bluuebunny/crossref_metadata_2025 huggingface dataset:
Malaria Vectors in Areas of Plasmodium falciparum Epidemic Transmission in the Amazon Region, Brazil
Authors: da Rocha José Almir M. , de Oliveira Sabrina B. , Póvoa Marinete M. , Moreira Luciano A. , Krettli Antoniana Ursine
Published: September 2018

The main vectors of malaria in Brazil are Anopheles darlingi, An. aquasalis, and some species of the An. albitarsis complex, whereas others have questionable importance with regard to the disease transmission. To identify these vectors in the State of Pará, Brazil, in a high-prevalence P. falciparum area, 565 anophelines were captured and identified while the seasonal variation and daily biting activity were determined. Of the seven anopheline species (An. strodei, An. albitarsis s.l., An. rondoni, An. darlingi, An. triannulatus, An. oswaldoi, and An. nuneztovari), the plasmodia circumsporozoite protein (CSP) was detected in three of them, with a total infection rate of 6.2%. An. darlingi was the most prevalent species (22.4%), followed by An. albitarsis (5.2%) and An. rondoni (3.6%). An. rondoni was found to be infected for the first time, which was also confirmed through PCR. This result possibly represents a new malaria vector based on its highest frequency, biting and seasonal activities in the peak of malaria transmission.
Blood-stage Challenge for Malaria Vaccine Efficacy Trials: A Pilot Study with Discussion of Safety and Potential Value
Authors: Sanderson Frances , Andrews Laura , Douglas Alexander D. , Hunt-Cooke Angela , Bejon Philip , Hill Adrian V. S.
Published: September 2018

There is increasing interest in malaria vaccines targeting the asexual blood stage of Plasmodium falciparum. Without accepted immunologic correlates of clinical protection, challenge studies are useful for assessing the efficacy of candidate vaccines in vivo in healthy volunteers. We report a pilot study of a safe and robust challenge protocol using a blood-stage inoculum. We have applied well-validated trial endpoints and twice daily real-time quantitative polymerase chain reaction monitoring of parasitemia to blood-stage challenge, which enabled direct comparison with sporozoite challenge. We found that greater accuracy in quantification of blood-stage growth rates can be achieved with blood-stage challenge. This finding may provide greater power to detect partial efficacy of many blood-stage candidate vaccines. We discuss the potential utility of blood-stage challenge studies in accelerating malaria vaccine development.
Population Genetics and Phylogeography of Aedes aegypti (Diptera: Culicidae) from Brazil
Authors: Scarpassa Vera Margarete , Cardoza Tatiana Bacry , Cardoso Rubens P.
Published: September 2018

Population genetic analyses were conducted using samples of Aedes aegypti from 14 localities in the north, southeast, northeast, and central regions of Brazil. An 852-bp region of the mitochondrial DNA cytochrome oxidase I (COI) gene was used in the analyses. Ten haplotypes were observed, and cluster analyses revealed 2 groups (lineages) separated by 8 fixed mutations, suggesting that the Brazilian Ae. aegypti populations probably came from East and West Africa, with evidence of multiple introductions, one related to Group 1 and two related to Group 2. Considering all samples, genetic and geographic distances were significantly correlated (r2 = 0.332; P = 0.038), supporting the isolation by distance (IBD) model, but no correlation was detected for any particular region, which is consistent with human migrations and trade exchanges. Genetic distances (pairwise FST and Nm values), AMOVA, and cluster analyses indicated a deep genetic structure for the Brazilian Ae. aegypti, probably resulting from several factors: multiple introductions associated with distinct lineages, geographic differentiation (IBD), passive dispersal patterns, control activities, extinction and recolonization events, and genetic drift.
Artemether Treatment of Prepatent Schistosoma japonicum Induces Resistance to Reinfection in Association with Reduced Pathology
Authors: Bartley Paul B. , Glanfield Amber , Li Yuesheng , Stanisic Danielle I. , Duke Mary , Jones Malcolm K. , McManus Donald P.
Published: September 2018

Artemether (ART) is a well-described antimalarial with efficacy against juvenile schistosomes, with 7-day-old schistosomula being particularly susceptible. Both ART-affected worms and parasites developing from irradiated cercariae die at similar times after infection. Our aim was to determine if ART treatment of prepatent schistosomiasis japonica may result in the generation of a protective immune response. Female CBA mice were treated with a single dose of ART at defined time points after percutaneous infection with a virulent Chinese mainland strain of Schistosoma japonicum. Half of the mouse cohorts were subjected to homologous parasite strain reinfection after drug treatment to assess protective effects of ART therapy. Two independent trials demonstrated that a statistically significant (58% and 50%) reduction in challenge worm burden occurred after reinfection of those mice treated with ART at two weeks p.i. A reduction in the IL-4 response to soluble worm antigen preparation (SWAP) was also seen in ART-treated mice but with no correlation to reinfection resistance. In the Chinese mainland strain used, ART treatment of prepatent infection at the appropriate time point induced resistance to reinfection. There was also an anti-pathology effect observed in ART-treated mice that remained significant after reinfection.
Case-control Study of Armadillo Contact and Hansen’s Disease
Authors: Clark Brychan M. , Murray Clinton K. , Horvath Lynn L. , Deye Gregory A. , Rasnake Mark S. , Longfield Robert N.
Published: September 2018

Hansen’s disease (HD) continues to have worldwide impact despite efforts to eradicate the disease. Although a definitive transmission mode has not been identified, data supports an association between HD and contact with the nine-banded armadillo. We conducted a case-control study of 28 HD patients to determine if there is an association between armadillo exposure and HD. There was no association between HD and place of birth or having hunted, consumed, or had direct or indirect contact with deer, birds, or squirrels. Univariate analysis showed that residence in Mexico (P = 0.001), hunting rabbits (P = 0.04), cleaning rabbits (P < 0.001), and armadillo exposure from hunting (P = 0.005), cleaning (P = 0.004), consuming (P = 0.002) them, or having direct armadillo contact (P = 0.017) were associated with HD. Multivariate analysis showed that eating armadillos (P = 0.039, odds ratio [OR] = 3.65, 95% confidence interval [CI] = 1.07–12.4), cleaning rabbits (P = 0.018, OR = 4.08, 95% CI = 1.27–13.1), and having lived in Mexico (P = 0.006, OR = 24.9, 95% CI = 2.52–245) were associated with HD.
Risk Factors Associated with Life-threatening Rickettsial Infections
Authors: Lee Nelson , Ip Margaret , Wong Bonnie , Lui Grace , Tsang Owen Tak Yin , Lai Jak Yiu , Choi Kin Wing , Lam Rebecca , Ng Tak Keung , Ho Jenny , Chan Yin Yan , Cockram Clive S. , Lai Sik To
Published: September 2018

We retrospectively analyzed 92 cases of severe rickettsial infections in patients (median age = 49 years, 57% male, 37.0% with scrub typhus) in Hong Kong. Immunofluorescence assay was used for diagnostic confirmation. Identification of ≥ 1 diagnostic sign (exposure history, rash, or eschar) was possible in 94.6% of the cases. Multivariate analysis suggested that pulmonary infiltrates (odds ratio [OR] = 25.2, 95% confidence interval [CI] = 3.9–160.9, P = 0.001) and leukocytosis (OR = 1.3, 95% CI = 1.0–1.5 per unit increase, P = 0.033) were independent predictors of admission to an intensive care unit (14.1%). Delayed administration of doxycycline was independently associated with major organ dysfunction (23.9%; oxygen desaturation, renal failure, severe jaundice, encephalopathy, cardiac failure) (OR = 1.2, 95% CI = 1.0–1.5 per day delay, P = 0.046; adjusted for age and rickettsia biogroup) and prolonged hospitalization > 10 days (25%) (OR = 1.4, 95% CI = 1.1–1.9 per day delay, P = 0.014). Treatment with fluoroquinolone/clarithromycin did not correlate with clinical outcomes (P > 0.05). Early empirical doxycycline therapy should be considered if clinico-epidemiologic signs of rickettsial infections are present.
The Chulli Water Purifier: Acceptability and Effectiveness of an Innovative Strategy for Household Water Treatment in Bangladesh
Authors: Gupta Sundeep K. , Islam M. S. , Johnston Richard , Ram Pavani Kalluri , Luby Stephen P.
Published: September 2018

To evaluate the effectiveness of the chulli water purifier, a new household water treatment strategy in Bangladesh that relies on passing water through a stove, we interviewed persons who had this water purifier. From households using it regularly, we tested untreated water, sand-filtered water without heat pasteurization, sand-filtered and heat pasteurized water, and household stored, treated water. Reasons for discontinuing use among 80 of 101 persons included mechanical problems (49%), inconvenience (35%), and high cost (10%). Only four households were regularly using the purifier. Three (19%) of 16 heat-treated samples were positive for Escherichia coli. The median log reduction from source water was > 5. Nine (56%) stored water samples were positive for E. coli, indicating recontamination. Poor durability, inconvenience, high cost, and post-treatment contamination limit the usefulness of the purifier. These issues, which are relevant for other household water treatment strategies, should be resolved before further implementation.
Prevalence and Genetic Diversities of Hantaviruses in Rodents in Beijing, China
Authors: Jiang Jia-Fu , Zuo Shu-Qing , Zhang Wen-Yi , Wu Xiao-Ming , Tang Fang , De Vlas Sake J. , Zhao Wen-Juan , Zhang Pan-He , Dun Zhe , Wang Ri-Ming , Cao Wu-Chun
Published: September 2018

A total of 835 rodents captured in Beijing, China, were tested for hantavirus infection. Fifty-five (6.6%) were positive for viral RNA when lung tissue samples were examined by reverse transcriptase-polymerase chain reaction. Of 666 sera collected from the above rodents, 50 (7.5%) were positive for IgG antibody by ELISA. Among the 50 seropositive rodents, 37 were positive for viral RNA. In addition, five rodents were positive for viral RNA but negative for IgG antibody. The infection rates among study sites (χ2 = 28.93, df = 8, P = 0.001) and habitats (χ2 = 22.88,df = 7, P = 0.02) were significantly different. The sequences of partial M-segment of hantaviruses detected in 11 representative rodents had 0.1–8.2% divergence. Phylogenetic analysis showed that our hantavirus sequences fell into three different lineages regardless of geographical origin or rodent species. A strain detected from a trading center of agricultural products, which might be imported from other provinces, was genetically different from other strains of Beijing.
Failure of Japanese Encephalitis Vaccine and Infection in Inducing Neutralizing Antibodies against West Nile Virus, People’s Republic of China
Authors: Tang Fang , Zhang Jiu-Song , Liu Wei , Zhao Qui-Min , Zhang Fang , Wu Xiao-Ming , Yang Hong , Ly Hinh , Cao Wu-Chun
Published: September 2018

We examined whether live attenuated Japanese encephalitis (JE) vaccine is effective in preventing West Nile virus (WNV) infection in the People’s Republic of China. Three groups were recruited into the study: patients with Japanese encephalitis (JE), healthy controls vaccinated with live attenuated 2 SA14-14-vaccine against JE virus (JEV), and unvaccinated healthy controls. Serum samples were collected and screened for IgG antibodies against JEV by an indirect immunofluorescence assay. Positive samples were then analyzed for levels of antibodies against JEV and neutralizing antibodies against West Nile virus (WNV) by a plaque-reduction neutralization test (PRNT). Although most persons had medium to high levels of JEV-reactive IgG and neutralizing antibodies, only 2 of the 82 unvaccinated control samples were positive for the WNV-reactive antibodies. These findings suggest that previous JEV infection or vaccination did not induce adequate levels of WNV-reactive antibodies in the population studied. However, how these persons would respond to a secondary flavivirus infection and whether their prior experience with wild-type or attenuated JE vaccine will provide some cross-protection against WNV disease still warrants further investigation.
Comparative Evaluation of Three Assays for Measurement of Dengue Virus Neutralizing Antibodies
Authors: Putnak J. Robert , de la Barrera Rafael , Burgess Timothy , Pardo Jorge , Dessy Francis , Gheysen Dirk , Lobet Yves , Green Sharone , Endy Timothy P. , Thomas Stephen J. , Eckels Kenneth H. , Innis Bruce L. , Sun Wellington
Published: September 2018

Plaque reduction neutralization tests (PRNTs) are commonly used for measuring levels of dengue virus (DENV) neutralizing antibodies. However, these assays lack a standardized format, generally have a low sample throughput, and are labor-intensive. The objective of the present study was to evaluate two alternative DENV neutralizing antibody assays: an enzyme-linked immunosorbent assay–based microneutralization (MN) assay, and a fluorescent antibody cell sorter–based, DC-SIGN expresser dendritic cell (DC) assay. False-positive rates, serotype specificity, reproducibility, sensitivity, and agreement among the assay methods were assessed using well-characterized but limited numbers of coded test sera. Results showed that all three assays had false-positive rates of less than 10% with titers near the cut-off and generally below the estimated limits of detection. All three methods demonstrated a high degree of specificity and good agreement when used to assay sera and serum mixtures from monovalent vaccinees and sera from patients after primary natural infection, with the only notable exception being moderate-to-high neutralizing antibody titers against DENV 2 measured by PRNT in a mixture containing only DENV 3 and DENV 4 sera. The MN and DC assays demonstrated good reproducibility. All three assays were comparable in their sensitivity, except that the PRNT was less sensitive for measuring DENV 4 antibody, and the MN and DC assays were less sensitive for measuring DENV 2 antibody. However, when used to test sera from persons after tetravalent DENV vaccination or secondary DENV infection, there was poor specificity and poor agreement among the different assays.
Epidemiological and Clinical Observations on Patients with Dengue in Puerto Rico: Results from the First Year of Enhanced Surveillance—June 2005–May 2006
Authors: Ramos Mary M. , Argüello D. Fermin , Luxemburger Christine , Quiñones Luz , Muñoz Jorge L. , Beatty Mark , Lang Jean , Tomashek Kay M.
Published: September 2018

From June 2005 to May 2006, a clinic-based enhanced surveillance system for dengue was implemented in a Puerto Rican municipality to provide a population-based measure of disease incidence and clinical outcomes. We obtained demographic and clinical information from suspected cases and performed serologic and virologic testing. We used World Health Organization (WHO) criteria to classify cases and applied a simplified case definition for severe dengue illness. There were 7.7 laboratory-positive cases of dengue per 1,000 population. The highest incidence, 13.4 per 1,000, was among 10 to 19 year olds. Of the 156 laboratory-positive cases, three patients (1.9%) met WHO criteria for dengue hemorrhagic fever, and 30 patients (19.2%) had at least one severe clinical manifestation of dengue infection. Our data suggest that in a community with endemic dengue, enhanced surveillance is useful for detecting symptomatic infections. Furthermore, the simplified case definition for severe dengue may be useful in clinic-based surveillance.
An Animal Model for Studying the Pathogenesis of Chikungunya Virus Infection
Authors: Ziegler Sarah A. , Lu Liang , da Rosa Amelia P. A. Travassos , Xiao Shu-Yuan , Tesh Robert B.
Published: September 2018

Newborn and 14-day-old mice inoculated subcutaneously with chikungunya virus (CHIKV) developed lethargy, difficulty walking, dragging of hind limbs, and reduced weight gain within 7–10 days after infection (PI). During the initial 6–7 days PI, the animals had viremia; high levels (106–108 PFU) of CHIKV were also present in leg muscle. The virus persisted in muscle for several days after viremia disappeared. The major histopathologic changes were in skeletal muscle, which were focal necrosis and inflammation, followed by fibrosis and dystrophic calcification. Some mice also showed dystrophic calcification in the joint cartilage, but there were few deaths, and most of the animals eventually recovered. CHIKV antigen was shown by immunohistochemistry in the muscle for several weeks after infection. Based on the clinical and pathologic similarities with CHIKV infection in humans, young ICR and CD-1 mice offer a useful and realistic model for further study of the pathogenesis and treatment of CHIKV infection.
Clinical and Laboratory Characteristics and Risk Factors for Fatality in Elderly Patients with Dengue Hemorrhagic Fever
Authors: Lee Ing-Kit , Liu Jien-Wei , Yang Kuender D.
Published: September 2018

To better understand the clinical and laboratory characteristics and to identify risk factor(s) for fatality in elderly patients with dengue hemorrhagic fever (DHF), 66 elderly (age ≥ 65 years) and 241 non-elderly adults (age, 19–64 years) with DHF were retrospectively analyzed. Compared with non-elderly adults, elderly individuals had significantly lower incidences of fever (P = 0.002), abdominal pain (P = 0.003), bone pain (P < 0.001), and skin rashes (P = 0.002); higher frequencies of concurrent bacteremia (P = 0.049), gastrointestinal bleeding (P = 0.044), acute renal failure (P = 0.001), and pleural effusion (P < 0.010); higher incidence of prolonged prothrombin time (P = 0.025); lower mean hemoglobin level (P < 0.001); longer hospitalization (P = 0.049); and a higher fatality rate (P = 0.006). Five elderly patients with DHF died. When compared with non-fatal elderly patients with DHF, a significant higher frequency in men (P = 0.019), those with chronic obstructive pulmonary disease (P = 0.008), those with dengue shock syndrome (DSS; P < 0.001), and those with acute renal failure (P < 0.001) was found in the elderly counterparts that died. Multivariate analysis showed that only DSS (odd ratio = 77.33, P = 0.001) was an independent risk factor for fatality in elderly patients.
Pathogenesis of XJ and Romero Strains of Junin Virus in Two Strains of Guinea Pigs
Authors: Yun Nadezhda E. , Linde Nathaniel S. , Dziuba Natallia , Zacks Michele A. , Smith Jeanon N. , Smith Jennifer K. , Aronson Judy F. , Chumakova Olga V. , Lander Heather M. , Peters Clarence J. , Paessler Slobodan
Published: September 2018

Argentine hemorrhagic fever (AHF), a systemic infectious disease caused by infection with Junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. We compared the virulence of two Junin virus strains in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. Our data indicate that this passage of the XJ strain is attenuated in guinea pigs. In contrast, the Romero strain is highly virulent in Strain 13 as well as in Hartley guinea pigs, resulting in systemic infection, thrombocytopenia, elevated apartate aminotransferase levels, and ultimately, uniformly lethal disease. We detected viral antigen in formalin-fixed, paraffin-embedded tissues. Thus, both guinea pig strains are useful animal models for lethal Junin virus (Romero strain) infection and potentially can be used for preclinical trials in vaccine or antiviral drug development.
Pharmacokinetic and Pharmacodynamic Evaluation of Intramuscular Artesunate in Healthy Beagle Dogs
Authors: Bennett Kent , Si Yuanzheng , Steinbach Thomas , Zhang Jing , Li Qigui
Published: September 2018

Pharmacokinetic and pharmacodynamic responses were evaluated after intramuscular (IM) injection of artesunate (AS). Twelve dogs were injected with IM AS at 2.5, 5, or 10 mg/kg into the left gluteal muscle. A second injection of only diluent was given in the right gluteal muscle. At 24 hours post-injection, plasma creatine kinase (CK) concentrations were elevated above normal. Muscle biopsies showed myocyte necrosis and acute inflammation, which was worse on the treated side. At 7 days after injection, CK concentrations were normal. Muscle biopsies showed mineralization, fibrosis, and chronic inflammation with less difference between sides. Compared with intravenous administration, IM AS resulted in a prolonged half-life for both AS and DHA. Intramuscular AS also had a lower mean dose-adjusted Cmax and a higher mean dose-adjusted area under the curve; but produced similar concentrations of dihydroartemisinin. These findings suggest that adverse reactions to IM artesunate are minor and temporary which justify further study of this route in treating severe malaria.
Clinical Characteristics and National Economic Cost of the 2005 Dengue Epidemic in Panama
Authors: Armien Blas , Suaya Jose A. , Quiroz Evelia , Sah Binod K. , Bayard Vicente , Marchena Loyd , Campos Cornelio , Shepard Donald S.
Published: September 2018

In 2005, Panama experienced the largest dengue epidemic since 1993. We conducted both a prospective clinical and a national economic study. The full cost analysis measured costs of dengue cases and of dengue control efforts in the entire country. Costs are in 2005 US$. Ambulatory patients were 130 of the 136 participants, with 82% adults (18+) and 62% women. Duration of fever and illness averaged 6.1 (standard deviation [SD], 5.3) and 21.2 (SD 13.5) days, respectively. Loss in quality of life averaged 67% (SD 21) during the worst days of illness. An average ambulatory and hospitalized case cost $332 and $1,065, respectively. Although 5,489 cases were officially reported, the Ministry of Health (MOH) estimated 32,900 actual cases, implying a total cost of $11.8 million. Additionally, estimated government spending on dengue control efforts was $5 million. This dengue epidemic had a major disease impact and an economic cost of $16.9 million ($5.22 per capita).
Acute Respiratory Distress Syndrome in a Case of Plasmodium ovale Malaria
Authors: Rojo-Marcos Gerardo , Cuadros-González Juan , Mesa-Latorre José María , Culebras-López Ana María , de Pablo-Sánchez Raúl
Published: September 2018

Acute respiratory distress syndrome is a well-known complication in Plasmodium falciparum infection. It is less frequently described in Plasmodium vivax, and only one case is reported in Plasmodium ovale. Here we present the second description of this pulmonary complication in a P. ovale acute infection.
Health Risks in Travelers to China: The GeoSentinel Experience and Implications for the 2008 Beijing Olympics
Authors: Davis Xiaohong M. , MacDonald Susan , Borwein Sarah , Freedman David O. , Kozarsky Phyllis E. , von Sonnenburg Frank , Keystone Jay S. , Lim Poh Lian , Marano Nina , _ _
Published: September 2018

Selected data collected for travelers to China from 1998 through November 2007 by the GeoSentinel Surveillance Network were used to provide an evidence base for prioritizing recommendations for Olympic and other future travelers to China. Respiratory illness and injuries were common among patients seen during their travel; acute diarrhea and dog bites were common among those seen after travel. Tropical and parasitic diseases were rare. Pre-travel consultation for China travelers should be individualized according to these findings.
Microbiological Effectiveness and Cost of Disinfecting Water by Boiling in Semi-urban India
Authors: Clasen Thomas , McLaughlin Catherine , Nayaar Neeru , Boisson Sophie , Gupta Romesh , Desai Dolly , Shah Nimish
Published: September 2018

Despite shortcomings, boiling is the most common means of treating water at home and the benchmark against which emerging point-of-use water treatment approaches are measured. In a 5-month study, we assessed the microbiological effectiveness and cost of the practice among 218 self-reported boilers relying on unprotected water supplies. Boiling was associated with a 99% reduction in geometric mean fecal coliforms (FCs; P < 0.001). Despite high levels of fecal contamination in source water, 59.6% of stored drinking water samples from self-reported boilers met the World Health Organization standard for safe drinking water (0 FC/100mL), and 5.7% were between 1 and 10 FC/100 mL. Nevertheless, 40.4% of stored drinking water samples were positive for FCs, with 25.1% exceeding 100 FC/100 mL. The estimated monthly fuel cost for boiling was INR 43.8 (US$0.88) for households using liquid petroleum gas and INR 34.7 (US$0.69) for households using wood.
Surveillance for Adverse Drug Reactions to Combination Antimalarial Therapy with Sulfadoxine-Pyrimethamine plus Artesunate in Peru
Authors: Cairo Javier , Durand Salomón , Marquiño Wilmer , Cabezas César , Lachira Arnaldo , Quintana Fernando , Vegas Walter , Ruebush Trenton K. , Utz Gregory , Bacon David J.
Published: September 2018

In 2001, Peru changed its treatment policy for uncomplicated Plasmodium falciparum malaria on the northern Pacific Coast to sulfadoxine-pyrimethamine with atresunate (SP-AS). Because Peru was the first country in the Americas to adopt this combination therapy, we established a surveillance system in the region to assess the frequency of new or worsening symptoms after starting therapy. Over a period of two years, 1,552, or approximately two-thirds of all patients with uncomplicated P. falciparum malaria who had received SP-AS on the northern coast were followed up. Of these, 8.8% reported at least one adverse effect, with the most common being vomiting, nausea, headache, abdominal pain, dizziness, and fever; no severe adverse effects related to SP-AS therapy were identified. Treatment of uncomplicated malaria with SP-AS was associated with a low frequency of mild adverse effects in Peru, and therefore should be considered as a first-line therapy in areas of the Americas where SP efficacy is still high.
Rural Triatoma rubrovaria from Southern Brazil Harbors Trypanosoma cruzi of Lineage IIc
Authors: Martins Luciamáre P. A. , Marcili Arlei , Castanho Roberto E. P. , Therezo Altino L. S. , de Oliveira Janaína C. P. , Suzuki Rodrigo B. , Teixeira Marta M. G. , da Rosa João A. , Sperança Márcia A.
Published: September 2018

Triatoma infestans, the main vector of Chagas disease, has nearly been eliminated from Brazil. Nevertheless, other triatominae species are involved in the domiciliation process, including Triatoma rubrovaria in Rio Grande do Sul State (RS). Previous studies showed that 1.6% of the T. rubrovaria specimens collected at the rural district of Quaraí, RS, were naturally infected by Trypanosoma cruzi. In this study, five T. cruzi isolates obtained from infected triatomines were characterized molecularly and biologically. Genotyping of the T. cruzi isolates showed that they belong to lineage IIc of T. cruzi (TCIIc). Biological characterization showed miotropism and myositis during acute and chronic phases of infection, respectively. Virulence and mortality rates were variable among isolates. To our knowledge, this study corresponds to the first characterization of T. cruzi isolates from T. rubrovaria and the first description of TCIIc in the sylvatic cycle of T. cruzi from the southern region of Brazil.
Clinical Characteristics of Acute Q Fever, Scrub Typhus, and Murine Typhus with Delayed Defervescence Despite Doxycycline Treatment
Authors: Lai Chung-Hsu , Huang Chun-Kai , Weng Hui-Ching , Chung Hsing-Chun , Liang Shiou-Haur , Lin Jiun-Nong , Lin Chih-Wen , Hsu Chuan-Yuan , Lin Hsi-Hsun
Published: September 2018

Doxycycline is the recommended antibiotic for acute Q fever, scrub typhus, and murine typhus and defervescence often occurs within 3 days of treatment. Patients with delayed defervescence (> 3 days) are troublesome for clinicians. To investigate the characteristics of such patients, 18 and 88 cases with and without delayed defervescence, respectively, were studied. By univariate analysis, absence of headache (P = 0.004), jaundice (P = 0.030), icteric sclera (P = 0.030), relative bradycardia (P = 0.003), and pulmonary involvement on chest x-ray (P = 0.028) were significant findings in patients with delayed defervescence. By multivariate analysis, absence of headache (odds ratio [OR] = 8.310; 95% confidence interval [CI] = 1.990–34.706, P = 0.004), jaundice (OR = 6.242; 95% CI = 1.374–28.365, P = 0.018), and relative bradycardia (OR = 10.449; 95% CI = 2.137–51.088, P = 0.004) were the independent characteristics of patients with delayed defervescence. In treating acute Q fever, scrub typhus, and murine typhus with doxycycline, clinicians should be aware that delayed defervescence may occur in patients presenting with jaundice, relative bradycardia, and absence of headache.
SSCP Analysis of scnDNA for Genetic Profiling of Aedes aegypti
Authors: Wong Jacklyn , Tripet Frédéric , Rasgon Jason L. , Lanzaro Gregory C. , Scott Thomas W.
Published: September 2018

We characterized genetic profiling markers for Aedes aegypti using single-strand conformation polymorphism (SSCP) analysis of single copy nuclear genes (scnDNA). Nucleotide variations at 18 loci were evaluated in 173 wild Ae. aegypti collected from a single population in northwestern Thailand. We identified seven scnDNAs with polymorphisms sufficient to determine a unique genetic profile for each mosquito examined. Six markers were derived from previously mapped cDNA loci. One marker was developed from a non-coding region of a gene. The number of alleles at each scnDNA locus ranged from 3 to 9. The described scnDNAs can be used to quickly fingerprint large numbers of Ae. aegypti to track the behavior of individual mosquitoes in the field.
Genetic Insights into the Population Structure of Culex pipiens (Diptera: Culicidae) in the Northeastern United States by Using Microsatellite Analysis
Authors: Huang Shaoming , Molaei Goudarz , Andreadis Theodore G.
Published: September 2018

Members of the Culex pipiens complex are considered as biting nuisance and vectors of important arbo-viruses including West Nile virus (WNV). To analyze the genetic structure of urban and rural populations of Cx. pipiens form pipiens and gain insights into behavioral implications, mosquitoes were collected from established WNV transmission foci in Connecticut from October 2006 through October 2007, examined by using microsatellite markers, and compared with other populations from neighboring states in the northeastern United States. The mean numbers of alleles per locus for the aboveground Cx. pipiens form pipiens populations ranged from 11.5 ± 2.3 to 13.2 ± 2.4 and were not significantly different. In contrast, Cx. pipiens form molestus had greatly reduced allelic diversities with an average of 4.4 ± 1.2 alleles per locus, which was significantly lower than that of any of the Cx. pipiens form pipiens populations analyzed. We did not detect significant genetic differences between urban and rural populations of Cx. pipiens form pipiens from Connecticut nor did we observe temporal genetic changes. However, in a comparative analysis with populations of neighboring states, New Jersey, New York, and Massachusetts, genetic variations associated with geographic distance were identified. In the analyses of Bayesian clustering and principal component analysis, we identified two clusters separating Cx. pipiens form molestus from Cx. pipiens form pipiens populations, indicating that Cx. pipiens form molestus was genetically distinct from any of the Cx. pipiens form pipiens populations examined during this study.
Identifying the Reservoir Hosts of the Lyme Disease Spirochete Borrelia burgdorferi in California: The Role of the Western Gray Squirrel (Sciurus griseus)
Authors: Salkeld Daniel J. , Leonhard Sarah , Girard Yvette A. , Hahn Nina , Mun Jeomhee , Padgett Kerry A. , Lane Robert S.
Published: September 2018

We investigated the role of the western gray squirrel (Sciurus griseus) as a reservoir host of the Lyme disease spirochete Borrelia burgdorferi. A survey of 222 western gray squirrels in California showed an overall prevalence of B. burgdorferi infection of 30%, although at a county level, prevalence of infection ranged from 0% to 50% by polymerase chain reaction. Laboratory trials with wild-caught western gray squirrels indicated that squirrels were competent reservoir hosts of the Lyme disease bacterium and infected up to 86% of feeding Ixodes pacificus larvae. Infections were long-lasting (up to 14 months), which demonstrated that western gray squirrels can maintain B. burgdorferi trans-seasonally. Non-native eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) were infrequently infected with B. burgdorferi.
Presence of Enterocytozoon bieneusi Associated with Intestinal Coccidia in Patients with Chronic Diarrhea Visiting an HIV Center in Haiti
Authors: Raccurt Christian P. , Fouché Bernadette , Agnamey Patrice , Menotti Jean , Chouaki Taïeb , Totet Anne , Pape Jean W.
Published: September 2018

This study investigated the presence of Enterocytozoon bieneusi as a possible cause of chronic diarrhea in Haitian patients attending the GHESKIO AIDS clinic in Port-au-Prince, Haiti. Coccidian oocysts were found by polymerase chain reaction (PCR) in the stools of 58/74 patients with chronic diarrhea and included the following agents: 45 (60%) Cryptosporidium spp., 27 (34%) Cyclospora cayetanensis, and 11 (15%) Isospora belli. Four patients (5.5%) were co-infected with E. bieneusi and one (1.4%) had E. bieneusi alone. The PCR-restriction fragment length polymorphism (RFLP) method made it possible to document the presence in human feces of E. bieneusi in Haiti. As in sub-Saharan Africa, the association of E. bieneusi with coccidian parasites found in Haitian patients with diarrhea is probably caused by the high level of fecal contamination of soils and surface waters usually associated with countries with low hygienic standards.
Vaccinia Virus in Humans and Cattle in Southwest Region of São Paulo State, Brazil
Authors: Megid Jane , Appolinário Camila Michele , Langoni Hélio , Pituco Edviges Maristela , Okuda Liria Hiromi
Published: September 2018

A new outbreak of Vaccinia virus was observed in Southwest region of São Paulo State, Brazil. The disease was observed in four small dairy farms with manual milking. Lesions were detected in cattle and in humans previously vaccinated and not vaccinated against smallpox. Although several reports of Vaccinia virus outbreaks have been occurring in Brazil, it was not yet reported in this region. This outbreak reinforces the viral circulation in our country. The disease in persons previously vaccinated and not vaccinated against smallpox reinforces the absence of immunity, the risk to the human health, and the need for more epidemiologic and immunologic studies.
Forest Malaria in Central Vietnam
Authors: Sanh Nguyen Hong , Van Dung Nguyen , Thanh Nguyen Xuan , Trung Trieu Nguyen , Van Co Truong , Cooper Robert D.
Published: September 2018

Studies were conducted in a village in central Vietnam to explain the existence of a forest malaria cycle of transmission external to the village. The findings suggested no malaria transmission in the village because of the absence of a suitable vector, but suggested evidence for transmission in villagers when attending garden plots in the forested hills surrounding the village. A sizeable population residing near these garden plots, the presence of Anopheles dirus (a highly efficient vector), and a degree of malaria immunity within the inhabitants created suitable conditions to sustain malaria transmission outside the village.
Dengue-3 Outbreak in Paraguay: Investigations Using Capillary Blood Samples on Filter Paper
Authors: Matheus Severine , Meynard Jean-Baptiste , Lavergne Anne , Girod Romain , Moua David , Labeau Bhety , Dussart Philippe , Lacoste Vincent , Deparis Xavier
Published: September 2018

During a dengue-3 outbreak in Paraguay at the beginning of 2007, capillary blood samples absorbed onto filter papers were collected from 44 suspected cases. These samples were subjected to three molecular and serologic tests, and 31 of the 44 samples gave a positive result by at least one of the techniques used. Molecular analyses detected the dengue-3 serotype in 22 patients and additionally the dengue-2 serotype in two patients. Therefore two different serotypes were co-circulating during this outbreak. Overall, this study validates the use of dried-blood samples for field screening investigations. Indeed, all types of laboratory studies of dengue were possible with samples consisting of a few drops of dried blood from finger pricks.
Shifting Prevalence of Major Diarrheal Pathogens in Patients Seeking Hospital Care during Floods in 1998, 2004, and 2007 in Dhaka, Bangladesh
Authors: Harris Aaron M. , Chowdhury Fahima , Begum Yasmin Ara , Khan Ashraful Islam , Faruque Abu S. G. , Svennerholm Ann-Mari , Harris Jason B. , Ryan Edward T. , Cravioto Alejandro , Calderwood Stephen B. , Qadri Firdausi
Published: September 2018

Bangladesh experienced severe flooding and diarrheal epidemics in 2007. We compared flood data from 2007 with 2004 and 1998 for diarrheal patients attending the ICDDR,B hospital in Dhaka. In 2007, Vibrio cholerae O1 (33%), rotavirus (12%), and enterotoxigenic Escherichia coli (ETEC) (12%) were most prevalent. More severe dehydration was seen in 2007 compared with 2004 and 1998 (P < 0.001). In 2007, V. cholerae O1 Inaba (52%) and Ogawa (48%) were seen, whereas in 2004 and 1998 it was primarily Inaba and the Ogawa types, respectively (P < 0.001). In 2007, 51% of ETEC produced the heat labile toxin (LT) (P < 0.001 compared with 2004), 22% expressed the heat stable (ST) (P < 0.001), and 27% were ST/LT positive (P = 0.231). The CS7 colonization factor (CF) was the most prevalent in 2007 (20% compared with 6% in 2004; P = 0.05). Our findings demonstrate alterations in clinical features and phenotypic changes of major bacterial pathogens in the recent Bangladesh flood.
Post-Kala-Azar Dermal Leishmaniasis in an HIV-1–Infected Woman: Recovery after Amphotericin B Following Failure of Oral Miltefosine
Authors: Guffanti Monica , Gaiera Giovanni , Bossolasco Simona , Ceserani Norberto , Ratti Deborah , Cinque Paola , Salmaso Flavia , Gianotti Nicola , Lazzarin Adriano
Published: September 2018

We describe a case of post-kala-azar dermal leishmaniasis occurring after diagnosis of visceral leishmaniasis in an HIV-1–infected woman. The skin lesions did not recover after treatment with oral miltefosine at 100 mg/day for five cycles of 28 days but responded to treatment with liposomal amphotericin B.
Trypanosoma cruzi Transmission Cycle Among Wild and Domestic Mammals in Three Areas of Orally Transmitted Chagas Disease Outbreaks
Authors: Roque André Luiz R. , Xavier Samanta C. C. , da Rocha Marconny G. , Duarte Ana Cláudia M. , D’Andrea Paulo S. , Jansen Ana M.
Published: September 2018

We report Trypanosoma cruzi infection in wild and domestic mammals from three orally acquired Chagas disease outbreak areas in Brazil. Cachoeiro do Arari (Pará) displayed a panzootic scenery (positive mammals in all ecologic strata), and human cases were probably the consequence of their exposure within the sylvatic T. cruzi transmission cycle. In Navegantes (Santa Catarina), Didelphis spp. was the main reservoir host, given that 93% were infected. In Redenção (Ceará), Monodelphis domestica and Thrichomys laurentius were also important for parasite maintenance. TCI was present in the three studied areas. Additionally, Z3 was detected in an armadillo from Pará and TCII in a triatomine from Navegantes. Domestic animals showed a high seroprevalence and should be considered sentinels in surveillance programs. The importance of a reduction in wild mammalian fauna diversity and selection of suitable T. cruzi reservoir hosts are discussed as risk factors for the re-emergence of Chagas disease.
Polymerase Chain Reaction for Chronic Trypanosoma cruzi Infection Yields Higher Sensitivity in Blood Clot Than Buffy Coat or Whole Blood Specimens
Authors: Fitzwater Sean , Calderon Maritza , LaFuente Carlos , Galdos-Cardenas Gerson , Ferrufino Lisbeth , Verastegui Manuela , Gilman Robert H. , Bern Caryn , _ _
Published: September 2018

Trypanosoma cruzi polymerase chain reaction (PCR) is widely used, but sensitivity varies widely. We compared PCR using 121/122 primers targeting kinetoplast minicircle DNA in whole blood, buffy coat, and clot from Bolivian women. Sensitivity was significantly higher in clot (60.1%) than buffy coat (46.5%) or whole blood (40%). The use of clot could simplify specimen collection while improving sensitivity.
Beneficial Effects of Benznidazole during an Infectious-based Situation of Systemic Inflammatory Response: Cecal Ligation and Puncture
Authors: Manarin Romina , Bottasso Emanuel , Bottasso Oscar , Serra Esteban , Revelli Silvia
Published: September 2018

We have shown that benznidazole (BZL), a drug used to treat Chagas disease, markedly reduced the production of pro-inflammatory cytokines and NO-derived metabolites in experimentally Trypanosoma cruzi–infected rats. Treatment with BZL exerted beneficial effects in a model of inflammation-based pathology like murine experimental endotoxemia. Based on these findings, we wished to ascertain the effect of BZL in a closer situation to sepsis: the cecal ligation and puncture (CLP) model in C57BL/6 mice. We analyzed clinical course, survival, circulating levels of inflammation-related compounds (NO, tumor necrosis factor [TNF]-α), and bacteriemia. Recipients of BZL, 25 mg/kg, had an increased survival rate at 24 hours after CLP, showing a better clinical situation and a significant reduction of TNF-α levels and bacteriemia, with respect to the other groups. BZL failed to inhibit in vitro bacterial growth, suggesting that these effects may be partly caused by the immunomodulatory effects of BZL.
Failure of Two Distinct Anti-apoptotic Approaches to Reduce Mortality in Experimental Cerebral Malaria
Authors: Helmers Andrew J. , Lovegrove Fiona E. , Harlan John M. , Kain Kevin C. , Liles W. Conrad
Published: September 2018

Cerebral malaria is responsible for a high proportion of mortality in human Plasmodium falciparum infection. Previous studies have reported the presence of apoptosis in endothelial cells, astrocytes, neurons, and glial cells in experimental murine cerebral malaria caused by infection with Plasmodium berghei ANKA. Using this model, we tested two strategies, which have been shown to improve survival in murine models of sepsis: 1) treatment with z-VAD, a pancaspase inhibitor; and 2) overexpression of Bcl-2 using transgenic mice expressing human Bcl-2 (which prevents the release of apoptotic mediators from the mitochondria) from a myeloid cell promoter. Neither of these anti-apoptotic strategies, previously shown to provide therapeutic benefit in sepsis, improved survival in experimental cerebral malaria.
The Whole World Will Be Able to See Us: Determining the Characteristics of a Culturally Appropriate Bed Net Among Mestizo Communities of the Peruvian Amazon
Authors: Harvey Steven A. , Olórtegui Maribel Paredes , Leontsini Elli , Pezo Clara Bustamante , Pezantes Luz Marina Olórtegui , Winch Peter J.
Published: September 2018

The Peruvian Ministry of Health has distributed insecticide-treated nets (ITNs) in the country’s Amazon region since 1999. Net use is nearly universal among mestizo communities in this area, but residents traditionally use non-impregnated muslin nets. We evaluated the cultural acceptability of Ministry ITNs using qualitative methods. Our results show that nets serve various functions for users: protection against insect bites, warmth, privacy, and a sense of security for young children. Because the Ministry-distributed ITNs could not fulfill these functions as well as traditional nets, many recipients disliked or rejected the ITNs they received. Also, because the ITN fabric stains rapidly, recipients washed their nets frequently rather than waiting 6 months as recommended. We propose a two-pronged approach that balances user and health system expectations of bed nets and that should lead to more widespread and effective ITN use in the study communities.
Absence of Brain Involvement and Factors Related to Positive Serology in a Prospective Series of 61 Cases with Pulmonary Hydatid Disease
Authors: Santivañez Saul J. , Sotomayor Alfredo E. , Vasquez Julio C. , Somocurcio José G. , Rodriguez Silvia , Gonzalez Armando E. , Gilman Robert H. , Garcia Hector H. , _ _
Published: September 2018

A prospective series of 65 patients with surgically confirmed lung cystic hydatid disease was evaluated in terms of their radiologic characteristics, serologic response, and presence of cysts in other organs. Cysts were mostly single and located in lower lung lobes. Liver compromise was found in 34% of the patients. Despite a systematic search, no patient showed brain cysts in this series. Twelve patients had previous hydatid disease: six in the liver and eight in the lung (two had involvement of both organs in the past). Serology using bovine cyst fluid in an immunoblot assay was 85% sensitive. Serologic response was not associated with number or cyst or compromise of other organs but was clearly associated to the presence of at least one complicated cyst. Cyst status in terms of complications should be described to allow appropriate assessment of serologic evaluations.
Positive rK39 Serologic Assay Results in US Servicemen with Cutaneous Leishmaniasis
Authors: Hartzell Joshua D. , Aronson Naomi E. , Weina Peter J. , Howard Robin S. , Yadava Anjali , Wortmann Glenn W.
Published: September 2018

The rK39 test is a serologic assay for the rapid diagnosis of visceral leishmaniasis (VL). Serum from a North American cohort of 59 otherwise asymptomatic soldiers with cutaneous leishmaniasis (CL) was tested with the rK39 dipstick and ELISA assays, and 10.2% and 28.8% had positive results, respectively. CL is associated with a reactive rK39 assay result in some patients without clinical evidence of VL.
Optimization of Microculture and Evaluation of Miniculture for the Isolation of Leishmania Parasites from Cutaneous Lesions in Peru
Authors: Boggild Andrea K. , Miranda-Verastegui Cesar , Espinosa Diego , Arevalo Jorge , Martinez-Medina Dalila , Llanos-Cuentas Alejandro , Low Donald E.
Published: September 2018

Traditional culture of Leishmania parasites is labor-intensive and shows poor sensitivity. We evaluated microculture and novel miniculture methods for diagnosis of cutaneous leishmaniasis (CL). Consecutive patients who came to the Leishmaniasis Clinic, Hospital Nacional Cayetano Heredia, Lima, Peru, were enrolled. Lesion aspirates were cultured in traditional tubes containing Novy-MacNeal-Nicolle medium and in miniculture tubes (Eppendorf, Hamburg, Germany) and capillary tubes (microculture) containing RPMI 1640 medium containing 20% fetal bovine serum. The reference standard was positive results in two of four tests (smear, culture, polymerase chain reaction, or leishmanin skin test). Outcome measures were sensitivity and time to positivity. Fifty-five patients with 74 lesions were enrolled. Of 59 lesions that fulfilled reference criteria for CL, 50 were positive by microculture (sensitivity = 84.7%; P = 0.001), 45 by miniculture (sensitivity = 76.3%; P = 0.042), and 35 by traditional culture (sensitivity = 59.3%). Median time to positivity was three days by microculture and miniculture and five days by traditional culture (P < 0.001). Microculture and miniculture are sensitive and efficient means of diagnosing CL.