, did not show favorable results. In this review, we critically appraise the existing evidence on HCQ against SARS-CoV-2 with particular emphasis on its protective and therapeutic role. Safety concerns that are relevant to the short-term HCQ use are also discussed. In the context of the rapid evolution of the COVID-19 pandemic that strains the health care systems worldwide and considering limited population-wide testing rates in most of the vulnerable countries, early empiric short-term administration of HCQ in symptomatic individuals, may be a promising, safe and low-cost strategy.


Hydroxychloroquine reduces the risk of covid-19 in patients with rheumatic diseases: myth or reality?


Facts and myths: Efficacies of repurposing chloroquine and hydroxychloroquine for the treatment of COVID-19.

Abstract: The emergence of coronavirus disease 2019 (COVID-19) is caused by the 2019 novel coronavirus (2019-nCoV). The 2019-nCoV first broke out in Wuhan and subsequently spreads worldwide owing to its extreme transmission efficiency. The fact that the COVID-19 cases and mortalities are reported in globally and the WHO has declared this outbreak as the pandemic. The international health authorities have focused on rapid diagnosis and isolation of patients as well as search for therapies able to counter the disease severity. Due to the lack of known specific, effective and proven therapies as well as the situation of public-health emergency, drug repurposing appears to be the best armour to find therapeutic solution against 2019-nCoV infection. Repurposing anti-malarial drugs, chloroquine (CQ)/ hydroxychloroquine (HCQ) have shown efficacy to inhibit most coronaviruses, including SARS-CoV-1 coronavirus. These CQ analogues have shown potential efficacy to inhibit 2019-nCoV in vitro that lead to focus in several future clinical trials. This review discusses the possible effective roles and mechanisms of CQ analogues for interfering with the 2019-nCoV replication cycle and infection.


Annals On Call - COVID-19: Is Chloroquine the Answer?


Chloroquine and hydroxychloroquine to treat COVID-19: between hope and caution.


Evidence of protective effect of hydroxychloroquine to prevent COVID-19.

Abstract: We would like to share ideas on the report on "Hydroxychloroquine in Patients with Rheumatic Disease Complicated by COVID-19: Clarifying Target Exposures and the Need for Clinical Trials [1]."Balevic noted that "well-designed clinical trials that include patients with rheumatic disease are urgently needed to characterize the efficacy, safety, and target exposures for hydroxychloroquine [1]."


An independent appraisal and re-analysis of hydroxychloroquine treatment trial for COVID-19.


The QT interval in patients with COVID-19 treated with hydroxychloroquine and azithromycin.


Experience with Hydroxychloroquine and Azithromycin in the COVID-19 Pandemic: Implications for QT Interval Monitoring

Abstract: Background: Despite a paucity of clinical evidence, hydroxychloroquine and azithromycin are being administered widely to patients with verified or suspected COVID-19. Both drugs may increase risk of lethal arrhythmias associated with QT interval prolongation. Methods: We performed a case series of COVID-19 positive/suspected patients admitted between 2/1/2020 and 4/4/2020 who were treated with azithromycin, hydroxychloroquine or a combination. We evaluated baseline and post-medication QT interval (QTc, Bazett) using 12-lead ECGs. Critical QTc prolongation was defined as: a) maximum QTc [≥]500 ms (if QRS <120 ms) or QTc [≥]550 (if QRS [≥]120 ms) and b) increased QTc of [≥]60 ms. Tisdale score and Elixhauser comorbidity index were calculated. Results: Of 490 COVID-19 positive/suspected patients, 314 (64%) received either/both drugs, and 98 (73 COVID-19 positive, 25 suspected) met study criteria (age 62{+/-}17 yrs, 61% male). Azithromycin was prescribed in 28%, hydroxychloroquine in 10%, and both in 62%. Baseline mean QTc was 448{+/-}29 ms and increased to 459{+/-}36ms (p=0.005) with medications. Significant prolongation was observed only in men (18{+/-}43 ms vs -0.2{+/-}28 ms in women, p=0.02). 12% of patients reached critical QTc prolongation. In a multivariable logistic regression, age, sex, Tisdale score, Elixhauser score, and baseline QTc were not associated with critical QTc prolongation (p>0.14). Changes in QTc were highest with the combination compared to either drug, with many-fold greater prolongation with the combination vs. azithromycin alone (17{+/-}39 vs. 0.5{+/-}40 ms, p=0.07). No patients manifested torsades de pointes. Conclusions: Overall, 12% of patients manifested critical QTc interval prolongation, and traditional risk indices failed to flag these patients. With the drug combination, QTc prolongation was several-fold higher compared to azithromycin alone. The balance between uncertain benefit and potential risk when treating COVID-19 patients with these drugs should be carefully assessed prior to use.


Hydroxychloroquine and azithromycin as potential treatments for COVID-19;clinical status impacts the outcome


A short therapeutic regimen based on hydroxychloroquine plus azithromycin for the treatment of COVID-19 in patients with non-severe disease. A strategy associated with a reduction in hospital admissions and complications.

Abstract: The new SARS-CoV-2 infection named COVID-19 has severely hit our Health System. At the time of writing this paper no medical therapy is officially recommended or has shown results in improving the outcomes in COVID-19 patients. With the aim of diminishing the impact in Hospital admissions and reducing the number of medical complications, we implemented a strategy based on a Hospital Home-Care Unit (HHCU) using an easy-to-use treatment based on an oral administration regimen outside the hospital with hydroxychloroquine (HCQ) plus azithromycin (AZM) for a short period of 5 days. Patients and methods: Patients [≥] 18 years old visiting the emergency room at the Hospital Universitario San Pedro de Logrono (La Rioja) between March, 31st and April, 12th diagnosed with COVID-19 with confirmed SARS-CoV-2 infection by a specific PCR, as follows: Patients with pneumonia (CURB [≤] 1) who did not present severe comorbidities and had no processes that contraindicated this therapeutic regime. Olygosimptomatic patients without pneumonia aged [≥] 55 years. Patients [≥] 18 years old without pneumonia with significant comorbidities. We excluded patients with known allergies to some of the antimicrobials used and patients treated with other drugs that increase the QTc or with QTc >450msc. The therapeutic regime was: HCQ 400 mg every twice in a loading dose followed by 200 mg twice for 5 days, plus AZM 500 mg on the first day followed by 250 mg daily for 5 days. A daily telephone follow-up was carried out from the hospital by the same physician. The end-points of our study were: 1.- To measure the need for hospital admission within 15 days after the start of treatment. 2.- To measure the need to be admitted to the intensive care unit (ICU) within 15 days after the start of the treatment. 3.- To describe the severity of the clinical complications developed. 4.- To measure the mortality within 30 days after starting treatment (differentiating if the cause is COVID-19 or something else). 5.-To describe the safety and adverse effects of the therapeutic regime. Results: During the 13 days studied a total of 502 patients were attended in the emergency room due to COVID-19. Forty-two were sent at home; 80 were attended by the HHCU (patients on this study) and 380 were admitted to the Hospital. In our series there were a group of 69 (85.18%) patients diagnosed with pneumonia (37 males and 32 females). Most of them, 57 (82.60%) had a CURB65 score of <1 (average age 49) and 12 (17.40%) a CURB score of 1 (average age 63). Eighteen (22.50%) of the pneumonia patients also had some morbidity as a risk factor. 11 patients (13.75%) without pneumonia were admitted to the HHCU because comorbidities or age [≥] 55 years. Six patients with pneumonia had to be hospitalized during the observation period, 3 of them because side effects and 3 because of worsening. One of these patients, with morbid obesity and asthma, had clinical worsening needing mechanical ventilation at ICU and developed acute distress respiratory syndrome. With the exception of the patient admitted to the ICU, the rest of the patients were discharged at home in the following 8 days (3 to 8 days). Twelve patients (15%), 11 of whom had pneumonia, experienced side effects affecting mainly the digestive. In another patient a QTc interval prolongation (452 msc) was observed. In total 3 of these patients had to be admitted in the Hospital, 2 because of vomiting and 1 because a QTc interval lengthening. None of the patients needed to stop the HCQ or AZM and all the 80 patients finished the therapeutic strategy. From the group without pneumonia only a patient developed diarrhea that did not require hospitalization or stop the medication. Conclusions: Our strategy has been associated with a reduction in the burden of hospital pressure, and it seems to be successful in terms of the number of patients who have developed serious complications and / or death. None of the patients died in the studied period and only 6 have to be admitted in conventional hospitalization area.


Similar incidence of Coronavirus Disease 2019 (COVID-19) in patients with rheumatic diseases with and without hydroxychloroquine therapy

Abstract: Background: Hydroxychloroquine is currently being tested as post-exposure prophylaxis against coronavirus disease 2019 (COVID-19) in several ongoing clinical trials. Objective: To compare the incidence of COVID-19 in Spanish patients with autoimmune rheumatic diseases treated with and without hydroxychloroquine. Methods: Retrospective electronic record review, from February 27th to April 16th, of patients with autoimmune inflammatory diseases followed at two academic tertiary care hospitals in Seville, Spain. The cumulative incidence of COVID-19, confirmed or suspected, was compared between patients with and without hydroxychloroquine as part of their treatment of autoimmune inflammatory diseases. Results: Among 722 included subjects, 290 (40%) were receiving hydroxychloroquine. During the seven-week study period, five (1.7% [95% CI: 0.5%-4.0%] cases of COVID-19 were registered among patients with hydroxychloroquine and five (1.2% [0.4%-2.7%]) (p=0.523) in without hydroxychloroquine. COVID-19 was confirmed by PCR in one (0.3%, 95% CI 0.008-1.9%) patient with hydroxychloroquine and two (0.5%, 95% CI 0.05%-1.6%) without hydroxychloroquine (p=1.0). One patient on hydroxychloroquine and two subjects without hydroxychloroquine were admitted to the hospital, none of them required to be transferred to the intensive care unit and no patient died during the episode. Conclusions: The incidence and severity of COVID-19 among patients with autoimmune rheumatic diseases with and without hydroxychloroquine was not significantly different. Hydroxychloroquine does not seem to be an appropriate therapy for post-exposure prophylaxis against COVID-19.


A recommendation for the use of chloroquine, hydroxychloroquine, primaquine, or tafenoquine for prophylaxis against the 2019 novel coronavirus (COVID-19) with note to the ophthalmic considerations

Abstract: With the ongoing pandemic of infectious disease termed coronavirus disease 2019 (COVID-19) caused by the novel coronavirus identified as severe acute respiratory syndrome coronavirus 2 (SARS-C0V-2), prevention of infection and spread is critical in preventing morbidity and mortality. Prophylaxis, specifically chemoprophylaxis, is particularly critical to breaking the spread and rapid rate of increase of SARS-CoV-2. Pre-exposure and post-exposure prophylaxis are both required components of this public health measure. As the use of anti-malarial agents, specifically the 4-aminoquinolones, chloroquine and hydroxychloroquine, for the treatment of SARS-CoV-2 is now being reported, attention must be turned to their role in the chemoprophylaxis of SARS-CoV-2. In a search of the peer-reviewed medical literature (using MEDLINE and cross-referenced literature), this report is first peer-reviewed publication to present the use of these anti-malarial agents as prophylaxis against SARS-CoV-2. The ophthalmic consideration of the use of these drugs is highlighted in this report.


Outcomes of Hydroxychloroquine Treatment Among Hospitalized COVID-19 Patients in the United States- Real-World Evidence From a Federated Electronic Medical Record Network

Abstract: On March 28, 2020, in response to the rapidly accelerating COVID-19 pandemic, U.S FDA issued emergency use authorization for hydroxychloroquine (HCQ) in hospitalized COVID-19 patients based on limited in-vitro and anecdotal clinical data. Analysis of the accumulated real-world data utilizing electronic medical records (EMR) could indicate HCQ therapy benefits as we await the results of clinical trials. However, any such analysis of retrospective observational data should account for variables such as demographics and comorbidities that could affect treatment strategies or outcomes. Therefore, we report the outcomes of HCQ treatment in a propensity-matched cohort of COVID-19 hospitalized patients. Our analysis of a large retrospective cohort of hospitalized COVID-19 patients treated with HCQ did not show benefits in mortality or the need for mechanical ventilation when compared to a matched cohort of patients who did not receive HCQ.


QT Interval Prolongation and Torsade De Pointes in Patients with COVID-19 treated with Hydroxychloroquine/Azithromycin

Abstract: Background: The emergence of the COVID-19 pandemic has resulted in over two million affected and over 150 thousand deaths to date. There is no known effective therapy for the disease. Initial reports suggesting the potential benefit of Hydroxychloroquine/Azithromycin (HY/AZ) have resulted in massive adoption of this combination worldwide. However, while the true efficacy of this regimen is unknown, initial reports have raised concerns regarding the potential risk of QT prolongation and induction of torsade de pointes (TdP). Methods: This is a multicenter retrospective study of 251 patients with COVID-19 treated with HY/AZ. We reviewed ECG tracings from baseline and until 3 days after completion of therapy to determine the progression of QTc and incidence of arrhythmia and mortality. Results: QTc prolonged in parallel with increasing drug exposure and incompletely shortened after its completion. Extreme new QTc prolongation to > 500 ms, a known marker of high risk for TdP had developed in 15.9% of patients. One patient developed TdP requiring emergent cardioversion. Seven patients required premature termination of therapy. The baseline QTc of patients exhibiting QTc prolongation of > 60 ms was normal. Conclusion: The combination of HY/AZ significantly prolongs the QTc in patients with COVID-19. This prolongation may be responsible for life threating arrhythmia in the form of TdP. This risk mandates careful consideration of HY/AZ therapy in lights of its unproven efficacy. Strict QTc monitoring should be performed if the regimen is given.


The Cardiac Toxicity of Chloroquine or Hydroxychloroquine in COVID-19 Patients: A Systematic Review and Meta-regression Analysis

Abstract: Abstract Importance The antimalarial agents chloroquine (CQ) and hydroxychloroquine (HCQ) have been proposed as a potential treatment for COVID-19 due their effect on several cellular processes that impact viral replication. Although more than 100 ongoing trials are testing their efficacy, CQ and HCQ are being used widely in clinical practice, exposing COVID-19 patients to potentially significant cardiac adverse effects. Objective To systematically review the literature and estimate the risk of cardiac toxicity in patients receiving CQ or HCQ for COVID-19. Data Sources A systematic search was conducted on May 27, 2020 of Ovid EBM Reviews, Ovid Embase (1974+), Ovid Medline (1946+ including epub ahead of print, in-process & other non-indexed citations), Scopus (1970+) and Web of Science (1975+) and preprint servers (Medrvix and ResearchSquare) and manual search of references lists. Study Selection Studies that included COVID-19 patients treated with CQ or HCQ, with or without azithromycin, were included as follows: (1) COVID-19 patient population, (2) the study included more than 10 patients receiving either one of the medications, (3) reported electrocardiographic changes and/or cardiac arrhythmias. Data Extraction and Synthesis Study characteristics and endpoints incidence were extracted. Due to the very low incidence of torsades de pointes (TdP) and other endpoints (rare events), the arcsine transformation was used to obtain a pooled estimate of the different incidences using a random-effects meta-analysis. Meta-regression analyses were used to assess whether the incidence of different endpoints significantly varied by multiple study-level variables specified a priori. Main Outcomes and Measures Pooled Incidence of: (1) change in QTc value from baseline [≥] 60 ms, (2) QTc [≥] 500 ms, (3) the composite of endpoint 1 and 2, (4) TdP arrhythmia or ventricular tachycardia (VT) or cardiac arrest, (5) discontinuation of treatment due to drug-induced QT prolongation or arrhythmias. Results A total of 19 studies with a total of 5652 patients were included. All included studies were of high methodological quality in terms of exposure ascertainment or outcome assessment. Among 2719 patients treated with CQ or HCQ, only two episodes of TdP were reported; the pooled incidence of TdP arrhythmia or VT or cardiac arrest was 3 per 1000, 95% CI (0-21), I2=96%, 18 studies with 3725 patients. Among 13 studies of 4334 patients, the pooled incidence of discontinuation of CQ or HCQ due to prolonged QTc or arrhythmias was 5%, 95% CI (1-11), I2=98%. The pooled incidence of change in QTc from baseline of [≥] 60 ms was 7%, 95% CI (3-14), I2=94% (12 studies of 2008 patients). The pooled incidence of QTc [≥] 500 ms was 6%, 95% CI (2-12), I2=95% (16 studies of 2317 patients). Among 11 studies of 3127 patients, the pooled incidence of change in QTc from baseline of [≥] 60 ms or QTc [≥] 500 ms was 9%, 95% CI (3-17), I2=97%. Mean/median age, coronary artery disease, hypertension, diabetes, concomitant QT prolonging medications, ICU care, and severity of illness in the study populations explained between-studies heterogeneity. Conclusions and Relevance Treatment of COVID-19 patients with CQ or HCQ is associated with a significant risk of drug-induced QT prolongation, which is a harbinger for drug-induced TdP/VT or cardiac arrest. CQ/HCQ use resulted in a relatively higher incidence of TdP as compared to drugs withdrawn from the market for this particular adverse effect. Therefore, these agents should be used only in the context of randomized clinical trials, in patients at low risk for drug-induced QT prolongation, with adequate safety monitoring.


Comparative in vitro transcriptomic analyses of COVID-19 candidate therapy hydroxychloroquine suggest limited immunomodulatory evidence of SARS-CoV-2 host response genes

Abstract: Hydroxychloroquine (HCQ) has emerged as a potential and controversial antiviral candidate therapy for COVID-19. While many clinical trials are underway to test the efficacy of HCQ as a treatment for COVID-19, underlying mechanisms of HCQ in the setting of COVID-19 remain unclear. Hence, we examined differential gene expression signatures of HCQ exposure, in vitro SARS-CoV-2 infection, and host signatures of COVID-19 in blood, bronchoalveolar lavage, and postmortem lung to evaluate whether HCQ transcriptome signatures associate with restoration of SARS-CoV-2-related host transcriptional responses. Here, we show that 24 hours of in vitro treatment of peripheral blood mononuclear cells(PBMC) with HCQ significantly impacted transcription of 16 genes involved in immune regulation and lipid metabolism. Using transcriptome data from in vitro SARS-CoV-2 infected NHBE and A549 cells and PBMC derived from confirmed COVID-19 infected patients, we determined that only 0.24% of the COVID-19 PBMC differentially expressed gene set and 0.39% of the in vitro SARS-CoV-2 cells differentially expressed gene set overlapped with HCQ-related differentially expressed genes. Moreover, we observed that HCQ treatment significantly impacted transcription of 159 genes in human primary monocyte-derived macrophages involved in cholesterol biosynthetic process and chemokine activity. Notably, when we compared the macrophage HCQ-related gene lists with genes transcriptionally altered during SARS-CoV-2 infection and in bronchoalveolar lavage of COVID-19+ patients, the CXCL6 gene was impacted in all three transcriptional signatures revealing evidence in favor of chemokine modulation. HCQ-related transcriptional changes minimally overlapped with host genes altered in postmortem lung biopsies from COVID-19 participants. These results may provide insight into the immunomodulation mechanisms of HCQ treatment in the setting of COVID-19 and suggest HCQ is not a panacea to SARS-CoV-2 infection.


Hydroxychloroquine and azithromycin plus zinc vs hydroxychloroquine and azithromycin alone: outcomes in hospitalized COVID-19 patients

Abstract: Background: COVID-19 has rapidly emerged as a pandemic infection that has caused significant mortality and economic losses. Potential therapies and means of prophylaxis against COVID-19 are urgently needed to combat this novel infection. As a result of in vitro evidence suggesting zinc sulfate may be efficacious against COVID-19, our hospitals began using zinc sulfate as add-on therapy to hydroxychloroquine and azithromycin. We performed a retrospective observational study to compare hospital outcomes among patients who received hydroxychloroquine and azithromycin plus zinc versus hydroxychloroquine and azithromycin alone. Methods: Data was collected from electronic medical records for all patients being treated with admission dates ranging from March 2, 2020 through April 5, 2020. Initial clinical characteristics on presentation, medications given during the hospitalization, and hospital outcomes were recorded. Patients in the study were excluded if they were treated with other investigational medications. Results: The addition of zinc sulfate did not impact the length of hospitalization, duration of ventilation, or ICU duration. In univariate analyses, zinc sulfate increased the frequency of patients being discharged home, and decreased the need for ventilation, admission to the ICU, and mortality or transfer to hospice for patients who were never admitted to the ICU. After adjusting for the time at which zinc sulfate was added to our protocol, an increased frequency of being discharged home (OR 1.53, 95% CI 1.12-2.09) reduction in mortality or transfer to hospice remained significant (OR 0.449, 95% CI 0.271-0.744). Conclusion: This study provides the first in vivo evidence that zinc sulfate in combination with hydroxychloroquine may play a role in therapeutic management for COVID-19.


Antimalarial drugs put to the test for COVID-19

Abstract: Over 200,000 people worldwide could receive the old antimalarial drugs chloroquine and hydroxychloroquine across more than 130 clinical trials designed to treat or prevent COVID-19, according to the US clinical trials database A small study in March suggested that hydroxychloroquine plus the antibiotic azithromycin helped people with COVID-19 recover faster President Donald J Trump touted hydroxychloroquine’s potential in the following weeks, spurring huge demand for the drug While some doctors prescribed it without proof, others scrambled to construct clinical studies to assess the drug’s efficacy The earliest results are discouraging A team of investigators in Brazil gave chloroquine to 81 hospitalized patients;32% of those who received high doses died, compared with 15% who received the low dose (medRxiv 2020, DOI: 10 1101/2020 04 07 20056424) Separately, data analyzed from 368 people with COVID-19 at hospitals run by the US Veterans Health Administration revealed that 28% who received hydroxychloroquine and 22% who got that View: PDF ;Full Text HTML


Perspectives on repositioning chloroquine and hydroxychloroquine for the treatment of Covid-19

Abstract: Coronavirus disease 2019 (COVID-19) is now spreading as a pandemic ravaging the whole world In the absence of a vaccine and an effective antiviral chemotherapy, there is currently an intense global interest in repositioning chloroquine (CQ) and its derivative hydroxychloroquine (HCQ) to combat the pandemic CQ has been used for decades for the treatment and prophylaxis against malaria in endemic countries It is readily available and has also been manufactured in these countries CQ is cheap, stable under field conditions and has been well tolerated as an antimalarial This experience could be adapted to deploy CQ or HCQ for prophylaxis or treatment of COVID19 if strong evidence could be generated for these uses We believe that well-designed drug trials should be initiated in malaria-endemic countries, taking into account the local context of the epidemic and the capacity of the health system in combating it In this paper, we are presenting the current status of evidence for using CQ and HCQ against COVID19


Influence of conflicts of interest on public positions in the COVID-19 era, the case of Gilead Sciences

Abstract: Fundings and gifts from the pharmaceutical industry have an influence on the decisions made by physicians and medical experts In the context of the COVID-19 epidemic, several treatments are available to treat patients infected with the virus Some are protected by patents, such as remdesivir, others are not, such as hydroxychloroquine We wanted to observe the possible correlation between the fact, for an academic doctor in infectious diseases, of having benefited from funding by Gilead Sciences, producer of remdesivir, and the public positions taken by this doctor towards hydroxychloroquine Our results show a correlation (correlation coefficient = 1) between the amount received from the Gilead Sciences company and public opposition to the use of hydroxychloroquine in France This should open up the debate on the role of the interest links of doctors with pharmaceutical companies in the medical and scientific public debate


Former FDA leaders decry emergency authorization of malaria drugs for coronavirus

Abstract: The recent Food and Drug Administration (FDA) emergency use authorization (EUA) for two malaria drugs to treat COVID-19, based on thin evidence of efficacy, has jeopardized research to learn the drugs’ real value against the pandemic coronavirus, say former agency executives under President Donald Trump and former President Barack Obama They also charge that the 28 March EUA for chloroquine phosphate and hydroxychloroquine sulfate undermines FDA’s scientific authority because it appeared to be a response not to scientific evidence, but to fervent advocacy of the drugs by Trump and other political figures FDA has multiple mechanisms to allow the use of unapproved, experimental drugs for small numbers of desperately ill patients outside of clinical trials Because chloroquine and hydroxychloroquine are approved for malaria, doctors could prescribe them “off label” for COVID-19 patients even without the EUA Since Trump first endorsed the drugs on 19 March, however, shortages have been reported, depriving some people with autoimmune disorders such as lupus who also depend on hydroxychloroquine The EUA will immediately add tens of millions of doses of the drugs for distribution to hospitalized COVID-19 patients through health care centers


Hydroxychloroquine is associated with slower viral clearance in clinical COVID-19 patients with mild to moderate disease: A retrospective study

Abstract: Background: There is conflicting data regarding the use of hydroxychloroquine (HCQ) in COVID-19 hospitalized patients Objective: To assess the efficacy of HCQ in increasing SARS-CoV-2 viral clearance Design: Retrospective observational study Setting: Cleveland Clinic Abu Dhabi Participants: Hospitalized adult patients with confirmed SARS-CoV-2 infection Intervention: None Measurements: The primary outcome was the time from a confirmed positive nasopharyngeal swab to turn negative. A negative nasopharyngeal swab conversion was defined as a confirmed SARS-CoV-2 case followed by two negative results using RT-PCR assay with samples obtained 24 hours apart Results: 34 confirmed COVID-19 patients were included. Nineteen (55.9%) patients presented with symptoms, and 14 (41.2%) had pneumonia. Only 21 (61.8%) patients received HCQ. The time to SARS-CoV-2 negativity nasopharyngeal test was significantly longer in patients who received HCQ compared to those who did not receive HCQ (17 [13-21] vs. 10 [4-13] days, p=0.023). HCQ was independently associated with time to negativity test after adjustment for potential confounders (symptoms, pneumonia or oxygen therapy) in multivariable linear regression analysis. On day 14, 47.8% (14/23) patients tested negative in the HCQ group compared to 90.9% (10/11) patients who did not receive HCQ (p=0.016). Limitations: Small sample size and retrospective design with a potential risk of selection bias Conclusion: HCQ was associated with a slower viral clearance in COVID-19 patients with mild to moderate disease. Data from ongoing randomized clinical trials with HCQ should provide a definitive answer regarding the efficacy and safety of this treatment.


[Potential harms associated with 4-aminoquinoline treatment].

Abstract: Hydroxychloroquine and chloroquine are currently being evaluated as treatment against COVID-19. These drugs are associated with some potential harms, including QTc-interval prolongation, hypoglycaemia, severe skin reactions and psychiatric effects. Use of hydroxychloroquine or chloroquine should be reserved to current indications or clinical trials, as recommended by several governmental medical products agencies.


Hydroxychloroquine for COVID-19: What is our Current State of Knowledge?

Abstract: Chloroquine and Hydroxychloroquine are drugs which have been widely used in malaria and rheumatoid arthritis respectively for over 50 years. There was anecdotal evidence of their efficacy in the earlier SARS outbreak in 2003. This prompted physicians from across the world to use them in the present SARS-CoV- 2 pandemic that is currently sweeping the globe, with 5 million people already infected to date. These drugs are already in widespread use for the treatment of COVID-19 in India, mainly because they are cheap and easily available, and because of the absence of any readily available alternative therapy. This timely review discusses the pre-clinical evidence, and data from the eight available clinical trials. We emphasise that careful monitoring for cardiac toxicity is required when these drugs are used. Finally, we conclude that current data does not allow us to recommend for or against the use of these drugs. Results of two large RCTs, one from the NIH and the other from WHO (Solidarity) are eagerly awaited before the role of these drugs in COVID-19 can be definitively established.


Risk of using hydroxychloroquine as a treatment of COVID-19

Abstract: The emerging COVID-19 pandemic poses a threat to the global health care system. Given the lack of antiviral therapies or vaccines for the disease, the antimalarial drug hydroxychloroquine (HCQ) obtained much attention as a treatment for COVID-19. However, there are limited and uncertain clinical data to support the beneficial effect of this drug in COVID-19 treatment. HCQ has several side effects and warnings, including blindness, heart failure, and renal toxicity, even with recommended doses. For severe cases of COVID-19 or in patients with preexisting conditions, administering such a drug could be fatal, particularly when taken at high doses or in combination with other antibiotics. However, further well-designed studies that would address the optimal dose, duration of treatment, possible side effects, and long-term usage outcomes are needed to make the final decision. In this paper, we aim to discuss the risk of using HCQ in treating COVID-19 patients, including its possible side effects.


COVID-19 in Patient with Sarcoidosis Receiving Long-Term Hydroxychloroquine Treatment, France, 2020

Abstract: Because of in vitro studies, hydroxychloroquine is under evaluation as a preexposure or postexposure prophylaxis for coronavirus disease (COVID-19) and as a possible COVID-19 curative treatment. We report a case of COVID-19 in a patient with sarcoidosis who was receiving long-term hydroxychloroquine treatment, despite adequate plasma concentrations.


Association of Treatment With Hydroxychloroquine or Azithromycin With In-Hospital Mortality in Patients With COVID-19 in New York State

Abstract: Importance: Hydroxychloroquine, with or without azithromycin, has been considered as a possible therapeutic agent for patients with coronavirus disease 2019 (COVID-19). However, there are limited data on efficacy and associated adverse events. Objective: To describe the association between use of hydroxychloroquine, with or without azithromycin, and clinical outcomes among hospital inpatients diagnosed with COVID-19. Design, Setting, and Participants: Retrospective multicenter cohort study of patients from a random sample of all admitted patients with laboratory-confirmed COVID-19 in 25 hospitals, representing 88.2% of patients with COVID-19 in the New York metropolitan region. Eligible patients were admitted for at least 24 hours between March 15 and 28, 2020. Medications, preexisting conditions, clinical measures on admission, outcomes, and adverse events were abstracted from medical records. The date of final follow-up was April 24, 2020. Exposures: Receipt of both hydroxychloroquine and azithromycin, hydroxychloroquine alone, azithromycin alone, or neither. Main Outcomes and Measures: Primary outcome was in-hospital mortality. Secondary outcomes were cardiac arrest and abnormal electrocardiogram findings (arrhythmia or QT prolongation). Results: Among 1438 hospitalized patients with a diagnosis of COVID-19 (858 [59.7%] male, median age, 63 years), those receiving hydroxychloroquine, azithromycin, or both were more likely than those not receiving either drug to have diabetes, respiratory rate >22/min, abnormal chest imaging findings, O2 saturation lower than 90%, and aspartate aminotransferase greater than 40 U/L. Overall in-hospital mortality was 20.3% (95% CI, 18.2%-22.4%). The probability of death for patients receiving hydroxychloroquine + azithromycin was 189/735 (25.7% [95% CI, 22.3%-28.9%]), hydroxychloroquine alone, 54/271 (19.9% [95% CI, 15.2%-24.7%]), azithromycin alone, 21/211 (10.0% [95% CI, 5.9%-14.0%]), and neither drug, 28/221 (12.7% [95% CI, 8.3%-17.1%]). In adjusted Cox proportional hazards models, compared with patients receiving neither drug, there were no significant differences in mortality for patients receiving hydroxychloroquine + azithromycin (HR, 1.35 [95% CI, 0.76-2.40]), hydroxychloroquine alone (HR, 1.08 [95% CI, 0.63-1.85]), or azithromycin alone (HR, 0.56 [95% CI, 0.26-1.21]). In logistic models, compared with patients receiving neither drug cardiac arrest was significantly more likely in patients receiving hydroxychloroquine + azithromycin (adjusted OR, 2.13 [95% CI, 1.12-4.05]), but not hydroxychloroquine alone (adjusted OR, 1.91 [95% CI, 0.96-3.81]) or azithromycin alone (adjusted OR, 0.64 [95% CI, 0.27-1.56]), . In adjusted logistic regression models, there were no significant differences in the relative likelihood of abnormal electrocardiogram findings. Conclusions and Relevance: Among patients hospitalized in metropolitan New York with COVID-19, treatment with hydroxychloroquine, azithromycin, or both, compared with neither treatment, was not significantly associated with differences in in-hospital mortality. However, the interpretation of these findings may be limited by the observational design.


Eritema multiforme inducido por hidroxicloroquina en paciente con COVID-19./ Eritema multiforme inducido por hidroxicloroquina en paciente con COVID-19./ Hydroxychloroquine-induced erythema multiforme in a patient with COVID-19


Chloroquine and hydroxychloroquine for COVID-19: A word of caution


COVID-19 coronavirus research has overall low methodological quality thus far: case in point for chloroquine/hydroxychloroquine

Abstract: OBJECTIVES/BACKGROUND AND OBJECTIVES: Prior epidemics of high-mortality human coronaviruses, such as the acute respiratory syndrome coronavirus (SARS-CoV or SARS-1) in 2003, have driven the characterization of compounds that could be possibly active against the currently emerging novel coronavirus SARS-CoV-2 (COVID-19). Presently, no approved treatment or prophylaxis is available for COVID-19. We comment on the existing COVID-19 research methodologies in general and the published reporting. Given the media attention and claims of effectiveness, we chose chloroquine and hydroxychloroquine, in combination with azithromycin, as an area of COVID-19 research to examine. METHODS/STUDY DESIGN AND SETTING: MEDLINE and EMBASE electronic databases were searched from 2019 to present (April 3rd, 2020) using a mix of keywords such as COVID-19 and chloroquine and hydroxychloroquine. We also searched the largest clinical medicine preprint repository, medRxiv.org. RESULTS: We found 6 studies, 3 randomized control trials and 3 observational studies, focusing on chloroquine and hydroxychloroquine (with azithromycin). We critically appraised the evidence. CONCLUSION: We found that the COVID-19 research methodology is very poor in the area of chloroquine/hydroxychloroquine research. In screening the literature, we observed the same across COVID-19 research in relation to potential treatments. The reporting is very poor and sparse, and patient-important outcomes needed to discern decision-making priorities are not reported. We do understand the barriers to perform rigorous research in health care settings overwhelmed by a novel deadly disease. However, this emergency pandemic situation does not transform flawed methods and data into credible results. The adequately powered, comparative, and robust clinical research that is needed for optimal evidence-informed decision-making remains absent in COVID-19.


Recommendations for the measurement of the QT interval during the use of drugs for COVID-19 infection treatment. Updatable in accordance with the availability of new evidence

Abstract: COVID-19 infection has shown rapid growth worldwide, and different therapies have been proposed for treatment, in particular, the combination of immune response modulating drugs such as chloroquine and hydroxychloroquine (antimalarials) alone or in combination with azithromycin. Although the clinical evidence supporting their use is scarce, the off label use of these drugs has spread very quickly in face of the progression of the epidemic and the high mortality rate in susceptible populations. However, these medications can pathologically prolong the QT interval and lead to malignant ventricular arrhythmias such that organized guidance on QT evaluation and management strategies are important to reduce morbidity associated with the potential large-scale use.


Of chloroquine and COVID-19

Abstract: Recent publications have brought attention to the possible benefit of chloroquine, a broadly used antimalarial drug, in the treatment of patients infected by the novel emerged coronavirus (SARS-CoV-2). The scientific community should consider this information in light of previous experiments with chloroquine in the field of antiviral research.


Risk of QT Interval Prolongation Associated With Use of Hydroxychloroquine With or Without Concomitant Azithromycin Among Hospitalized Patients Testing Positive for Coronavirus Disease 2019 (COVID-19)

Abstract: Importance: Administration of hydroxychloroquine with or without azithromycin for the treatment of coronavirus disease 2019 (COVID-19)-associated pneumonia carries increased risk of corrected QT (QTc) prolongation and cardiac arrhythmias. Objective: To characterize the risk and degree of QT prolongation in patients with COVID-19 in association with their use of hydroxychloroquine with or without concomitant azithromycin. Design, Setting, and Participants: This was a cohort study performed at an academic tertiary care center in Boston, Massachusetts, of patients hospitalized with at least 1 positive COVID-19 nasopharyngeal polymerase chain reaction test result and clinical findings consistent with pneumonia who received at least 1 day of hydroxychloroquine from March 1, 2020, through April 7, 2020. Main Outcomes and Measures: Change in QT interval after receiving hydroxychloroquine with or without azithromycin; occurrence of other potential adverse drug events. Results: Among 90 patients given hydroxychloroquine, 53 received concomitant azithromycin; 44 (48.9%) were female, and the mean (SD) body mass index was 31.5 (6.6). Hypertension (in 48 patients [53.3%]) and diabetes mellitus (in 26 patients [28.9%]) were the most common comorbid conditions. The overall median (interquartile range) baseline QTc was 455 (430-474) milliseconds (hydroxychloroquine, 473 [454-487] milliseconds vs hydroxychloroquine and azithromycin, 442 [427-461] milliseconds; P < .001). Those receiving concomitant azithromycin had a greater median (interquartile range) change in QT interval (23 [10-40] milliseconds) compared with those receiving hydroxychloroquine alone (5.5 [-15.5 to 34.25] milliseconds; P = .03). Seven patients (19%) who received hydroxychloroquine monotherapy developed prolonged QTc of 500 milliseconds or more, and 3 patients (3%) had a change in QTc of 60 milliseconds or more. Of those who received concomitant azithromycin, 11 of 53 (21%) had prolonged QTc of 500 milliseconds or more and 7 of 53 (13 %) had a change in QTc of 60 milliseconds or more. The likelihood of prolonged QTc was greater in those who received concomitant loop diuretics (adjusted odds ratio, 3.38 [95% CI, 1.03-11.08]) or had a baseline QTc of 450 milliseconds or more (adjusted odds ratio, 7.11 [95% CI, 1.75-28.87]). Ten patients had hydroxychloroquine discontinued early because of potential adverse drug events, including intractable nausea, hypoglycemia, and 1 case of torsades de pointes. Conclusions and Relevance: In this cohort study, patients who received hydroxychloroquine for the treatment of pneumonia associated with COVID-19 were at high risk of QTc prolongation, and concurrent treatment with azithromycin was associated with greater changes in QTc. Clinicians should carefully weigh risks and benefits if considering hydroxychloroquine and azithromycin, with close monitoring of QTc and concomitant medication usage.


Chloroquine and Hydroxychloroquine in the Era of SARS - CoV2: Caution on Their Cardiac Toxicity


Does pandemic justify the use of hydroxychloroquine for treatment and prevention of COVID-19 in India?


Antiretroviral HIV drugs in COVID-19 research: promises and risks. An opinion piece

Abstract: The unprecedented global scale of COVID-19 globally has triggered a race to discover interventions to reduce associated morbidity and mortality and rapid release of research findings prior to any degree of critical review. As with previous novel infection outbreaks, antiretrovirals are just one drug class that has been held up as a potential strategy for prophylaxis and treatment with scant evidence and risk of harm. Here we summarise the evidence for antiretrovirals to treat COVID-19 and, as a drug that has also been studied in HIV, hydroxychloroquine, and flag some of the pitfalls of using therapies that have not been evaluated robustly.


Can hydroxychloroquine protect patients with rheumatic diseases from COVID-19? Response to: 'Does hydroxychloroquine prevent the transmission of COVID-19?' by Heldwein and Calado and 'SLE, hydroxychloroquine and no SLE patients with COVID-19: a comment' by Joob and Wiwanitkit


CORRIGENDUM to Emergency Approval of Chloroquine and Hydroxychloroquine for Treatment of COVID-19 (updated to Emergency Authorization of Chloroquine and Hydroxychloroquine for Treatment of COVID-19)


Hydroxychloroquine against COVID-19: A critical appraisal of the existing evidence

Abstract: Hydroxychloroquine (HCQ) has sparked much interest in the therapeutics of the Coronavirus Disease 2019 (COVID-19) pandemic. Its antiviral properties have been studied for years; regarding the Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2), it has been shown that HCQ may act at multiple levels. These extend from the initial attachment of the virus to the respiratory epithelium to the inhibition of its replication by the alkalinisation of the phagolysosome's microenvironment and the post-translational modification of certain viral proteins. Preliminary clinical evidence from China and France showed significant virological and clinical benefit in HCQ-treated patients, while other studies, mostly including critically ill patients, did not show favorable results. In this review, we critically appraise the existing evidence on HCQ against SARS-CoV-2 with particular emphasis on its protective and therapeutic role. Safety concerns that are relevant to the short-term HCQ use are also discussed. In the context of the rapid evolution of the COVID-19 pandemic that strains the health care systems worldwide and considering limited population-wide testing rates in most of the vulnerable countries, early empiric short-term administration of HCQ in symptomatic individuals, may be a promising, safe and low-cost strategy.


Serious adverse drug reactions with hydroxychloroquine: a pharmacovigilance study in Vigibase®


Structure-based drug designing and immunoinformatics approach for SARS-CoV-2

Abstract: The prevalence of respiratory illness caused by the novel SARS-CoV-2 associated with multiple organ failures is spreading rapidly due to its contagious human-to-human transmission and inadequate global healthcare systems. Pharmaceutical re-use, reflecting an effective drug development technique using existing drugs, could shorten the time and reduce the costs relative to de novo drug discovery. We have performed virtual screening of antiviral compounds targeting the spike glycoprotein (S), main protease (M(pro)), and the SARS-CoV-2 RBD-ACE2 complex of SARS-CoV-2. PC786, an antiviral polymerase inhibitor, showed improved binding affinity toward all the targets. Furthermore, the post-fusion conformation of the trimeric S protein RBD domain with ACE2 revealed conformational changes associated with the PC786 drug binding. The proposed T cell and B cell epitope identification using the immunoinformatics approach could direct the experimental study with a higher probability of discovering appropriate vaccine candidates with fewer experiments and higher reliability.


The COVID-19 Gene and Drug Set Library

Abstract: The coronavirus (CoV) severe acute respiratory syndrome (SARS)-CoV-2 (COVID-19) pandemic has received rapid response by the research community to offer suggestions for repurposing of approved drugs as well as to improve our understanding of the COVID-19 viral life cycle molecular mechanisms. In a short period, tens of thousands of research preprints and other publications have emerged including those that report lists of experimentally validated drugs and compounds as potential COVID-19 therapies. In addition, gene sets from interacting COVID-19 virus-host proteins and differentially expressed genes when comparing infected to uninfected cells are being published at a fast rate. To organize this rapidly accumulating knowledge, we developed the COVID-19 Gene and Drug Set Library (https://amp.pharm.mssm.edu/covid19/), a collection of gene and drug sets related to COVID-19 research from multiple sources. The COVID-19 Gene and Drug Set Library is delivered as a web-based interface that enables users to view, download, analyze, visualize, and contribute gene and drug sets related to COVID-19 research. To evaluate the content of the library, we performed several analyses including comparing the results from 6 in-vitro drug screens for COVID-19 repurposing candidates. Surprisingly, we observe little overlap across these initial screens. The most common and unique hit across these screen is mefloquine, a malaria drug that should receive more attention as a potential therapeutic for COVID-19. Overall, the library of gene and drug sets can be used to identify community consensus, make researchers and clinicians aware of the development of new potential therapies, as well as allow the research community to work together towards a cure for COVID-19.


Coronavirus disease 2019: a clinical review.

Abstract: In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in Wuhan, China, and it subsequently spread in many countries around the world. Many efforts have been applied to control and prevent the spread of COVID-19, and many scientific studies have been conducted in a short period of time. Here we present an overview of the viral structure, pathogenesis, diagnosis, and clinical features of COVID-19 based on the current state of knowledge, and we compare its clinical characteristics with SARS and Middle East Respiratory Syndrome (MERS). Current researches on potentially effective treatment alternatives are discussed. We hope this review can help medical workers and researchers around the world contain the current COVID-19 pandemic.


The lysosome: A potential juncture between SARS-CoV-2 infectivity and Niemann-Pick disease type C, with therapeutic implications.

Abstract: Drug repurposing is potentially the fastest available option in the race to identify safe and efficacious drugs that can be used to prevent and/or treat COVID-19. By describing the life cycle of the newly emergent coronavirus, SARS-CoV-2, in light of emerging data on the therapeutic efficacy of various repurposed antimicrobials undergoing testing against the virus, we highlight in this review a possible mechanistic convergence between some of these tested compounds. Specifically, we propose that the lysosomotropic effects of hydroxychloroquine and several other drugs undergoing testing may be responsible for their demonstrated in vitro antiviral activities against COVID-19. Moreover, we propose that Niemann-Pick disease type C (NPC), a lysosomal storage disorder, may provide new insights into potential future therapeutic targets for SARS-CoV-2, by highlighting key established features of the disorder that together result in an "unfavorable" host cellular environment that may interfere with viral propagation. Our reasoning evolves from previous biochemical and cell biology findings related to NPC, coupled with the rapidly evolving data on COVID-19. Our overall aim is to suggest that pharmacological interventions targeting lysosomal function in general, and those particularly capable of reversibly inducing transient NPC-like cellular and biochemical phenotypes, constitute plausible mechanisms that could be used to therapeutically target COVID-19.


Novel Drugs Targeting the SARS-CoV-2/COVID-19 Machinery.

Abstract: Like other human pathogenic viruses, coronavirus SARS-CoV-2 employs sophisticated macromolecular machines for viral host cell entry, genome replication and protein processing. Such machinery encompasses SARS-CoV-2 envelope spike (S) glycoprotein required for host cell entry by binding to the ACE2 receptor, viral RNA-dependent RNA polymerase (RdRp) and 3-chymotrypsin-like main protease (3Clpro/Mpro). Under the pressure of the accelerating COVID-19 pandemic caused by the outbreak of SARSCoV- 2 in Wuhan, China in December 2019, novel and repurposed drugs were recently designed and identified for targeting the SARS-CoV-2 reproduction machinery, with the aim to limit spread of SARS-CoV-2 and morbidity and mortality of the COVID-19 pandemic.


Repurposing Nimesulide, a Potent Inhibitor of the B0AT1 Subunit of the SARS-CoV-2 Receptor, as a Therapeutic Adjuvant of COVID-19.

Abstract: The global pandemic caused by the SARS-CoV-2 infection is a health emergency that needs to be addressed immediately. The international scientific community, following World Health Organization (WHO) indications, launched different trials for testing drugs putatively able to block the SARS-CoV-2 infection or treat the COVID-19 disease symptoms. In parallel, studies devoted to a better understanding of SARS-CoV-2 biology are in the course for designing an effective vaccine. One of the human membrane proteins known to be docked by the virus is angiotensin-converting enzyme 2 (ACE2), proposed to be responsible for viral entry in target cells. Recently, the 3D structure of ACE2 has been obtained, showing its physical interaction with B0AT1 (SLC6A19), a plasma membrane transporter involved in the trafficking of amino acids in cells. The receptor targeted by SARS-CoV-2 is a supercomplex formed by a dimer of ACE2-B0AT1, in which ACE2 binds the viral protein and B0AT1 stabilizes the heterodimer. As a serendipity occurrence, nimesulide was shown to abolish the transport function of B0AT1. Here we suggest including nimesulide in the list of drugs to be tested for the identification of co-adjuvants in the treatment of COVID-19.