bluuebunny/crossref_metadata_2025 huggingface dataset:
A high malaria reinfection rate in children and young adults living under a low entomological inoculation rate in a periurban area of Bamako, Mali.
Authors: Sagara Issaka , SangarÃ© Djibril , Dolo Guimogo , Guindo Aldiouma , Sissoko Mamady , Sogoba Moussa , NiambÃ©lÃ© Mohamed B , YalcouÃ© Daniel , Kaslow David C , Dicko Alassane , Klion Amy D , Diallo Dapa , Miller Louis H , TourÃ© Yeya , Doumbo Ogobara
Published: May 2017

In areas of intense malaria parasite transmission, preliminary studies of the rate of reinfection after curative therapy suggest that small sample size studies of vaccine efficacy are feasible. However, the effect of transmission rate, which may vary considerably between transmission seasons, on reinfection rate has not been assessed in areas of mesoendemicity with seasonal transmission. To address this question, the Plasmodium falciparum reinfection rate after curative therapy was measured in Sotuba, a Malian village with historically low transmission rates, as estimated by the entomological inoculation rate (EIR). The reinfection rate after curative Fansidar (sulfadoxine-pyrimethamine) treatment was 80.7% (88/109). The EIR during the 13-week study period (seasonal transmission) varied between 1 and 4.5 infected bites/person/month. The finding that reinfection rates were high despite low EIRs suggests that a low EIR may be sufficient to support small sample size vaccine efficacy trials in mesoendemic areas.
Association of uterine leiomyoma and Chagas' disease.
Authors: Murta Eddie Fernando Candido , Oliveira Gustavo Paludetto , Prado Fernando De Oliveira , De Souza Maria Azniv Hazarabedian , Tavares Murta Beatriz Martins , Adad Sheila Jorge
Published: May 2017

With the aim of studying the frequency of Chagas' disease among sufferers of uterine leiomyoma, we analyzed women older than 35 years who underwent surgery and presented with leiomyoma on anatomicopathological examination. The diagnosis of Chagas infection was based on positivity to at least two of three serological tests: enzyme-linked immunosorbent assay, passive hemagglutination, and immunofluorescence. The study was case controlled, matching for age, skin color, and parity. The control group consisted of women undergoing surgery for other benign gynecological alterations. During this period, 118 women presented with uterine leiomyoma, 27.1% of whom were serologically positive for Chagas' disease versus 16.1% of the controls (P < 0.05). Matching by skin color and parity showed that 40% of the white multiparous women with uterine leiomyoma had Chagas' disease versus 10% of the controls (P < 0.05). We concluded that there appears to be an association between Chagas' disease and uterine leiomyoma.
Epidemiology of visceral leishmaniasis in the Jenin District, West Bank: 1989-1998.
Authors: Abdeen Ziad A , Sawalha Samir S , Eisenberger Carol L , Khanfar Haroun M , Greenblatt Charles L , Yousef Obaida , Schnur Lionel F , Azmi Kifaya , Warburg Alon , Bader Khaldoun A , Jaffe Charles L , Baneth Gad
Published: May 2017

Fifty patients from rural areas in the Jenin district of the West Bank, Palestinian Authority, were diagnosed with visceral leishmaniasis (VL) between 1989 and 1998. Forty-nine (98%) were younger than 6 years old, the youngest being 9 months. The yearly incident rate of VL in the Jenin district was highest in 1994 (11.8/100,000) and decreased to 1.5/100,000 in 1998; a mortality rate of 4% was recorded. Seventeen (5.5%) of 308 dogs from the Jenin and Ramallah districts of the West Bank were seropositive by enzyme-linked immunosorbent assay in a survey of canine leishmaniasis. Although all the leishmanial strains cultured from humans and dogs were identified as Leishmania infantum by a species-specific polymerase chain reaction, further genetic analysis by restriction fragment length polymorphism of kinetoplast DNA revealed patterns of polymorphism within isolates. The findings indicate that an active focus of potentially fatal VL exits in the Jenin district of the West Bank and that the parasite, vector, and reservoir host are found in this area. The epidemiology of VL in that vicinity follows the pattern of a predominantly infantile disease traditionally found in Middle Eastern countries, without a considerable involvement of immunocompromised adults infected with HIV virus as reported in other regions.
Assessment of dengue risk in relief workers in Puerto Rico after Hurricane Georges, 1998.
Authors: O'Leary Daniel R , Rigau-PÃ©rez JosÃ© G , Hayes Edward B , Vorndam A Vance , Clark Gary G , Gubler Duane J
Published: May 2017

Health risk assessment is important in the safe deployment of workers to tropical areas. We monitored dengue incidence in 204 of 222 North American relief workers visiting Puerto Rico after Hurricane Georges and during a dengue epidemic in 1998. We recorded information regarding participants' living conditions and any illness they experienced from arrival to 2 weeks after their departure. Virus isolation, polymerase chain reaction, and serological tests for anti-dengue immunoglobulin (Ig) M and IgG antibodies were used to diagnose dengue infection by means of departure and follow-up serum specimens. Among respondents, 82% (164 of 199) reported mosquito bites, 97% (156 of 161) reported having insect repellent available, and 41% (79 of 195) reported using repellent every day. Twelve participants reported a mild denguelike illness. No participants had laboratory evidence of dengue infection after 1.8 person-years of assessable exposure to areas with dengue transmission (upper 95% confidence limit of 1.67 cases per person-year). The risk of acquiring dengue among relief workers in this study appears low, possibly as a result of protective factors. Travelers to dengue-endemic areas should continue to be advised to protect themselves against mosquito bites.
Field evaluation of the ICT Malaria Pf/Pv immunochromatographic test for the detection of asymptomatic malaria in a Plasmodium falciparum/vivax endemic area in Thailand.
Authors: Coleman Russell E , Maneechai Nongnuj , Rachapaew Nattawan , Kumpitak Chalermpol , Soyseng Virat , Miller Robert S , Thimasarn Krongthong , Sattabongkot Jetsumon
Published: May 2017

Rapid antigen assays provide an effective tool for the detection of malaria in symptomatic patients. However, the efficacy of these devices for detecting asymptomatic malaria, where parasite levels are normally significantly lower than in symptomatic patients, is less well established. We evaluated the efficacy of a new combined Plasmodium falciparum-Plasmodim vivax immunochromatographic test (ICT Malaria Pf/Pv) in a cross-sectional malaria survey of the village of Ban Kong Mong Tha, Kanchanaburi Provice, Thailand, from August to December 2000. A total of 1,976 bleeds were made from 559 individuals over the course of the study. Blinded microscopy of thick and thin blood films was used as the gold standard; all discordant and 10% of concordant results were cross-checked. Of 1,976 ICT Malaria Pf/Pv dipsticks tested, 98.3% (n = 1,943) performed as expected, as evidenced by the appearance of the control line. The ICT Malaria Pf/Pv test was both sensitive (100.0%) and specific (99.7 %) for the diagnosis of falciparum malaria with parasitemias of > or = 500 trophozoites/microL; however, only 15.9% (13/82) of infected individuals had parasitemia rates this high. When P. falciparum parasitemia rates were < 500/microL, the sensitivity of the diagnosis was only 23.3%, with a positive predictive value (PPV) and a negative predictive value (NPV) of 76.2 and 97.2%, respectively. The ICT Malaria Pf/Pv test was specific, but not sensitive, for the diagnosis of vivax malaria with parasite rates of > or = 500 trophozoites/microl, with sensitivity, specificity, PPV, and NPV of 66.7%, 99.9%, 66.7%, and 99.9%, respectively. At parasite rates of < 500/microL, corresponding values were 0.0%, 99.9%, 0%, and 95.1%. Because of the relatively high cost of these assays, low parasite rates found in the majority of asymptomatic individuals, and low sensitivity of this assay with rates of < 500/microl, use of this assay as a tool for active case detection is of limited value in western Thailand.
Morphometric study of the spleen in chronic Chagas' disease.
Authors: Pereira SanÃ­via Aparecida de Lima , Rodrigues Denise B Rocha , Castro Eumenia Costa da Cunha , dos Reis Marlene Antonia , Teixeira Vicente de Paula Antunes
Published: May 2017

There is frequently an increase in spleen size in infectious systemic and chronic venous congestion. The aim of this report was to perform a comparative study of the spleen tissue of chagasic or nonchagasic autopsied patients with or without congestive heart failure. Evaluations were made of 111 cases. Connective tissue intensity, follicular density and area, and follicular arterioles wall area were determined through the morphometric study. The connective tissue was similar in all groups. The density of the lymphoid follicles was significantly less among the chagasic cases (P = 0.032). The follicular area was larger among the chagasic cases and in the chagasic group with congestive heart failure. The chagasic group without congestive heart failure presented a greater area of follicular arteriole walls. Therefore, the spleen modifications in chronic Chagas' disease could be a consequence not only of the heart failure but also of the Chagas infection itself.
Simple dipstick assay for the detection of Salmonella typhi-specific IgM antibodies and the evolution of the immune response in patients with typhoid fever.
Authors: Hatta Mochammad , Goris Marga G A , Heerkens Evy , Gooskens Jairo , Smits Henk L
Published: May 2017

Application of a dipstick assay for the detection of Salmonella typhi-specific IgM antibodies on samples collected from S. typhi or S. paratyphi culture-positive patients at the day of admission to the hospital revealed the presence of specific IgM antibodies in 43.5%, 92.9%, and 100% for samples collected 4-6 days, 6-9 days, and > 9 days after the onset of fever, respectively. The mean sensitivity for samples collected an average of 6.6 days after the onset of fever was 65.3%. Culture was positive in 65.9% of the cases with a final clinical diagnosis of typhoid fever. Testing of paired serum samples from culture negative patients with a final clinical diagnosis of typhoid fever resulted in staining of the dipstick in 4.3% of the samples collected at the day of admission to the hospital and in 76.6% of the samples collected one week later, thereby provided strong supporting evidence of typhoid fever by demonstrating seroconversion in a large proportion of the patients. The dipstick assay may thus also be useful for the serodiagnosis of culture-negative patients with clinical signs and symptoms consistent with typhoid fever. The advantages of the dipstick assay are that the result can be obtained on the same day allowing a prompt treatment, that only a small volume of serum is needed, and that no special laboratory equipment is needed to perform the assay. The stability of the reagents of the dipstick and the simplicity of the assay allows its use in places that lack laboratory facilities.
Isolation of eastern equine encephalitis virus and West Nile virus from crows during increased arbovirus surveillance in Connecticut, 2000.
Authors: Beckwith William H , Sirpenski Stanley , French Richard A , Nelson Randall , Mayo Donald
Published: May 2017

The emergence of the West Nile virus (WNV) in the northeastern United States has drawn emphasis to the need for expanded arbovirus surveillance in Connecticut. Although the state of Connecticut began a comprehensive mosquito-screening program in 1997, only since 1999 have there been efforts to determine the prevalence of arboviruses in bird populations in this state. Herein, we report on our results of an arbovirus survey of 1,704 bird brains. Included in this report are the first known isolations of eastern equine encephalitis virus (EEEV) from crows and data on the geographic and temporal distribution of 1,092 WNV isolations from crow species. Moreover, these nine isolations of EEEV identify regions of Connecticut where the virus is rarely found. With the exception of WNV and EEEV, no other arboviruses were isolated or detected. Taken together, these data illustrate the distribution of avian borne EEEV and WNV in 2000 and support the need for ongoing avian arbovirus surveillance in Connecticut.
Circulating parasite antigen in patients with hydrocephalus secondary to neurocysticercosis.
Authors: Garcia H H , Gonzalez A E , Gilman R H , Bernal T , Rodriguez S , Pretell E J , Azcurra O , Parkhouse R M E , Tsang V C W , Harrison L J S , _ _
Published: May 2017

End stages of neurocysticercosis include residual intraparenchymal brain calcifications and hydrocephalus. Although brain calcifications alone have a benign prognosis, hydrocephalus is frequently associated with chronic inflammation and intracranial hypertension, together with a protracted clinical evolution, and may lead to patient deaths. By using a monoclonal-based antigen detection enzyme-linked immunosorbent assay, we measured the levels of circulating parasite antigen in the sera of 56 patients with neurocysticercosis: 27 with calcifications only and 29 with hydrocephalus. The assay gave positive results in 14 of 29 patients with hydrocephalus but was consistently negative in patients with calcifications. Circulating parasite antigen in hydrocephalus secondary to neurocysticercosis indicates the presence of live parasites in these patients and thus a potential benefit from antiparasitic therapy.
Platelet adhesion to dengue-2 virus-infected endothelial cells.
Authors: Krishnamurti Chitra , Peat Raquel A , Cutting Mary A , Rothwell Stephen W
Published: May 2017

Platelets in circulation normally do not adhere to resting endothelial cells. However, in response to vascular injury they adhere to stimulated endothelium and thereby play an essential role in hemostasis and thrombosis. Infection with dengue-2 virus can cause illness accompanied by thrombocytopenia and hemorrhage. Increased adherence of platelets to stimulated endothelial cells could contribute to the thrombocytopenia. In this study, adherence of radioisotopically labeled platelets to 1) unstimulated, 2) lipopolysaccharide (LPS)-stimulated, and 3) dengue-2 virus-infected human umbilical vein endothelial cells (HUVEC) was measured in an in vitro assay. Primary HUVEC were cultured in 96-well tissue culture plates in the presence or absence of LPS or dengue-2 virus. These cells were co-incubated with 3H-adenine-labeled fresh platelets for 30 min after which the cells were assayed for adherent platelets. Within 30 min there was maximum adherence of platelets to confluent LPS-stimulated HUVEC (36 +/- 4% over controls; P = 0.005). In comparison, there was a significant increase in adherence to dengue-2 infected HUVEC (78 +/- 7%; P < or = 0.001). Additionally, platelet adherence was visualized using fluorescent microscopy. Dengue-2 infection stimulated the HUVEC as monitored by expression of E-selectin. Platelets that adhered to dengue-2 or LPS-stimulated HUVEC were activated as visualized by dual fluorescent probes. These data demonstrate that human platelets adhere to dengue-2 virus-stimulated HUVEC and this interaction could contribute to the thrombocytopenia observed during infection.
Clinical and laboratory predictors of imported malaria in an outpatient setting: an aid to medical decision making in returning travelers with fever.
Authors: D'Acremont ValÃ©rie , Landry Pierre , Mueller Ivo , PÃ©coud Alain , Genton Blaise
Published: May 2017

No evidence-based information exists to guide clinicians for giving presumptive treatment to returning travelers when malaria is strongly suspected on clinical grounds but laboratory confirmation is not immediately available or is negative. A prospective study was conducted in travelers or migrants who sought care for fever to identify clinical and laboratory predictors of Plasmodium parasitemia. A total of 336 questionnaires were collected (97 malaria case patients and 239 controls). Multivariate regression analysis showed inadequate prophylaxis, sweating, no abdominal pain, temperature > or = 38 degrees C, poor general health, enlarged spleen, leucocytes < or = 10 x 10(3)/L, platelets < 150 x 10(3)/L, hemoglobin < 12 g/dL, and eosinophils < or = 5% to be associated with parasitemia. Enlarged spleen had the highest positive likelihood ratio for a diagnosis of malaria (13.6), followed by thrombopenia (11.0). Posttest probabilities for malaria were 85% with enlarged spleen and 82% with thrombopenia. A rapid assessment can thus help to decide whether a presumptive treatment should be given or not, especially when the results of the parasitological examination are not immediately available or are uncertain.
A retrospective examination of sporozoite-induced and trophozoite-induced infections with Plasmodium ovale: development of parasitologic and clinical immunity during primary infection.
Authors: Collins William E , Jeffery Geoffrey M
Published: May 2017

A retrospective analysis was made of clinical and parasitologic parameters in patients with induced Plasmodium ovale infection to document the initial clinical and parasitologic response and their subsequent development of clinical and parasitologic immunity, and to determine the effect of previous homologous and heterologous malaria on subsequent infection with this parasite. The prepatent periods were relatively uniform. Eight patients injected with sporozoites that had been stored frozen had a median prepatent period of 14 days (range = 14-20 days). Thirty-five patients infected via the bites of infected mosquitoes had a median prepatent period of 15 days (range = 12-18 days). In eight patients previously infected with P. vivax, the median prepatent period was 16 days. High-intensity fever (> or = 104 degrees F) was frequently seen, with instances of fever > or = 106 degrees F recorded on many occasions. Fever > 101 degrees F and > 104 degrees F occurred for much shorter periods of time than had been observed in patients infected with P. falciparum. Parasite counts > 10,000/microL were infrequent; in most patients, such parasite counts rarely lasted more than two or three days. Gametocytemia was generally of low density and lasted only a few days. The overall length of the clinical and parasitologic period was much shorter compared with that seen in patients infected with P. falciparum. Previous infection with P. ovale did not prevent reinfection, but resulted in reduced levels of parasitemia and fever. Previous infection with heterologous species of Plasmodium did not prevent infection; some reduction in the frequency and intensity of fever and parasite counts was evident. Previous infection with homologous or heterologous parasites failed to eliminate the production of infective gametocytes. A total of 462 lots of mosquitoes were fed on 67 patients with no previous history of infection. Of these feedings, 168 (36.4%) resulted in infection as determined by the presence of oocysts on the midguts of dissected mosquitoes. As shown, the infection rate increased with the density of gametocytes even though 48 (23.4%) of 205 lots of mosquitoes fed when no gametocytes were detected were infected.
Identification of virulence-associated antigens and plasmids in Rhodococcus equi from patients with acquired immune deficiency syndrome and prevalence of virulent R. equi in soil collected from domestic animal farms in Chiang Mai, Thailand.
Authors: Takai Shinji , Tharavichitkul Prasit , Sasaki Chie , Onishi Yoko , Yamano Shigeki , Kakuda Tsutomu , Tsubaki Shiro , Trinarong Chumnan , Rojanasthien Suvichai , Sirimalaisuwan Anucha , Tesaprateep Ted , Maneekarn Niwat , Sirisanthana Thira , Kirikae Teruo
Published: May 2017

The prevalence of virulent Rhodococcus equi in soil collected from 17 domestic animal farms (from 12 cattle, 1 pig, and 4 horse farms) and in 6 clinical specimens from patients with acquired immune deficiency syndrome (AIDS) in Chiang Mai, Thailand, was investigated. The isolates were tested for the presence of 15-17-kDa antigens (VapA) and a 20-kDa antigen (VapB) by immunoblotting and for the presence of virulence plasmid DNA. Rhodococcus equi was isolated from most soil samples (68 of 80) obtained from the 17 farms, with 2.0 x 10(2) to 6.0 x 10(5) colony-forming units per gram of soil. We detected VapA in none of the 537 isolates from the soil samples. In one isolate from a pig farm, both VapB and virulence plasmid DNA were detected. Of the 6 clinical isolates from patients with AIDS, however, 4 isolates contained both VapB and virulence plasmid DNA. The remaining 2 isolates were avirulent.
An OspA-based genospecies identification of Lyme disease spirochetes (Borrelia burgdorferi) isolated in Taiwan.
Authors: Shih Chien-Ming , Chao Li-Lian
Published: May 2017

To further identify the genospecies of Lyme disease spirochetes (Borrelia burgdorferi) isolated in Taiwan, we analyzed the genomic identities of these Taiwan isolates (TWKM1-7) by genospecies-specific polymerase chain reaction (PCR) assay, restriction fragment length polymorphism (RFLP) analysis, and gene sequencing based on the OspA gene sequences of B. burgdorferi sensu lato. PCR analysis indicates that all of these Taiwan isolates were genetically related to the genospecies of B. burgdorferi sensu stricto by their differential reactivities with genospecies-specific PCR primers. After cleavage by DraI, three different RFLP patterns in relation to three different genospecies of Lyme disease spirochetes were observed, and all of these Taiwan isolates were affiliated with the genospecies of B. burgdorferi sensu stricto. The phylogenetic analysis also reveals that the sequence similarity of PCR-amplified OspA gene of these Taiwan isolates is highly homogeneous, with a homogeneity of more than 99.8% within the genospecies of B. burgdorferi sensu stricto. These results confirm that the genomic identities of these Taiwan isolates belong to the genospecies of B. burgdorferi sensu stricto.
Age-specific prevalence of antibodies to hepatitis A in Santiago, Chile: risk factors and shift in age of infection among children and young adults.
Authors: Fix Alan D , Martin Oriana San , Gallicchio Lisa , Vial Pablo A , Lagos Rosanna
Published: May 2017

Transition from high to lower endemicity of hepatitis A virus (HAV) infection may portend increased public health burden with the shift of infection to older ages and increasing morbidity and mortality. This report describes age-specific prevalence of antibodies to HAV (anti-HAV) among children and young adults in Santiago, Chile, compared with previous prevalence data and assesses factors predictive for anti-HAV. In 1998, a serosurvey was performed in Metropolitan Santiago, designed to enroll a representative, age-stratified population on the basis of area of residence. A total of 784 individuals (age range, 1-24 years) were enrolled. Anti-HAV prevalence by year of life was as follows: ages 1 to 4, 12.5%; 5 to 9, 26.2%; 10 to 14, 43.4%; 15 to 19, 57.4%; 20 to 24, 73.9%. Adjusting for age, factors associated (inversely) with anti-HAV included residential areas of higher socioeconomic status (SES), parental education, and household characteristics of potable water, municipal sewage system, and the presence of a toilet or refrigerator in the house. In logistic regression analysis, only maternal years of education and residence in areas of higher SES remained independently associated with anti-HAV. Excluding those from higher SES areas, comparison of the age-specific anti-HAV prevalence data from previous studies of similar methodology in areas of lower SES revealed consistent decreases across all age groups; the age-standardized prevalence for this age range (1-24 years) dropped from 53.7% in 1990 to 40.6% in 1998. In light of the growing pool of susceptible individuals at older ages, with HAV continuing to circulate in the communities, evaluation of the feasibility of vaccination programs would be judicious.
Assessing the Parasight-F test in northeastern Papua, Indonesia, an area of mixed Plasmodium falciparum and Plasmodium vivax transmission.
Authors: Taylor Walter R J , Widjaja Hendra , Basri Hasan , Fryauff David J , Ohrt Colin , Taufik  , Tjitra Emiliana , Hoffman Stephen L , Baso Samuel , Richie Thomas L
Published: May 2017

User-friendly, reliable, and inexpensive methods for diagnosing malaria are needed at the primary health care level. During a randomized treatment trial, the Parasight-F test was assessed on days 0, 3, 7, and 28 against standard light microscopy of Giemsa-stained thick blood smears for diagnosing Plasmodium falciparum parasitemia in patients with P. falciparum (n = 84) or P. vivax (n = 59) malaria. The median P. falciparum parasite count on day 0 was 2,373/microL (range = 20-74,432/microL). At the start of treatment, the Parasight-F test had a sensitivity of 95.2% (80 of 84; 95% confidence interval [CI] = 88.2-98.7), and a specificity of 94.9% (56 of 59; 95% CI = 85.8-98.9). On day 7, this test showed false-positive results in 17 (16.3%) of 104 patients (95% CI = 9.8-24.9). The Parasight-F test performed well when compared with light microscopy in detecting P. falciparum parasitemia in patients presenting with clinical malaria. However, the high false-positive rate on day 7 limits its use for patient follow-up.
Molecular epidemiology of malaria in Cameroon. X. Evaluation of PFMDR1 mutations as genetic markers for resistance to amino alcohols and artemisinin derivatives.
Authors: Basco Leonardo K , Ringwald Pascal
Published: May 2017

Mutations at five positions in the Plasmodium falciparum multidrug-resistance gene 1 (pfmdr1), initially thought to confer resistance to chloroquine, have been associated with in vitro resistance to amino alcohols and artemisinin derivatives in more recent studies. To assess the possible association between drug resistance phenotype and pfmdrl polymorphisms and establish the baseline pfmdr1 sequence data in YaoundÃ©, Cameroon, the in vitro drug sensitivity pattern was determined for 64 clinical isolates by isotopic microtest. The pfmdr1 alleles were determined by a polymerase chain reaction and automatic sequencing. A large majority of isolates carried Tyr-86 (88%) and Phe-184 (91%) alleles. With the exception of one isolate with mixed codon 1246, all isolates had wild-type alleles Ser-1034, Asn-1042, and Asp-1246. There was no statistical association between codons 86 and 184 and in vitro response to chloroquine, amino alcohols, and artemisinin derivatives (P > 0.05). Our data do not seem to support the hypothesis that mutations in codons 86 and 184 influence the in vitro response to these drugs. Further monitoring of both in vitro response and pfmdrl polymorphisms is required to evaluate the potential role played by other pfmdr1 alleles in the determination of drug resistance in Africa.
Hepatitis e virus infection in fulminant hepatitis patients and an apparently healthy population in Bangladesh.
Authors: Sheikh Aleemuzzaman , Sugitani Masahiko , Kinukawa Noriko , Moriyama Mitsuhiko , Arakawa Yasuyuki , Komiyama Kazuo , Li Tian-Cheng , Takeda Naokazu , Ishaque Shamsuddin M , Hasan Mahmud , Suzuki Koyu
Published: May 2017

This is the first study comparing hepatitis E virus (HEV) infection in Bangladesh in fulminant hepatitis (FH) patients presumed to have a viral cause and in the apparently healthy population. Sera from 22 FH patients were analyzed for antibodies to hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C and D viruses, and HEV and for hepatitis B surface antigen (HBsAg). Anti-HEV immunoglobulin M (IgM) was detected in the sera of 63.6% of patients, whereas 35.7% were positive for HBsAg. A high prevalence of HEV infection (83.3%) was noted in the HBV carriers. Serum samples from 273 apparently healthy individuals were tested for antibodies to HAV and HEV. Anti-HEV IgM was detected in 7.3% of the samples. The seroprevalence of HAV differed from that of HEV in the same population because all samples were negative for anti-HAV IgM. These data indicate that HEV infection is highly endemic in Bangladesh.
Evaluation of two enzyme-linked immunosorbent assay methods for detection of immunoglobulin M antibodies in acute leptospirosis.
Authors: Levett Paul N , Branch Songee L
Published: May 2017

Leptospirosis is a common zoonosis of worldwide distribution. Diagnosis of leptospirosis is usually accomplished by serology, but the microscopic agglutination test (MAT) generally requires paired sera for detection of seroconversion and is considered too complex for routine use. A number of rapid assays have been developed in recent years. In the present study, 2 immunoglobulin (Ig) M enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the early diagnosis of acute leptospirosis in Barbados. A total of 103 patients admitted to the Queen Elizabeth Hospital for diagnosis of suspected leptospirosis were investigated. A case of leptospirosis was confirmed by a 4-fold rise in titer between 2 sera tested by MAT, an initial titer of > or = 800 in the MAT, or by isolation of leptospires from blood or urine. A total of 48 cases of leptospirosis were confirmed. In 33 cases, both commercial assays were positive in the first sample, taken at admission, a mean of 6.7 days after onset of symptoms, whereas seroconversion was detected in a further 9 cases. Both assays were negative in 5 cases, and the remaining case gave discordant results in the 2 assays. False-positive IgM results were detected in 4 patients without leptospirosis. The sensitivity of the 2 assays was 89.6 and 97.5%, respectively, and specificities were 92.7 and 96.4%, respectively. The positive predictive values were 87.8 and 95.5%, and the negative predictive values were 90.7 and 89.5%, respectively. Either of these assays can be used for early diagnosis of leptospirosis, particularly in laboratories that cannot perform more specialized leptospiral serology.
The epidemiology of tick-borne relapsing fever in the United States.
Authors: Dworkin Mark S , Shoemaker Phyllis C , Fritz Curtis L , Dowell Mark E , Anderson Donald E
Published: May 2017

Each year, many residents of and visitors to endemic regions of the western United States are exposed to the vector of tick-borne relapsing fever (TBRF), an underrecognized and underreported disease. Through review of report forms and literature review, we identified 450 cases of TBRF acquired in the United States in 11 western states (and in British Columbia by a U.S. resident) from January 1977 to January 2000. Exposure sites were in forested areas, at varying elevations, in mountainous regions (Cascade, Rocky Mountain, San Bernardino, and Sierra Nevada ranges) of the United States and Canada and in limestone caves in central Texas. Only 13 counties accounted for approximately 50% of all cases. Forty percent of the cases were not residents of the state where TBRF exposure occurred, including 7% from 11 states where TBRF is not endemic. TBRF is endemic in the United States and is a disease affecting travelers, who may return home with the disease to areas where physicians are not familiar with it.
Short report: increased level of serum nitric oxide in patients with dengue.
Authors: Valero Nereida , Espina Luz M , AÃ±ez German , Torres Enrique , Mosquera JesÃºs A
Published: May 2017

Nitric oxide (NO) has been involved in several infectious diseases. Virus dengue is capable of inducing increased levels of NO when cocultured with human Kupffer and spleen cells. However, no reports describe the levels of NO in patients with dengue infection. Increased levels of NO were found in patients with the classic form of the disease; however, in the hemorrhagic form of the disease, similar levels to those of healthy controls were found. In vitro studies showed no increased levels of NO when human platelets were incubated with the virus. Increased NO in classical dengue could be important in the evolution from the nonhemorrhagic to the hemorrhagic forms of dengue.
Epidemiology of dengue in Sri Lanka before and after the emergence of epidemic dengue hemorrhagic fever.
Authors: Messer William B , Vitarana U Tissa , Sivananthan Kamalanayani , Elvtigala Jayanthi , Preethimala L D , Ramesh R , Withana Nalini , Gubler Duane J , De Silva Aravinda M
Published: May 2017

Before 1989, dengue epidemiology in Sri Lanka was characterized by frequent transmission of all four dengue serotypes but a low incidence of dengue hemorrhagic fever (DHF). After 1989, cases of DHF dramatically increased. Here we present the results of epidemiologic studies conducted in Colombo, Sri Lanka before and after epidemic emergence of DHF in 1989. We compared the proportion of dengue cases among people with fever attending clinics from 1980 to 1984 and in 1997 and 1998 to determine if an increase in dengue transmission was associated with more DHF cases being reported. We also compared the relative distribution of dengue virus serotypes circulating in Colombo before and after the emergence of DHF. We detected no significant differences in dengue as a proportion of fever cases or in serotype distribution between the pre and post-DHF periods. We conclude that an increase in virus transmission or a change in circulating serotypes does not explain the epidemic emergence of DHF in Sri Lanka.
Survival and growth of Shigella flexneri, Salmonella enterica serovar enteritidis, and Vibrio cholerae O1 in reconstituted infant formula.
Authors: Wu Fone Mao , Beuchat Larry R , Doyle Michael P , Mintz Eric D , Wells Joy G , Swaminathan Balasubr
Published: May 2017

Formula feeding is an alternative method to prevent mother-to-child infection with human immunodeficiency virus through breast-feeding in developing countries. Growth of bacterial pathogens in reconstituted infant formula has become a health hazard when contaminated water is used for rehydration. This study was conducted to assess bacterial safety risk of using contaminated water to reconstitute infant formula. Survival and growth characteristics were determined for three bacterial pathogens, Vibrio cholerae O1, Shigella flexneri, and Salmonella enterica serovar Enteritidis, inoculated into sterile tap water (3.2-3.4 log10 colony-forming units [CFU]/ml) and infant formula (1.5-1.7 and 3.2-3.4 log10 CFU/ml) and incubated at 4 degrees C or 30 degrees C for up to 24 hours. Vibrio cholerae O1 was the most sensitive of the three pathogens when inoculated into water, with no viable cells detected within 2 hours at 4 degrees C or 30 degrees C. The rate of inactivation in water was greater at 30 degrees C than at 4 degrees C. Vibrio cholerae O1, Shigella flexneri, and Salmonella enterica serovar Enteritidis grew rapidly in infant formula at 30 degrees C, reaching populations of 9.2, 8.7, and 9.2 log10 CFU/ml, respectively, at 24 hours. Populations of all three pathogens did not change significantly after incubating infant formula for 24 hours at 4 degrees C, but continuously decreased in water throughout incubation for 24 hours, regardless of temperature. Results suggest that unless refrigerated, reconstituted infant formula should be consumed soon after preparation to avoid increased risk of illness associated with increases in populations of pathogenic bacteria that may be introduced by contaminated water.
Natural host relationships and genetic diversity of Whitewater Arroyo virus in southern Texas.
Authors: Fulhorst Charles F , Milazzo Mary Louise , Carroll Darin S , Charrel Remi N , Bradley Robert D
Published: May 2017

The purpose of this study was to refine our knowledge of the natural host relationships of Whitewater Arroyo (WWA) virus. Two hundred eight rodents, representing nine species, were captured in July 1999 on the Chaparral Wildlife Management Area in southern Texas and tested for evidence of arenavirus infection. Antibody to an arenavirus was found in seven (21.9%) of 32 southern plains woodrats (Neotoma micropus) and none of 168 other rodents. Infectious WWA virus was isolated from four antibody-positive southern plains woodrats, one of 25 antibody-negative southern plains woodrats, and none of 176 other rodents. Collectively, the results indicate that the southern plains woodrat is a principal host of WWA virus in southern Texas. Analyses of viral gene sequence data revealed substantial genetic diversity among WWA virus strains isolated from the woodrats, suggesting that multiple variants of the virus can coexist in a single woodrat species in a small geographic area.
Serologic survey of cattle in the northeastern and north central United States, Virginia, Alaska, and Hawaii for antibodies to Cache Valley and antigenically related viruses (Bunyamwera serogroup virus).
Authors: Sahu Sudhir P , Pedersen Douglas D , Ridpath Harold D , Ostlund Eileen N , Schmitt Beverly J , Alstad David A
Published: May 2017

Bovine sera from northeastern states (Connecticut, Delaware, Maine, Maryland, Massachusetts, New York, Pennsylvania, Vermont, and West Virginia), north central states (Indiana, Illinois, Iowa, Kentucky, Michigan, Minnesota, North Dakota, Ohio, South Dakota, and Wisconsin), Virginia, Alaska, and Hawaii were examined for the presence of neutralizing antibodies to Cache Valley (CV), Lokern (LK), Main Drain (MD), Northway (NW), and Tensaw (TS) viruses. Microneutralization tests were performed using Vero cells. Ninety percent inhibition of the virus at a 1:10 serum dilution was considered positive for the presence of specific antibody. Sera having antibody to more than one virus were titrated from 1:10 to 1:640. The results indicated that 4-28% of the cattle per region had specific antibodies to CV virus. Neutralizing antibodies to NW, LK, and TS viruses were also detected, indicating possible exposure to these Bunyamwera serogroup viruses along with CV virus. Antibody titers measured against NW virus were very similar to those against CV virus. Antibodies to MD virus were present in low levels in bovine sera from Illinois, Maryland, and Ohio. Cattle from Alaska had only antibodies to NW virus. Antibodies to Bunyamwera serogroup viruses were not observed in sera from Hawaii.
Polymerase chain reaction-based diagnosis of Mediterranean spotted fever in serum and tissue samples.
Authors: Leitner Moshe , Yitzhaki Shmuel , Rzotkiewicz Sabine , Keysary Avi
Published: May 2017

A nested polymerase chain reaction (PCR) assay has been developed and used in the diagnosis of fatal and benign cases of Mediterranean spotted fever (MSF). The test was based on specific primers derived from a Rickettsia conorii 17-kD protein gene. A positive signal was obtained from spotted fever group (SFG) and typhus group (TG) rickettsiae. Discrimination between SFG and TG rickettsiae was based on a restriction fragment length polymorphism test. Other gram-negative bacterial species tested did not generate a signal, attesting for the specificity of the assay. The SFG-specific DNA fragment was detected in four of 29 acute-phase sera from serologically confirmed patients with MSF, while acute-phase sera from 25 patients without MSF were PCR negative. Acute-phase sera samples (five of five) and tissue autopsies (six of seven) from fatal suspected cases of MSF were PCR positive. The results demonstrate that sera and tissue samples are suitable specimens for the nested PCR tests, especially in fatal cases.
Prevalence of antibody to Chlamydia pneumoniae in residents of Japan, the Solomon Islands, and Nepal.
Authors: Shimizu Chie , Nabeshima Shigeki , Kikuchi Kensuke , Furusyo Norihiro , Kashiwagi Seizaburo , Hayashi Jun
Published: May 2017

Sera of 4,050 residents from Japan, 276 from the Solomon Islands, and 602 from Nepal were tested by an enzyme-linked immunosorbent assay to determine the prevalence of antibody to Chlamydia pneumoniae. The prevalence of IgG and IgA antibodies was significantly higher in the Solomon Islands (64.9% and 82.2%) and Nepal (73.1%, and 69.8%) than in Japan (53.6% and 41.1%). These prevalence rates increased throughout the teenage years in the Solomon Islands and Japan and leveled off with age, whereas in Nepal the prevalence rates gradually increased with age. The prevalence of a high (> 3.0) IgA antibody index, which is suggestive of acute infection, was significantly higher in the Solomon Islands (34.8%) than in Japan (3.2%) and Nepal (10.5%). The prevalence of IgG antibody ranged from 46.4% to 67.7%, and the prevalence of IgA antibody ranged from 33.7% to 61.8% in the four difference areas of Japan. These findings indicate considerable differences in the prevalence of antibodies to C. pneumoniae by age in these nations and between the regions of Japan tested.
Inhibition of intracellular proliferation of Leishmania parasites in vitro and suppression of skin lesion development in BALB/c mice by a novel lipid A analog (ONO-4007).
Authors: Khan Mohammed A K , Maruno Motoyoshi , Khaskhely Noor M , Ramzi Saeef T , Hosokawa Atsushi , Uezato Hiroshi , Landires Eduardo A Gomez , Hashiguchi Yoshihisa , Nonaka Shigeo
Published: May 2017

A synthetic lipid A analog (ONO-4007) exhibits antileishmanial activity by activating Leishmania-infected macrophages in experimental leishmaniasis. In the present in vitro study, ONO-4007 at concentrations between 0.01 and 1.00 mg/mL markedly inhibited the proliferation of Leishmania major and L. amazonensis promastigotes. Ultrastructurally, L. major-infected macrophages showed degenerated intracellular amastigotes after exposure to ONO-4007. Leishmania-infected macrophages treated with ONO-4007 showed poorly developed parasitophorous vacuoles. High levels of tumor necrosis factor-alpha were induced by ONO-4007 in Leishmania-infected macrophages. In this in vivo study, L. amazonensis-infected BALB/c mice were treated with a dose of 30 mg/kg of ONO-4007 by perilesional and peritoneal injections. The skin lesion size was assessed before treatment with ONO-4007 and at eight weeks after injection. The lesion size was significantly suppressed in mice perilesionally injected with ONO-4007 (P < 0.01) compared with the controls. The data from our present in vitro and in vivo studies indicate that ONO-4007 has an antileishmanial effect.
Detection of mutations in the Plasmodium falciparum dihydrofolate reductase (dhfr) gene by dot-blot hybridization.
Authors: Abdel-Muhsin Abdel-Muhsin A , Ranford-Cartwright Lisa C , Medani Abdel-Rahman , Ahmed Salah , Suleiman Suad , Khan Baldip , Hunt Paul , Walliker David , Babiker Hamza A
Published: May 2017

There is a need for a specific, sensitive, robust, and large-scale method for diagnosis of drug resistance genes in natural Plasmodium falciparum infections. Established polymerase chain reaction (PCR)-based methods may be compromised by the multiplicity of P. falciparum genotypes in natural infections. Here we adopt a dot-blot method to detect point mutations at nucleotide 323 (residue 108) in the P. falciparum dihydrofolate reductase (dhfr) gene using allele-specific oligonucleotide probes. Serine (Ser) or threonine (Thr) at this position are associated with sensitivity to pyrimethamine while asparagine (Asn) is associated with resistance. The method combines PCR amplification and hybridization of amplified products with radiolabeled allele-specific probes. This technique is specific and sensitive; it detects parasitemia of less than 100 parasites/microl of blood, and can identify a minority parasite genotype down to 1% in a mixture. Analysis of P. falciparum isolates from Sudan, of known response to pyrimethamine, has demonstrated the sensitivity and specificity of the method and its ability to detect multiple genotypes in single infections. Furthermore, it has confirmed the association between pyrimethamine responses and dhfr alleles. The method has been successfully extended for analysis of other point mutations in dhfr at residues 51 and 59, which are associated with a high level of pyrimethamine resistance.
Lymphatic filariasis elimination and schistosomiasis control in combination with onchocerciasis control in Nigeria.
Authors: Hopkins Donald R , Eigege Abel , Miri Emmanuel S , Gontor Ibrahim , Ogah Gladys , Umaru John , Gwomkudu Chuwang C , Mathai Wanjira , Jinadu My , Amadiegwu Stanley , Oyenekan O Kehinde , Korve Kenneth , Richards Frank O
Published: May 2017

This paper describes a pilot initiative to incorporate lymphatic filariasis (LF) elimination and urinary schistosomiasis (SH) control into a mature onchocerciasis control program based on community-directed ivermectin treatment in central Nigeria. In the same districts having onchocerciasis we found LF (as determined by blood antigen testing in adult males) in 90% of 149 villages with a mean prevalence of 22.4% (range 0-67%). Similarly, SH, as determined by dipstick reagent testing for blood in urine from school children, was found in 91% of 176 villages with a mean orevalence in school age children of 24.4% (range 0-87%). Health education and treatment interventions for SH resulted in 52,480 cumulative praziquantel treatments, and 159,555 combined onchocerciasis and LF treatments (with ivermectin and albendazole) as of the end of 2000. Treatments for onchocerciasis and LF were separated by at least 1 week from treatments for SH. There was no negative impact on the coverage of the onchocerciasis program by the addition of LF and SH activities.
Activity of azithromycin against Leishmania major in vitro and in vivo.
Authors: Krolewiecki Alejandro , Leon Shalom , Scott Phillip , Abraham David
Published: May 2017

Azithromycin, an azalide antibiotic of the macrolide family, concentrates in the tissues and especially in macrophages. Because Leishmania parasites reside in these cells, we tested this antibiotic for a possible antileishmanial activity in vitro and in vivo. Azithromycin decreased the Leishmania major promastigote count in cell-free cultures at log phase approximately 50-fold. In macrophage cultures infected with L. major amastigotes, azithromycin caused a significant decrease in parasite levels with an ED50 of 12 microg/ml. The activity in vivo was evaluated after infection of the footpads of susceptible BALB/cByJ mice and resistant C57BL/6J mice with L. major. Treatment of BALB/cByJ mice with azithromycin, 100 to 200 mg/kg/d, resulted in a significant decrease in lesion size and in the number of parasites per lesion, whereas no effect was seen in the treated C57BL/6J mice. Azithromycin has activity against L. major in vitro and in vivo. Given the severity of the disease and the limitations of the available therapeutic agents, azithromycin may have a significant role in the treatment of this group of diseases.
Multiple cerebral infarctions following a snakebite by Bothrops caribbaeus.
Authors: Numeric Patrick , Moravie Victor , Didier Martin , Chatot-Henry Didier , Cirille Sylvia , Bucher Bernard , Thomas Laurent
Published: May 2017

Bothrops caribbaeus, a species of the Bothrops complex, is found only in the island of Saint Lucia, West Indies. Snakebite from this pitviper is very rare. We report the case of a healthy 32-year-old Saint Lucian man who developed multiple cerebral infarctions following envenoming by this snake. This patient developed signs and symptoms very similar to those observed in patients envenomed by Bothrops lanceolatus, a snake found only in Martinique, the neighbor island of Saint Lucia. This clinical presentation differs dramatically from coagulopathies and systemic bleeding observed with the Central and South American bothropic envenomings. The exact mechanism of this thrombogenic phenomenon, leading to a unique envenoming syndrome, remains unknown.