bluuebunny/crossref_metadata_2025 huggingface dataset:
Short report: Field evaluation of posttreatment sensitivity for monitoring parasite clearance of Plasmodium falciparum malaria by use of the Determine Malaria pf test in central India.
Authors: Singh Neeru , Shukla M M
Published: May 2017

The posttreatment performance of the Plasmodium falciparum histidine-rich protein rapid diagnostic test Determine Malaria pf (Abbott Laboratories, Tokyo, Japan) was assessed in 70 patients in central India with uncomplicated falciparum malaria who were treated with chloroquine, sulfadoxine-pyrimethamine, and arteether. Data were compared with those of microscopy. Results revealed that the sensitivity for predicting recrudescence by means of the Determine test after treatment with chloroquine on Day 14 was 75%, with 50% specificity. However, antigenemia was detected in 16% of patients as late as Day 21 in sulfadoxine-pyrimethamine-treated subjects with a drug-sensitive response. Clearance of parasitemia in thick blood smear and clearance of antigenemia appeared to parallel each other only in arteether-treated subjects. The observed diagnostic trends therefore mean that the potential of the Determine test to detect recrudescent infection is limited.
Hepatitis C among child transfusion and adult renal dialysis patients in Indonesia.
Authors: Chanpong G Fraser , Laras Kanti , Sulaiman H Ali , Soeprapto Widodo , Purnamawati S , Sukri Nono , Sie Annie , Tan Ratna , Campbell James R , Corwin Andrew L
Published: May 2017

Hepatitis C virus (HCV) prevalence among high-risk pediatric and adult patients was evaluated. The study included 269 adults and 150 children in a case-control research design. Risk factors of HCV exposure in Indonesia were assessed among adult renal dialysis patients and pediatric patients who received multiple blood transfusions. A high prevalence of anti-HCV was found among the adult renal dialysis patients, measured by second-generation electroimmunoassay tests. Family members of dialysis patients, who served as a comparison group for dialysis patients, were found to have a 9.0% seroprevalence. The prevalence of anti-HCV among pediatric patients with hematological disorders was found to be 39.0%. The comparison group seroprevalence (pediatric patients and family members) was 4.3% among sera available for confirmatory testing. Patients with history of hospitalization (odds ratio [OR] = 7.94, 95% confidence interval [CI]: 4.06-15.51, P = 0.0001), blood transfusion (OR = 6.85, 95% CI: 3.95-11.88, P = 0.0001), circumcision (OR = 2.39, 95% CI: 1.43-3.99, P = 0.0001), or marital partner/family member history of jaundice (OR = 3.62, 95% CI: 1.97-6.62, P = 0.0001) were found to have an increased odds of HCV exposure compared with individuals without similar histories.
Practical and ethical issues in the development of a vaccine against schistosomiasis mansoni.
Authors: Todd Charles W , Colley Daniel G
Published: May 2017

Clinical trials to evaluate schistosomal vaccines are in progress. We discuss the desired characteristics of such a vaccine, propose a product profile, and consider the clinical and pre-clinical studies needed for its licensure, within practical and ethical constraints. We believe that licensure of a schistosomal vaccine will be greatly facilitated by resolution of the following issues: identification of the human immunoprotective antigens and mechanisms; induction of the appropriate responses by adjuvanted vaccines; understanding the effect of immunization on immunopathology; development of an improved serologic assay to determine worm burden; generation of approximately $500 million to fund the project; and development of a physical infrastructure with trained professionals in disease-endemic countries to perform Phase III clinical trials. We also believe that development of a schistosomal vaccine, while a long range goal, is possible and desirable, and we have indicated some of the practical steps that will be required to achieve this laudable accomplishment.
A baseline study of importance of bovines for human Schistosoma japonicum infections around Poyang Lake, China: villages studied and snail sampling strategy.
Authors: Davis George M , Wu Wei-Ping , Chen Hong-Gen , Liu Hong-Yun , Guo Jia-Gang , Lin Dan-Dan , Lu Sang-Biao , Williams Gail , Sleigh Adrian , Feng Z , McManus Donald P
Published: May 2017

An epidemiologic survey among four administrative villages around Poyang Lake, in Jiangxi Province, China (two experimental and two controls) is being conducted to determine if bovine infections are responsible for the persistence of human schistosomiasis transmission on Yangtze River marshlands. A previously published paper presented the experimental design and baseline data for humans and bovines. This paper presents basic data for the four villages using remote sensing, and baseline data for snails that includes geographic information systems and remote sensing technology to classify the areas of bovine grazing ranges and habitats suitable for snails. A new method for sampling Oncomelania snails in China is used to determine the distribution, density, and infection rates of snails throughout the grazing ranges from season to season over a four-year period. Hypothetically, treating bovines should reduce infection rates in snails to below the critical number necessary to maintain infections in man and bovines.
Comparison of hepatitis B virus and hepatitis C virus prevalence and risk factors in a community-based study.
Authors: Wang Chong-Shan , Chang Ting-Tsung , Yao Wei-Jen , Chou Pesus
Published: May 2017

We performed a community-based study of 12 villages of southern Taiwan's A-Lein Township to investigate the epidemiology of hepatitis B and hepatitis C virus (HCV) infections. Of 6,095 patients, 13.8% were positive for hepatitis B surface antigen positive (HBsAg(+)) and 17.0% were positive for anti-HCV (anti-HCV(+)). Infection was found to be inversely related to educational level and to be directly related to the frequency of the receipt of parenteral injection for medical purposes. Risk factors for HBsAg positivity were male sex, age < or = 50 years, and a family history of hepatocellular carcinoma. Risk factors for HCV seropositivity were lower education level, frequent parenteral injections, blood transfusion, menial occupations, smoking, and age > 50 years. Therefore, risk factors for HBsAg(+) and anti-HCV(+) were different in these Taiwanese communities. Safe medical injections and improved health education for high-risk groups are imperative for preventing HCV transmission.
Cryptosporidiosis in people sharing habitats with free-ranging mountain gorillas (Gorilla gorilla beringei), Uganda.
Authors: Nizeyi John Bosco , Sebunya Dennis , Dasilva Alexandre J , Cranfield Michael R , Pieniazek Norman J , Graczyk Thaddeus K
Published: May 2017

Cryptosporidiosis, a zoonotic diarrheal disease, significantly contributes to the mortality of people with impaired immune systems worldwide. Infections with an animal-adapted genotype (Genotype 2) of Cryptosporidium parvum were found in a human population in Uganda that shares habitats with free-ranging gorillas, from which the same genotype of C. parvum had been recovered previously. A high prevalence of disease was found in park staff members (21%) who frequently contact gorillas versus 3% disease prevalence in the local community. This indicates a zoonotic transmission cycle of this pathogen against which no effective prophylaxis or therapy exists. The results of the study questionnaire demonstrated a high percentage of people not undertaking appropriate precautions to prevent fecal-oral transmission of C. parvum in the Bwindi Impenetrable National Park, Uganda. This human population will benefit from stronger compliance with park regulations regarding disposal of their fecal waste within the park boundaries.
Passive surveillance as an instrument to identify risk factors for fatal Rocky Mountain spotted fever: is there more to learn?
Authors: Childs James E , Paddock Christopher D
Published: May 2017

National surveillance for Rocky Mountain spotted fever (RMSF) dates from 1920; however, the collection of detailed epidemiologic, clinical, and laboratory data on RMSF by using case report forms began in 1970. Despite issues with compliance and changes in case definitions, surveillance data have permitted researchers to assess risk factors for fatal RMSF quantitatively. Factors consistently associated with increased risk of death include severity of disease, older age, lack of tick bite, absence of classic symptoms, delay in diagnosis and initiation of appropriate antibiotic treatment, and treatment with chloramphenicol only. In several studies, treatment with a tetracycline has been shown to be protective. The continuation of current passive surveillance activities may allow researchers to refine their estimates of risk but is unlikely to produce novel results. Modified surveillance activities could focus on evaluating the risk for fatal RMSF among special populations, monitoring appropriate antibiotic use, and assessing new diagnostic tests.
Association of the IgG response to Plasmodium falciparum merozoite protein (C-terminal 19 kD) with clinical immunity to malaria in the Brazilian Amazon region.
Authors: Braga Erika Martins , Barros Rosa Maria , Reis TÃ¢nia Afonso , Fontes Cor Jesus F , Morais Cristiane GuimarÃ£es , Martins Maria SÄµnia , Krettli Antoniana Ursine
Published: May 2017

The antibody response to the C-terminal 19-kD fragment of Plasmodium falciparum merozoite surface protein-1 (PfMSP1-19) was investigated in groups of subjects living in areas of Brazil with different levels of malaria transmission. The prevalence and the levels of IgG to PfMSP1-19 increased with the time of exposure and were positively correlated with the absence of clinical symptoms in parasitemic patients. The frequency of positive response and the mean level of IgG were higher in areas where malaria prevalence was more intense, especially among asymptomatic patients. The serum absorbance values of the IgG1 isotype were significantly higher among subjects with long-term exposure and in asymptomatic infections. These data suggest a protective role of IgG1 in naturally acquired immunity in spite of the unstable transmission levels in the Brazilian Amazon.
In vitro chloroquine susceptibility and PCR analysis of pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum isolates from Senegal.
Authors: Thomas Susan M , Ndir Omar , Dieng Therese , Mboup Souleymane , Wypij David , Maguire James H , Wirth Dyann F
Published: May 2017

Chloroquine resistance has been linked to mutations in the pfcrt and pfmdr1 genes of Plasmodium falciparum. To estimate the prevalence of the pfcrt K76T, pfmdr1 N86Y, and pfmdr1 D1246Y polymorphisms, isolates of P. falciparum from Senegal, West Africa, were analyzed, and the results were compared to in vitro chloroquine susceptibility. By the in vitro DELI test, 31% of these samples were resistant to chloroquine. Polymerase chain reaction-based assays and confirmatory sequencing demonstrated the pfcrt T76, pfmdr1 Y86, and pfmdr1 Y1246 alleles in 79%, 31%, and 2% of the isolates, respectively. All three mutant alleles were present in both in vitro susceptible and resistant isolates. On the basis of these findings, it appears that these molecular markers are not consistently predictive of in vitro chloroquine resistance in Senegal.
Polyclonal Plasmodium falciparum malaria in travelers and selection of antifolate mutations after proguanil prophylaxis.
Authors: FÃ¤rnert Anna , Tengstam Karolin , Palme Ingela Berggren , Bronner Ulf , Lebbad Marianne , Swedberg GÃ¶te , BjÃ¶rkman Anders
Published: May 2017

The polymorphism of malaria parasites will greatly influence the efficiency of antimalarial drugs and vaccines. This study determined the genetic diversity of Plasmodium falciparum infections in 107 travelers and estimated the importance of mutations in the parasite dihydrofolate reductase (dhfr) gene for clinical breakthrough during proguanil prophylaxis. Genotyping with regards to the three highly polymorphic antigen-coding regions (merozoite surface protein-1 [msp-1], msp-2, and the glutamate-rich protein [glurp]) revealed multiple genotypes (up to five) in 64% of the patients. Single genotype infections were mainly associated with prior intake of antimalarial drugs, but also with a shorter stay in a malaria-endemic area and low parasite density. Malaria breakthrough despite proguanil prophylaxis was always associated with mutations in the dhfr gene; always the Asn-108 mutation and often the Ile-51 and Arg-59 mutations. The Leu-164 mutation was found in four travelers from Africa. Travelers with limited time in an endemic area were often infected with polyclonal P. falciparum infections, which suggests that single mosquito inoculations are often composed of several genetically diverse parasites. Chemoprophylaxis reduces the number of infecting clones and selects for resistant parasites as shown for proguanil through mutations in the dhfr gene.
One year's experience with the polymerase chain reaction as a routine method for the diagnosis of imported malaria.
Authors: Morassin B , Fabre R , Berry A , Magnaval J F
Published: May 2017

Given the problems encountered in westernized countries with the laboratory diagnosis of malaria, namely sensitivity of the conventional methods and detection of mixed infections, a polymerase chain reaction (PCR)-based diagnosis has been developed and routinely used. The PCR used two sets of primers to simultaneously detect any infection due to the genus Plasmodium, or to the species P. falciparum. The PCR results were available within six hours. Five hundred twenty-nine patients were tested, of whom 136 were found positive by the PCR, and only 104 by the quantitative buffy coat (QBC) method. The 32 discrepancies were analyzed on the basis of the clinical data, and technical, molecular, and sequencing findings to ascertain the presence of Plasmodium DNA. The PCR-based diagnosis of malaria appeared to be a useful tool that was suitable as a second-line method when the results of conventional techniques were negative in patients presenting a syndromeconsistent with malaria, as well as yielding an accurate species identification.
Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.
Authors: Nde Pius N , Pogonka Thomas , Bradley Janette E , Titanji Vincent P K , Lucius Richard
Published: May 2017

Onchocerciasis remains a major health hazard in many tropical countries. However, the existing tools for diagnosis of the disease have limitations, particularly regarding the detection of low level or early infections. To design an optimized reagent, we exploited the high antibody reactivity of patient sera against the Onchocerca volvulus proteins Ov20 and Ov33, which have been described as highly sensitive and specific immunodiagnostic reagents for producing hybrid proteins. The construct OvH2 was composed of Ov20 fused to Ov33, while OvH3 consisted of the C-terminus of Ov20 linked to Ov33. When these constructs were tested with sera from patients with onchocerciasis and control sera, OvH2 showed a sensitivity of 98.5% and a specificity of 97.7% and OvH3 showed a sensitivity of 98.5% and a specificity of 95.35%. All non-responders were from Ecuador. These results surpass those of existing single recombinant antigens, suggesting that our hybrid proteins combined the sensitivity of the two parent proteins. Tests based on OvH2 should prove suitable for monitoring onchocerciasis control programs and individual diagnosis.
Identification of mosquito avian-derived blood meals by polymerase chain reaction-heteroduplex analysis.
Authors: Lee Joon Hak , Hassan Hassan , Hill Geoff , Cupp Eddie W , Higazi Tarig B , Mitchell Carl J , Godsey Marvin S , Unnasch Thomas R
Published: May 2017

A polymerase chain reaction (PCR) heteroduplex assay (HDA) was developed to identify avian derived mosquito blood meals to the species level. The assay used primers amplifying a fragment of the cytochrome B gene from vertebrate but not invertebrate species. In Culex tarsalis fed on quail, PCR products derived from the quail cytochrome B gene were detected seven days post-engorgement. In an analysis of wild-caught mosquitoes, 85% of blood-fed mosquitoes produced detectable PCR products. Heteroduplex patterns obtained from bird-derived PCR products were found to permit the unambiguous identification of all species examined. No intraspecific variation in HDA patterns was found. The PCR-HDA was used to characterize blood meals in wild caught Cx. tarsalis. Of the 67 blood meals analyzed, 60% were derived from avian sources. Of the avian blood meals, 65% were derived from a single host, the common grackle.
Chemotactic migration of the Lyme disease spirochete (Borrelia burgdorferi) to salivary gland extracts of vector ticks.
Authors: Shih Chien-Ming , Chao Li-Lian , Yu Chia-Pan
Published: May 2017

The migration of Lyme disease spirochetes (Borrelia burgdorferi) toward salivary gland extracts (SGEs) of vector ticks was determined by a modified U-tube chemotaxis assay. Responses of cultured spirochetes to the SGEs were measured by dark-field microscopy at intervals after the initial inoculation. The average numbers of spirochetes that migrated were compared between U-tubes containing either SGEs or phosphate-buffered saline (PBS). Spirochetes showed increased migration in tubes containing SGE, and migration was approximately 10-20-fold higher than that for spirochetes observed in tubes containing PBS. In addition, the span of migration showed no significant difference relative to the origin of spirochete isolation. These results demonstrate that spirochete migration can be enhanced by SGEs from fed vector ticks. This mechanism may contribute to the novel transmission of Lyme disease spirochetes between cofeeding infected and uninfected ticks in nature.
High prevalence of asymptomatic Plasmodium vivax and Plasmodium falciparum infections in native Amazonian populations.
Authors: Alves Fabiana P , Durlacher Rui R , Menezes Maria J , Krieger Henrique , Silva Luiz H Pereira , Camargo Erney P
Published: May 2017

The epidemiology of malaria in 2 riverine localities in RondÄµnia, Brazilian western AmazÄµnia, was assessed by a 1-year study at Portuchuelo, and a cross-sectional survey at riverine communities at Rio Machado (= Ji-Parana). Plasmodium spp. infections were diagnosed by light microscopy and by polymerase chain reaction (PCR) amplification of ribosomal DNA. PCR was 6-7 times more efficient than microscopy for detecting plasmodial infections. Both Plasmodium vivax and Plasmodium falciparum infections occurred as asymptomatic and symptomatic forms of the disease. The relation between symptomatic and asymptomatic clinical forms was roughly similar for both species of Plasmodium. Symptomless patients were monitored for 2 months. The prevalence of symptomless infections was 4-5 times higher than the symptomatic ones--respectively, 20% and 4.6% for Portuchuelo and 49.5% and 10% for Ji-Parana. Symptomatic malaria occurred mostly in patients in younger age groups. In contrast, there was a significant association of symptomless malaria with older age groups (medians of 26.5 and 21 years, respectively, for Portuchuelo and Ji-Parana), whereas the age medians for symptomatic malaria were 14 and 8 years, respectively, in the 2 regions. Symptomatic malaria also was more prevalent in groups living for shorter times in AmazÄµnia (13 and 4 years, respectively, for Portuchuelo and Ji-ParanA) as compared with symptomless malaria, which was more prevalent in groups living for longer periods in the region (medians of 25.5 and 18 years, respectively, for Portuchuelo and Ji-ParanÃ¡). The high prevalence of symptomless malaria may pose new problems for the currently adopted strategy for the control of malaria in the Amazonian region, which is essentially based on the treatment of symptomatic patients.
In vitro reversal of chloroquine resistance in Plasmodium falciparum with dihydroethanoanthracene derivatives.
Authors: Pradines Bruno , Alibert-Franco Sandrine , Houdoin Carole , Mosnier Joel , Santelli-Rouvier Christiane , Papa Vincent , Rogier Christophe , Fusai Thierry , Barbe Jacques , Parzy Daniel
Published: May 2017

The effects of combining four dihydroethanoanthracenic (DEA) derivatives and chloroquine were assessed in vitro against Plasmodium falciparum chloroquine resistant parasites W2, Palo Alto, FCR3, and Bres1. Like verapamil or promethazine, the four dihydroethanoanthracenic derivatives tested can be added to the growing list of agents that show capability in enhancing the activity of chloroquine against resistant parasites. The structurally related tricyclic antihistaminic compounds examined in this study exerted different intrinsic antimalarial activity, but the same chloroquine-potentiating activity as verapamil or promethazine. They may act both on the rate of chloroquine accumulation and on its access to ferriprotoporphyrin IX. The reversal mechanism would be assumed to result from competition between DEA derivatives and chloroquine for efflux translocation sites, thus causing an increase in steady-state accumulation of chloroquine and a return to susceptibility. Restoration of therapeutic efficacy of chloroquine against resistant parasites by the administration of an additional drug available at relatively low cost may be a more effective strategy than the introduction of another antimalarial drug at the national level.
Nonimmune IgM, but not IgG binds to the surface of Plasmodium falciparum-infected erythrocytes and correlates with rosetting and severe malaria.
Authors: Rowe J Alexandra , Shafi Juma , Kai Oscar K , Marsh Kevin , Raza Ahmed
Published: May 2017

Recent work suggests that IgG and IgM from nonimmune human serum (natural antibodies) bind to the surface of Plasmodium falciparum-infected erythrocytes and contribute to rosette formation by stabilizing the interaction between infected and uninfected erythrocytes. Here we show, in both laboratory clones and field isolates, that only IgM but not IgG is detected on the surface of infected cells. In field isolates, there was a strong positive correlation between IgM binding and rosette formation (Spearman's rank correlation coefficient p = 0.804, P < 0.001). Both rosette formation and IgM binding were associated with severe malaria, although statistical analysis indicates that rosette formation is the more strongly associated variable. Rosette formation, but not IgM binding, was also associated with malarial anemia. We conclude that IgM is the predominant class of natural antibodies binding to the surface of infected erythrocytes. However, we could not confirm previous suggestions that infected erythrocytes are coated with nonimmune IgG, which could lead to their interaction with host Fcgamma receptors.
Andes virus associated with hantavirus pulmonary syndrome in northern Argentina and determination of the precise site of infection.
Authors: Gonzalez Della Valle M , Edelstein A , Miguel S , Martinez V , Cortez J , Cacace M L , Jurgelenas G , Sosa Estani S , Padula P
Published: May 2017

Hantavirus pulmonary syndrome (HPS) has been documented in the Salta and Jujuy provinces of northern Argentina since 1991 and 1997, respectively, accounting for almost 50% of the cases of HPS reported in this country. Andes (AND) virus, specifically the AND virus Nort lineage, was previously associated with human disease in this region. Genetic analysis of viral medium RNA segments obtained from 18 HPS cases showed the existence of three AND virus Nort sublineages co-circulating in these two provinces. They showed a nucleotide sequence diversity of up to 11.1% between the sublineages. The putative site of infection of one of these cases (Sal3/97) was determined. A 100% nucleotide sequence identity was observed between the viral sequence found in patient Sal3/97 and in two virus-positive Oligoryzomys chacoensis captured in the same place where the case lived and worked. These results indicated the putative site of infection and identified this rodent species as the source of infection.
Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.
Authors: SÃ¡nchez-GuillÃ©n MarÃ­a Del Carmen , PÃ©rez-Fuentes Ricardo , Salgado-Rosas Hilda , Ruiz-ArgÃ¼elles Alejandro , Ackers John , Shire Abdirashid , Talamas-Rohana Patricia
Published: May 2017

To correlate a particular state of immunity with Entamoeba spp., we used colorimetric PCR to differentiate E. histolytica from E. dispar in individuals with amoebiasis and to associate its presence with the clinical profile, including humoral and cellular immune responses to E. histolytica. Our results showed high levels of antibody in acute amoebiasis and elevation of IL-4 production, a cytokine related to Th2 profile, associated with E. histolytica. In chronic amoebiasis, even with anti-E. histolytica seropositivity, intestinal symptoms were associated with E. dispar in all the cases, without differences in level of antibodies, BTI, CD4+/CD8+ ratio, INF-gamma, and IL-4. Among asymptomatic carriers, E. dispar was more frequently found; however, identification of E. histolytica in two asymptomatic carriers associated with high levels of INF-gamma, a cytokine related to Th1 profile, demonstrate the importance of making specific diagnosis of Entamoeba spp., to establish the clinical and epidemiological behavior in both intestinal and extra-intestinal amoebiasis.
Heterogeneity, geographic distribution, and pathogenicity of serodemes of Leishmania viannia in Colombia.
Authors: Saravia Nancy Gore , Weigle Kristen , Navas Claudia , Segura Iris , Valderrama Liliana , Valencia Anais Zully , Escorcia Blanca , McMahon-Pratt Diane
Published: May 2017

Leishmania Viannia strains from 1,092 patients who acquired dermal leishmaniasis in endemic regions of Colombia were analyzed for expression of species and subgenus specific epitopes. Eight monoclonal antibodies prepared against membranes of the major species of the Viannia subgenus and previously shown to distinguish these species, recognized low molecular mass (< 45kD) membrane components. Thirteen widely but non-uniformly distributed serodemes were identified: one unique to L. panamensis, four unique to L. braziliensis and eight that were common to L. braziliensis and L. guyanensis. Thirty-seven percent of Colombian L. braziliensis strains concomitantly typed by isoenzymes were null, i.e., not recognized by the corresponding species-specific B-16 or B-18 antibodies. No Colombian L. guyanensis strains were recognized by the antibody specific for this species (B-19). In contrast, L. panamensis-specific B-4 and B11 antibodies recognized > 98% of the L. panamensis strains. Null strains of L. braziliensis and L. panamensis were more frequently isolated from mucosal leishmaniasis than strains that expressed species specific epitopes, suggesting that these strains may be more pathogenic.
Hypereosinophilia and liver mass in an immigrant.
Authors: Noyer Charles M , Coyle Christina M , Werner Craig , Dupouy-Camet Jean , Tanowitz Herbert B , Wiitner Murray
Published: May 2017

Human infection with the sheep liver fluke Fasciola hepatica is a global zoonosis that usually parallels the prevalence of infection in sheep and other ruminants. The disease is endemic in South and Central America, Puerto Rico, the Caribbean region, many parts of Africa, Asia, the Middle East, Australia, and China. There have been a number of focal outbreaks reported from Europe, including southern France and the Mediterranean region. Since acute fascioliasis has rarely been reported in the United States, physicians in this country frequently overlook the diagnosis. Therefore, we report a case of acute human fascioliasis and review the pathogenesis, diagnosis, and treatment of this disease in a recently arrived immigrant.
Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in GoiÃ¢nia, GoiÃ¡s, Brazil.
Authors: Pereira Maria Das GraÃ§as Cabral , Atwill Edward Robert , Barbosa Alverne Passos , Silva Simonne Almeida E , GarcÃ­a-Zapata Marco Tulio Antonio
Published: May 2017

A cross-sectional study was conducted for assessing the prevalence of and risk factors associated with Cryptosporidium parvum in diarrheic children who were hospitalized in GoiÃ¢nia, capital of GoiÃ¡s State in Brazil. A crude prevalence of 14.4% (64 of 445) was observed using a direct immunfluorescent assay (DFA), but the true prevalence was 18.7% (83 of 445) when a gold standard of immunomagnetic separation was used in combination with the DFA. Infection was more predominant in children less than 24 months old (odds ratio [OR] = 0.50, 90% confidence interval [CI] = 0.36-0.68, P = 0.0001), and males were 2.2 times more at risk for infection when compared with females (OR = 2.2. 90% CI = 0.13-3.8, P = 0.01). The socioeconomic, intra-familial, and environmental factors associated with cryptosporidiosis were day care attendance, household children with diarrhea up to 30 days prior to the interview, contact with surface water within past 30 days prior to the interview, dwelling distance from a body of water, and the late rainy season (P < 0.10). C. parvum was not associated with the parent's occupation, household sleeping arrangements, number of caregivers, breast-fed children, diet and type of food hygiene, source and type of treatment of drinking water, presence of sewage, and animal exposure (P > 0.10). Although weight was not found to be associated with infection, children infected with C parvum weighed on average 2.0% less than children not infected with C. parvum (P > 0.10). Thus, C. parvum is an important etiologic agent of childhood diarrhea and should be identified in routine parasitologic tests of diarrheal stool samples.
Seasonal prevalence of intestinal parasites in the United States during 2000.
Authors: Amin Omar M
Published: May 2017

One-third of 5,792 fecal specimens from 2,896 patients in 48 states and the District of Columbia tested positive for intestinal parasites during the year 2000. Multiple infections with 2-4 parasitic species constituted 10% of 916 infected cases. Blastocystis hominis infected 662 patients (23% or 72% of the 916 cases). Its prevalence appears to be increasing in recent years. Eighteen other species of intestinal parasites were identified. Cryptosporidium parvum and Entamoeba histolytica/E. dispar ranked second and third in prevalence, respectively. Prevalence of infection was lowest (22-27%) in winter, gradually increased during the spring, reached peaks of 36-43% between July and October, and gradually decreased to 32% in December. A new superior method of parasite detection using the Proto-fix-CONSED system for fixing, transport, and processing of fecal specimens is described. In single infections, pathogenic protozoa caused asymptomatic subclinical infections in 0-31 % of the cases and non-pathogenic protozoa unexpectedly caused symptoms in 73-100% of the cases. The relationship between Charcot-Leyden crystals and infection with four species of intestinal parasites is examined and the list of provoking parasitic causes is expanded.
A cocktail polymerase chain reaction assay to identify members of the Anopheles funestus (Diptera: Culicidae) group.
Authors: Koekemoer L L , Kamau L , Hunt R H , Coetzee M
Published: May 2017

Anopheles funestus Giles is a major malaria vector in Africa belonging to a group of species with morphologically similar characteristics. Morphological identification of members of the A. funestus group is difficult because of overlap of distinguishing characteristics in adult or immature stages as well as the necessity to rear isofemale lines to examine larval and egg characters. A rapid rDNA polymerase chain reaction (PCR) method has been developed to accurately identify five members of the A. funestus group. This PCR is based on species-specific primers in the ITS2 region on the rDNA to identify A. funestus (approximately 505bp), Anopheles vaneedeni Gillies and Coetzee (approximately 587bp), Anopheles rivulorum Leeson (approximately 411bp), Anopheles leesoni Evans (approximately 146bp), and Anopheles parensis Gillies (approximately 252bp).
Evaluation of antigens from various Leishmania species in a Western blot for diagnosis of American tegumentary leishmaniasis.
Authors: GonÃ§alves Cely Cristina Martins , Reiche Edna Maria Vissoci , De Abreu Filho BenÃ­cio Alves , Silveira Thais Gomes Verzignassi , Felizardo TÃ¢nia Cristina , Maia Karoline Rocha , Costacurta Rafael , Padovesi Evandro JosÃ© , Dias Filho Benedito Prado , Jankevicius Shiduca Itow , Jankevicius JosÃ© Vitor
Published: May 2017

A Western blot method that uses antigens from culture promastigote forms of Leishmania (Viannia) braziliensis, L. (Leishmania) amazonensis, L. (Leishmania) tropica, and a trypanosomatid (strain 268T) isolated from naturally infected tomatoes was evaluated for laboratory diagnosis of American tegumentary leishmaniasis (ATL). Serum samples were obtained from 108 patients with ATL (group I), 23 chagasic patients (group II), 32 patients with other diseases (group III), and 78 healthy individuals (group IV). The overall analysis showed a sensitivity of 76.90%, 90.40%, 78.50%, and 87.90%, a specificity of 100%, 93.80%, 87.80%, and 77.10%, a positive predictive value of 100%, 94.00%, 89.50%, and 72.50%, a negative predictive value of 75.70%, 90.00%, 75.40%, and 90.20%, and a concordance coefficient kappa of 0.7358, 0.8400, 0.6491, and 0.6287 for L. (V.) braziliensis, L. (L.) amazonensis, L. (L.) tropica, and strain 268T antigens, respectively. The antigenic profile recognized by serum samples from patients with ATL and with Chagas' disease permits serologic distinction between these infections.
Validity of nodule palpation in a Simulium neavei-transmitted onchocerciasis area in Uganda.
Authors: Kipp Walter , Bamhuhiiga Jotham
Published: May 2017

The objective of this study was to evaluate the prevalence of palpable nodules as a rapid indicator for onchocerciasis endemicity in at-risk communities where Simulium neavei s.s. is the transmitting vector. We used data collected from 13 villages in Uganda to determine the validity of this rapid assessment method. The prevalence of palpable nodules was closely associated with the microfilarial prevalence (R2 = 0.603, P = 0.002), with the community filarial load (R2 = 0.620, P = 0.001) and with the prevalence of onchodermatitis. Nodule palpation in males more than 20 years old, using a cut-off point of 40% and higher for the nodule prevalence, had a sensitivity of 92% and a specificity of 100% in correctly identifying communities in need of urgent intervention with ivermectin mass treatment. Cut-off points were based on World Health Organization recommendations. Thus, nodule palpation can replace skin snipping to identify communities at serious risk of S. neavei-transmitted onchocerciasis.
Comparison of field and expert laboratory microscopy for active surveillance for asymptomatic Plasmodium falciparum and Plasmodium vivax in western Thailand.
Authors: Coleman Russell E , Maneechai Nongnuj , Rachaphaew Nattawan , Kumpitak Chalermpol , Miller R Scott , Soyseng Virat , Thimasarn Krongthong , Sattabongkot Jetsumon
Published: May 2017

Microscopy of Giemsa-stained thick and thin films by a skilled microscopist has remained the standard laboratory method for the diagnosis of malaria. However, diagnosis of malaria with this method is problematic since interpretation of results requires considerable expertise, particularly at low parasite levels. We compared the efficacy of "field" and "expert laboratory" microscopy for active surveillance of Plasmodium falciparum and P. vivax in western Thailand. Field microscopy consisted of an approximately five-minute read (50-100 fields) of a thick film at x700 using a natural light source, whereas expert laboratory microscopy consisted of a 20-minute read (number of parasites per 500 leukocytes) at x1,000 using a high-quality, well-maintained microscope with an artificial light source. All discordant and 20% of concordant results were cross-checked blindly. A total of 3,004 blood films collected between May and November 2000 were included in the study, of which 156 (5.2%) were positive for P. falciparum, 177 (5.9%) for P. vivax, and 4 (0.1%) for both P. falciparum and P. vivax by expert microscopy. A total of 84.4% (135 of 160) of the P. falciparum-positive slides and 93.9% of the P. vivax-positive slides had a parasitemia of less than 500/microL. Field microscopy was specific (99.3%) but not sensitive (10.0%) for the diagnosis of P. falciparum malaria, with a positive predictive value (PPV) of 43.2% and a negative predictive value (NPV) of 95.1%. The corresponding specificity and sensitivity for the diagnosis of P. vivax malaria were 99.2% and 7.1%, respectively, with a PPV of 38.7% and an NPV of 93.9%. Field microscopy, as defined in this study, is not an effective method for active malaria surveillance in western Thailand, where prevalence and parasitemia rates are low.
Persistence of dengue-3 virus through transovarial transmission passage in successive generations of Aedes aegypti mosquitoes.
Authors: Joshi Vinod , Mourya D T , Sharma R C
Published: May 2017

Progeny of Aedes aegypti mosquitoes infected intrathoracically with dengue-3 virus was reared to subsequent generations. In each generation, blood-fed females were confined individually and the eggs obtained from the transovarially infected females were pooled. The seventh generation obtained from the infected parental mosquitoes showed that virus could persist in mosquitoes in successive generations through transovarial passage. The rate of vertical transmission initially increased in the few generations (F1-F2), but in subsequent generations it was found to be steady. Parental mosquitoes inoculated with virus showed higher mortality than the diluent-inoculated controls. There was an increase in the larval duration of transovarially infected batches at the seventh generation when compared with uninfected control mosquitoes. The fecundity and fertility of the transovarially infected batches of mosquitoes was also affected when compared with the controls. This is the first report demonstrating persistence of dengue virus in the successive generations of mosquitoes infected through vertical transmission. These observations, which have great epidemiologic importance, suggest that vector mosquitoes may play an important role in the maintenance of virus in nature, and that mosquitoes may act as reservoirs of these viruses.
The impact of single-dose diethylcarbamazine treatment of bancroftian filariasis in a low-endemicity setting in Egypt.
Authors: Ramzy Reda M R , el-Setouhy Maged , Helmy Hanan , Kandil Amr M , Ahmed Ehab S , Farid Hoda A , Faris Rifky , Weil Gary J
Published: May 2017

This study was designed to evaluate the effect of a single dose of diethylcarbamazine (DEC, 6 mg/kg) on Wuchereria bancrofti infections in a low-endemicity setting in Egypt (microfilaremia, or MF, 3.7%, median MF 34/mL). Subjects with MF or filarial antigenemia were treated and restudied 1 year later. Treatment with DEC dramatically reduced blood MF counts, with clearance in 69% of subjects. Treatment also reduced filarial antigen levels, but low clearance rates suggest that some adult worms survived treatment in most patients. Mass treatment was administered in one village; 27 months later, MF prevalence had decreased 84% (from 4.9% to 0.8%). These results show that single-dose DEC treatment can have a major effect on MF prevalence rates and levels in low-endemicity settings. Although the World Health Organization advocates repeated multidrug regimens for filariasis elimination, mass treatment with DEC alone may be sufficient to interrupt transmission in areas with low infection intensities and prevalence rates.
Helicobacter pylori infection in Kazakhstan: effect of water source and household hygiene.
Authors: Nurgalieva Zhannat Z , Malaty Hoda M , Graham David Y , Almuchambetova R , Machmudova A , Kapsultanova D , Osato Michael S , Hollinger F Blaine , Zhangabylov Abai
Published: May 2017

The epidemiology of Helicobacter pylori infection and risk factors associated with its transmission are not well understood. Kazakhstan is country with two ethnic groups, Asian (Kazakhs) and Western (Russians), living under similar socioeconomic conditions. The aim of this study was to examine the seroepidemiologic pattern of H. pylori and hepatitis A among the same individuals from both ethnic groups, with emphasis on water source and household sanitation practices. This was a cross-sectional seroepidemiologic study conducted among unrelated healthy individuals in Kazakhstan. From May through August 1999, individuals between the ages of 10 and 60 years from Almaty, Kazakhstan, were invited to participate. Demographic information, socioeconomic factors, living conditions, and various aspects of the local household environment including access to water were collected. A clean water index (CWI) was created based on combined factors, consistency of boiling water before drinking, frequency of storing and reusing water, and frequency of bathing and showering. H. pylori and hepatitis A antibodies were assessed by enzyme-linked immunosorbent assay. Two hundred eighty-eight individuals between the ages of 10 and 60 years participated. The prevalence of H. pylori infection was almost identical among the two ethnic groups (Russians 79% and Kazakhs 80%). H. pylori infection was inversely correlated with the CWI (i.e., 56%, 79%, and 95% for high, middle, and low, respectively (P < .05). Drinking river water had highest risk of H. pylori infection (OR = 13.6, 95% CI = 1.8-102.4; P < .01, compared with tap water). Crowding showed no significant effect on H. pylori prevalence. Anti-HAV antibodies were found in 86% of the population, 90% among the Russians versus 82% among the Kazakhs (OR = 1.8, 95% CI = 1.1-3.8, P = .05). Although the two infections were highly correlated (P < .001), antibody to both infections were present simultaneously in only 74%. The prevalence of H. pylori infection in Kazakhstan is very high. The data suggest that transmission of H. pylori can be water borne, related to poor sanitary practices, or both. The high prevalence of antibodies to H. pylori and HAV among this population is a marker for poor sanitation and hygienic practices. Reducing the rate of H. pylori transmission will require improvements in overall sanitation including clean water, waste disposal, as well as in household hygienic practices.
Beliefs and attitudes toward Buruli ulcer in Ghana.
Authors: Stienstra Ymkje , van der Graaf Winette T A , Asamoa Kwame , van der Werf Tjip S
Published: May 2017

Buruli ulcer is a devastating emerging disease in tropical countries. Quantitative and qualitative data were obtained by interviewing patients with this disease and control subjects in Ghana. Common perceived causes were witchcraft and curses. Other reported causes were personal hygiene, environment, and close contact with a patient with this disease. Financial difficulties, fear of the mutilating aspects of treatment, and social stigma were the main reasons found for delay in obtaining treatment. Patients are reluctant to seek treatment outside their own community. Patients often expected medical treatment instead of surgery, and underestimated the duration of hospital admission. The stigma of the disease is huge, and is strongly associated with the mysterious nature of the condition, the lack of knowledge about its mode of transmission, and the lack of proper treatment. Stigma scores were higher in unaffected respondents and in a less endemic location. Education on the disease, usually propagated for early case detection, might be useful in reducing stigma.
Short report: molecular genetic characterization of an unusually severe case of hydatid disease in Alaska caused by the cervid strain of Echinococcus granulosus.
Authors: McManus Donald P , Zhang Lihua , Castrodale Louisa J , Le Thanh Hoa , Pearson Mark , Blair David
Published: May 2017

Distinct Echinococcus granulosus life cycle patterns have been described in North America: domestic and sylvatic. Gene sequences of the sylvatic E. granulosus indicate that it represents a separate variant. Case-based data have suggested that the course of sylvatic disease is less severe than that of domestic disease, which led to the recommendation to treat cystic echinococcosis patients in the Arctic by careful medical management rather than by aggressive surgery. We recently reported the first two documented E. granulosus human cases in Alaska, with accompanying severe sequelae. Here we describe the results of molecular genetic analysis of the cyst material of one of the subjects that supported identification of the parasite as the sylvatic (cervid) strain and not the domestic (common sheep strain), which was initially thought to be implicated in these unusually severe Alaskan cases.
Infection dynamics of Sin Nombre virus after a widespread decline in host populations.
Authors: Boone John D , McGwire Kenneth C , Otteson Elmer W , DeBaca Robert S , Kuhn Edward A , St Jeor Stephen C
Published: May 2017

Many researchers have speculated that infection dynamics of Sin Nombre virus are driven by density patterns of its major host, Peromyscus maniculatus. Few, if any, studies have examined this question systematically at a realistically large spatial scale, however. We collected data from 159 independent field sites within a 1 million-hectare study area in Nevada and California, from 1995-1998. In 1997, there was a widespread and substantial reduction in host density. This reduction in host density did not reduce seroprevalence of antibody to Sin Nombre virus within host populations. During this period, however, there was a significant reduction in the likelihood that antibody-positive mice had detectable virus in their blood, as determined by reverse-transcriptase polymerase chain reaction. Our findings suggest 2 possible causal mechanisms for this reduction: an apparent change in the age structure of host populations and landscape-scale patterns of host density. This study indicates that a relationship does exist between host density and infection dynamics and that this relationship concurrently operates at different spatial scales. It also highlights the limitations of antibody seroprevalence as a metric of infections, especially during transient host-density fluctuations.
Community-based dengue prevention programs in Puerto Rico: impact on knowledge, behavior, and residential mosquito infestation.
Authors: Winch Peter J , Leontsini Elli , Rigau-Pérez José G , Ruiz-Pérez Mervin , Clark Gary G , Gubler Duane J
Published: May 2017

Dengue is a major health burden in Puerto Rico. Televised public service announcements and posters, elementary and pre-school educational programs, and an exhibit at the Children's Museum in Old San Juan were evaluated separately using knowledge and practices surveys administered to children and their parents, surveys of house lots for larval container habitats, focus groups, and interviews with program organizers and participants. Exposure to the programs was associated with increased dengue-related knowledge, increased proportion of tires protected from rain, decreased proportion of water storage containers positive for mosquito larvae, and increased indoor use of aerosol insecticides. Exposure to the elementary school program was associated with slightly lower indices of residential mosquito infestation. The programs have resulted in high levels of awareness, some behavior change, and limited change in larval indices. Greater emphasis on the skills necessary for community members to keep containers free of mosquito larvae would increase program effectiveness.