bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis A in Latin America: a changing epidemiologic pattern.
Authors: Tapia-Conyer R , Santos J I , Cavalcanti A M , Urdaneta E , Rivera L , Manterola A , Potin M , Ruttiman R , Tanaka Kido J
Published: May 2017

In a multicenter study, hepatitis A virus (HAV) seroprevalence was surveyed in six countries in Latin America in which in 12,000 subjects were stratified for age. The highest rates of seroprevalence were recorded in the Dominican Republic (89.0%) and Mexico (81.0%), with lower rates in Brazil (64.7%), Chile (58.1%), Venezuela (55.7%), and Argentina (55.0%). The seroprevalence of HAV in children between 1 and 5 years of age was less than 50%, except in the Dominican Republic. In the 5-10-year-old age group, seroprevalence rates have also decreased compared with previous reports. This suggests that the epidemiology is shifting from high to intermediate endemicity, with the population susceptible to HAV infection shifting from children to adolescents and adults. Furthermore, data from Brazil, Argentina, and Mexico show that HAV seroprevalence is significantly lower in people living in medium and high socioeconomic conditions. This study suggests the need for appropriate vaccination programs to be implemented targeting children, adolescents, and adults, particularly in higher socioeconomic groups.
Mansonella ozzardi infection in Bolivia: prevalence and clinical associations in the Chaco region.
Authors: Bartoloni A , Cancrini G , Bartalesi F , Marcolin D , Roselli M , Arce C C , Hall A J
Published: May 2017

A cross-sectional survey carried out in the Chaco region of Bolivia showed that 26% (77 of 296) and 0.7% (2 of 298) of the rural population of the Camiri and Villa Montes areas, respectively, harbored Mansonella ozzardi microfilariae (mf). No significant differences were observed between sexes. The lowest prevalence (9%) was in the 0-14-year-old age group, with no children <11 months of age infected. The prevalence increased sharply in the 25-34-year-old age group (32%), and continued increasing in the older age classes. Microfilaremia, ranging from 1 to 305 mf/20 microl of blood, was lowest in 0-14-year-old children (geometric mean concentration = 1.1 mf/20 microl), and increased with age (>100 mf/20 microl in people >44 years old). An expected increasing sensitivity with the blood volume examined was observed. No significant association between clinical symptoms (fever, skin rash, pruritus, headache, lymphedema, elephantiasis, and articular pain) and microfilaremia was observed.
Human trichinellosis in Sourthern Spain: serologic and epidemiologic study.
Authors: Rodriguez-Osorio M , Abad J M , de Haro T , Villa-Real R , GÃ³mez-Garcia V
Published: May 2017

An outbreak of trichinellosis caused by wild boar meat occurred in the Iruela (Jaen) in southern Spain in February 1996. Thirty-five people were diagnosed on the basis of epidemiologic data, but only 24 patients agreed to participate in this study. Twenty-three (96%) had symptoms suggestive of trichinellosis. Immunofluorescent and Western blot test results for trichinellosis were positive in 18 persons, and 15 had circulating Trichinella spiralis antigens. These findings suggest that results of tests for circulating antigens in conjunction with clinical presentation are useful for the diagnosis of trichinellosis.
Genetic analysis of leishmania parasites in Ecuador: are Leishmania (Viannia) panamensis and Leishmania (V.) Guyanensis distinct taxa?
Authors: BaÃ±uls A L , Jonquieres R , Guerrini F , Le Pont F , Barrera C , Espinel I , Guderian R , Echeverria R , Tibayrenc M
Published: May 2017

In the course of an epidemiologic survey in Ecuador, the following collection of Leishmania stocks was isolated: 28 from patients with clinical signs of leishmaniasis, 2 from sloths, 1 from a dog, and 4 from sand flies. For genetic characterization of these stocks, multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA (RAPD) were used. Twenty six of the 35 stocks were identified as either Leishmania (V.) panamensis or L. (V.) guyanensis, 2 stocks were identified as L. (V.) braziliensis, the 2 stocks from sloths showed specific genotypes, and 5 stocks were characterized as hybrids between L. (V.) braziliensis and L. (V.) guyanensis. These data show that genetic diversity of Leishmania in Ecuador is high and that L. (V.) panamensis/guyanensis is the dominant group in this country. The genetic analysis questioned the distinctness between the two species L.(V.) panamensis and L. (V.) guyanensis, since MLEE and RAPD data did not indicate that L. (V.) panamensis and L. (V.) guyanensis correspond to distinct monophyletic lines. Population genetic analysis performed on the L. (V.) panamensis/guyanensis group favors the hypothesis of a basically clonal population structure.
Markedly high seroprevalence of hepatitis B virus infection in comparison to hepatitis C virus and human T lymphotropic virus type-1 infections in selected Solomon Islands populations.
Authors: Furusyo N , Hayashi J , Kakuda K , Sawayama Y , Ariyama I , Eddie R , Kashiwagi S
Published: May 2017

To determine the prevalences of hepatitis B virus (HBV), hepatitis C virus (HCV), and human T lymphotropic virus type-1 (HTLV-1) infections in residents of the Solomon Islands, we surveyed 1,610 serum samples from 1,113 outpatients and 497 healthy volunteer blood donors at the Central Hospital in Honiara, the Solomon Islands. The prevalence of hepatitis B surface antigen (HBsAg) by radioimmunoassay (RIA) (n = 315, 19.6%) was significantly different from that of antibody to HCV (anti-HCV) by a second-generation enzyme immunoassay (EIA) (n = 4, 0.2%) and antibody to HTLV-1 (anti-HTLV-1) by an ELISA with Western blot analysis to verify the positivity (n = 49, 3.0%) (P < 0.0001, respectively). There were no significant differences in the prevalences of these markers between outpatients and blood donors. Hepatitis B e antigen (HBeAg) was detected by RIA in 130 (41.3%) of 315 HBsAg-positive samples. The distribution of HBsAg subtypes by EIA was 190 adr (60.3%), 111 ayw (35.2%), and 14 (0.4%) other subtypes. The HBeAg prevalence decreased with age in all groups for each subtype. There were no significant differences in the prevalence of HBeAg among HBsAg subtypes. We conclude that HBV infection is highly endemic in selected Solomon Islands populations, and that the high prevalence of HBeAg may be associated with the spread of HBV infection there.
Anti-arthropod saliva antibodies among residents of a community at high risk for Lyme disease in California.
Authors: Lane R S , Moss R B , Hsu Y P , Wei T , Mesirow M L , Kuo M M
Published: May 2017

The role of the western black-legged tick (Ixodes pacificus) versus that of other potential arthropod vectors in the epidemiology of Lyme disease was evaluated by determining the prevalence of anti-arthropod saliva antibodies (AASA) among residents (n = 104) of a community at high-risk (CHR). Salivary gland extracts prepared from I. pacificus, the Pacific Coast tick (Dermacentor occidentalis), the western cone-nose bug (Triatoma protracta), and the western tree-hole mosquito (Aedes sierrensis) were used as antigens in an ELISA. Sera from 50 residents of the San Francisco Bay region in northern California and 51 residents of Imperial County in southern California served as comparison groups. The prevalence of AASA ranged from 2% for A. sierrensis to 79% for I. pacificus in study subjects, 0% for D. occidentalis to 36% for I. pacificus among residents of the San Francisco Bay region, and 6% for I. pacificus to 24% for A. sierrensis in residents of Imperial County. The associations between AASA and demographic factors, potential risk factors, probable Lyme disease, and seropositivity for Borrelia burgdorferi were assessed for 85 members of the CHR. Seropositivity for I. pacificus and B. burgdorferi were significantly correlated, the relative risk of seropositivity to B. burgdorferi was about 5 (31% versus 6%) for subjects who were seroreactive to I. pacificus, nearly every individual who was seropositive for B. burgdorferi had elevated levels of antibodies to I. pacificus, and the mean titer for antibodies to I. pacificus was significantly higher for subjects seropositive versus those seronegative for B. burgdorferi. Together, these findings support the widely held belief that I. pacificus is the primary vector of B. burgdorferi for humans in northern California, and they demonstrate the utility of the AASA method as an epidemiologic tool for studying emerging tick-borne infections.
Norwalk-like virus and bacterial pathogens associated with cases of gastroenteritis onboard a US Navy ship.
Authors: Oyofo B A , Soderquist R , Lesmana M , Subekti D , Tjaniadi P , Fryauff D J , Corwin A L , Richie E , Lebron C
Published: May 2017

Acute gastroenteritis is a potential cause of substantial morbidity in U.S. military personnel during deployment. This study investigated the microbial causes of diarrhea in U.S. troops on exercises in Southeast Asia aboard the U.S.S. Germantown from March through May 1996. A total of 49 (7%) patients with diarrhea reported to sick call during a 3-month deployment involving 721 personnel. Diarrheal samples from 49 patients were subjected to bacterial and parasitologic examination, but sufficient samples from only 47 of 49 were available for analysis of the presence of Norwalk-like virus (NLV). Of the 49 diarrhea cases, 10 (20.4%) appeared to be due to bacterial etiology alone, 10 (20.4%) due to bacteria and the prototype Taunton agent (TNA), 11 (22.4%) due to TNA only, and 4 (8.0%) due to parasites. Norwalk-like virus RNA was present in 21 (45%) of 47 stool samples from the diarrhea cases, 10 with bacterial etiologies and 11 without bacterial or parasitic etiologies. No pathogen was detected in 14 (29%) of the cases. Four of the controls showed the presence of parasitic organisms. Of the 11 cases in which enterotoxigenic Escherichia coli was isolated, 8 were positive for colonization factor antigen (CFA/IV), and 3 were CFA-negative. The bacterial pathogens tested were all susceptible to gentamicin, and furadantin, but were resistant to ceftriaxone and norfloxacin, including 75% of the Campylobacter spp. These data support the view that the major cause of diarrhea for troops deployed in this geographic area is most likely NLVs.
Environmental conditions favoring bat infection with Histoplasma capsulatum in Mexican shelters.
Authors: Taylor M L , ChÃ¡vez-Tapia C B , Vargas-YaÃ±ez R , RodrÃ­guez-Arellanes G , PeÃ±a-Sandoval G R , Toriello C , PÃ©rez A , Reyes-Montes M R
Published: May 2017

Histoplasma capsulatum was isolated from gut, lung, liver, and spleen of 17 of 208 captured bats belonging to 6 different genera and species. Three of the 17 infected bats were from the State of Guerrero and 14 were from the State of Morelos. All were adult bats: 6 males (1 Pteronotus parnellii, 2 Natalus stramineus, 2 Artibeus hirsutus, and 1 Leptonycteris nivalis) and 11 females (1 Myotis californicus, 1 Mormoops megalophylla, 8 A. hirsutus, and 1 L. nivalis). High rates of bat infection with H. capsulatum were found in the monitored sites of the State of Morelos. Histoplasma infection of N. stramineus, A. hirsutus, and L. nivalis should be considered as the first records in the world. The fungus isolated from infected bats was identified by its typical mycelial-phase morphology and by its yeast-phase conversion. Exoantigen production confirmed the fungal identification by the presence of specific precipitation lines in double immunodiffusion assays using human immune serum. Histopathologic studies showed intracellular yeast-like cells compatible with H. capsulatum yeast-phase in tissues of several bats, especially in pulmonary (intra-alveolar and septal) macrophages, with none or minimal tissue reaction. In contrast to past reports, present data support a high risk of bat infection with H. capsulatum in Mexican cave environments.
Isolation and genetic characterization of a hantavirus (Bunyaviridae: Hantavirus) from a rodent, Oligoryzomys microtis (Muridae), collected in northeastern Peru.
Authors: Powers A M , Mercer D R , Watts D M , Guzman H , Fulhorst C F , Popov V L , Tesh R B
Published: May 2017

This paper describes the isolation and partial genetic characterization of a hantavirus from a pygmy rice rat, Oligoryzomys microtis, collected within the urban area of Iquitos, Loreto Department, Peru. The virus, designated HTN-007, exhibited the highest degree of genetic similarity to Rio Mamore virus, which was originally described from the same rodent species in eastern Bolivia. Comparison of small and medium segment nucleotide sequence data from HTN-007 and Rio Mamore virus revealed 87% and 85% sequence identity, respectively. Based on these analyses, HTN-007 appears to be a variant of Rio Mamore virus. As such, it represents the first successful isolation of Rio Mamore virus and the first evidence for the existence of a hantavirus in Peru. Serologic studies done by immunofluorescence on blood samples of 56 O. microtis trapped at the collection site indicated that 21.4% had antibodies to hantavirus. In view of the proximity of this rodent species to humans and the close phylogenetic relationship of Rio Mamore virus to hantaviruses that have been associated with human disease, Rio Mamore virus may be a hantavirus of some public health importance in tropical South America.
Infectious and tropical diseases in Oman: a review.
Authors: Scrimgeour E M , Mehta F R , Suleiman A J
Published: May 2017

Oman is generally hot and dry, but the Salalah region in southern Dhofar province is relatively cool and rainy during the summer monsoon, and has a distinctive pattern of infection. Important, notifiable infections in Oman include tuberculosis, brucellosis (endemic in Dhofar), acute gastroenteritis, and viral hepatitis: 4.9% of the adults are seropositive for hepatitis B surface antigen and approximately 1.2% for hepatitis C virus. Infection with human immunodeficiency virus is uncommon, and leprosy, rabies, and Crimean-Congo hemorrhagic fever are rare. Between 1990 and 1998, the incidence of malaria, (>70% due to Plasmodium falciparum) decreased from 32,700 to 882 cases. Cutaneous and visceral leishmaniasis (caused by Leishmania tropica and L. infantum, respectively) and Bancroftian filariasis occur sporadically. Intestinal parasitism ranges from 17% to 42% in different populations. A solitary focus of schistosomiasis mansoni in Dhofar has been eradicated. There are major programs for the elimination of tuberculosis, leprosy, and malaria, and to control brucellosis, leishmaniasis, sexually transmitted diseases, trachoma, acute respiratory infection in children, and diarrheal diseases. The Expanded Program on Immunization was introduced in 1981: diphtheria, neonatal tetanus, and probably poliomyelitis have been eliminated.
Analysis of repeated hemoglobin measures in full-term, normal birth weight Kenyan children between birth and four years of age. III. The Asemobo Bay Cohort Project.
Authors: McElroy P D , Lal A A , Hawley W A , Bloland P B , Kuile F O , Oloo A J , Harlow S D , Lin X , Nahlen B L
Published: May 2017

Anemia is an important public health problem. During very early childhood numerous factors affect hemoglobin (Hb) concentration over time, making single cross-sectional measurements difficult to interpret when studying the natural history of anemia or evaluating anemia control strategies. We analyzed repeated Hb measures contributed by 942 Kenyan children between birth and 48 months of life using a mixed effects model, with a regression spline used to describe the population mean Hb profile, and random intercepts and slopes and first-order autoregressive correlation structure to accommodate the within-individual correlation among the repeated Hb measures. The approach facilitates the study of time-stationary and time-varying covariates that influence Hb in early life. The fitted mean Hb profile obtained from the analytic model is consistent with the observed mean Hb of the study population. Village of residence was associated with greatest difference in mean Hb at time of birth (16 versus 19 g/dL; P < 0.0001). Monthly weight-for-age was also associated with mean Hb after 3 months of age. This is the first description of an analysis strategy specifically for repeated Hb measures collected in a longitudinal field study in Africa. The strategy will facilitate improved study of time-varying covariates thought to influence pediatric anemia.
No evidence of cardiotoxicity during antimalarial treatment with artemether-lumefantrine.
Authors: van Vugt M , Ezzet F , Nosten F , Gathmann I , Wilairatana P , Looareesuwan S , White N J
Published: May 2017

Artemether-lumefantrine is a new fixed antimalarial combination effective against multidrug-resistant falciparum malaria. A prospective electrocardiographic study was conducted in 150 patients receiving artemetherlumefantrine and 50 treated with artesunate-mefloquine. There was no evidence for clinically significant changes in the electrocardiographic intervals and in particular no relationship between plasma concentrations of lumefantrine and QTc prolongation. Artemether-lumefantrine does not have significant cardiac effects at therapeutic doses.
Genetic structure and phylogenetic relationships of Colombian Trypanosoma cruzi populations as determined by schizodeme and isoenzyme markers.
Authors: Jaramillo N , Moreno J , Triana O , Arcos-Burgos M , MuÃ±oz S , Solari A
Published: May 2017

Twenty-four Trypanosoma cruzi stocks isolated from vectors and from human and Didelphis marsupialis hosts from highly separated sylvatic localities in Colombia were characterized by isoenzyme and schizodeme analyses. The stocks were collected primarily from sylvatic ecotopes representing areas of low, moderate, and high endemicity for Chagas' diseases in Colombia. Parasites were characterized mainly by schizodeme analysis with the restriction enzyme Eco RI and the isoenzyme analysis was performed at 10 genetic loci. These analyses demonstrated an agreement between the classifications based on the isoenzyme analysis and on the restriction fragment length polymorphism patterns obtained with the Colombian stocks. There is clear evidence of demic subdivision between the eastern (E) and western (W) stocks separated by the Andean Mountains and Magdalena River, which is likely due to the geographic isolation generated by these topographic features. Heterozygosity estimates indicate that the E group could be more ancient than the W group. As was postulated in a previous study, these results are also compatible with the existence of a clonal population structure in Colombian sylvatic T. cruzi. Evidence presented here failed to demonstrate a correlation between the degree of endemy and genetic clustering. Finally, schizodeme and isoenzymatic analyses comparing Colombian T. cruzi stocks with others from Chile confirm that Colombian isolates are genetically related to zymodeme 1 and distant from zymodeme 2.
Different prevalences of Plasmodium vivax phenotypes VK210 and VK247 associated with the distribution of Anopheles albimanus and Anopheles pseudopunctipennis in Mexico.
Authors: Rodriguez M H , Gonzalez-Ceron L , Hernandez J E , Nettel J A , Villarreal C , Kain K C , Wirtz R A
Published: May 2017

The geographic distribution of Plasmodium vivax circumsporozoite protein phenotypes from patient blood used to infect colonized Anopheles albimanus and An. pseudopunctipennis was investigated in southern Mexico. Parasite phenotype types were determined in blood samples by a polymerase chain reaction and oligoprobe hybridization or by immunofluorescent assay of sporozoites. The proportion of infected mosquitoes and the number of oocysts per mosquito confirmed previous in vitro observations indicating that An. albimanus is more susceptible to VK210 and that An. pseudopunctipennis is more susceptible to VK247. All patients living on the coast were infected with VK210 and most patients living above 170 meters above sea level had VK247. Both phenotypes infected patients from intermediate altitudes. These results concur with the distribution of the anophelines, indicating that An. albimanus is the main vector of the phenotype VK210, but that An. pseudopunctipennis transmits both phenotypes. These conditions have direct implications on parasite transmission rates and malaria epidemiology in Mexico.
Epidemiologic tools for malaria surveillance in an urban setting of low endemicity along the Colombian Pacific coast.
Authors: Carrasquilla G , Banguero M , Sanchez P , Carvajal F , Barker R H , Gervais G W , Algarin E , Serrano A E
Published: May 2017

An evaluation of 3 different methods for malaria diagnosis was carried out in an urban area of low endemicity on the Pacific coast of Colombia. Samples were collected from 833 symptomatic patients at a malaria clinic and examined by the polymerase chain reaction (PCR), quantitative buffy coat (QBC; Becton Dickinson, Franklin Lakes, NJ) method, and the traditional thick blood smear. The prevalence of Plasmodium falciparum malaria was 5.88% by thick blood smear, 7.34% by the QBC method, and 21.87% by PCR. The agreement between microscopists was 99.5%. The agreement between the QBC method and thick blood smear was 96.13% (n = 745). Samples positive by PCR but negative by thick blood smear or conversely negative by PCR and positive by thick blood smear were usually of low-level parasitemias. All 3 methods showed agreement in 76.3% of the samples. Sixty-nine (18.8%) samples were positive by PCR but negative by the other 2 methods. Ten samples were positive by both the QBC method and thick blood smear but negative by PCR; most of them had low-level parasitemias. The use of malaria diagnostic methods for epidemiologic surveillance is discussed.
Short report: isolation and identification of two spotted fever group rickettsial strains from patients in Catalonia, Spain.
Authors: CardeÃ±osa N , Roux V , Font B , Sanfeliu I , Raoult D , Segura F
Published: May 2017

Two rickettsial strains, 16B (previously isolated) and FB1, were isolated from blood from patients with Mediterranean spotted fever in Catalonia, Spain. These are the only 2 human rickettsial isolates of the spotted fever group obtained so far in Spain. These strains were identified by the polymerase chain reaction and sequence analysis of a fragment of the outer membrane protein A (ompA) gene. The partial ompA sequence was found to be 100% identical with that of Rickettsia conorii (Malish 7 strain) for both strains. These results confirm the presence of R. conorii in Catalonia, despite the fact that in a previous study, no R. conorii were isolated, but a new rickettsial strain of the spotted fever group (Bar29) was isolated from dog ticks (Rhipicephalus sanguineus) in Catalonia. Further studies are necessary to get a better knowledge of the epidemiology of rickettsiae in Catalonia.
Vertical transmission of the yellow fever virus by Aedes aegypti (Diptera, Culicidae): dynamics of infection in F1 adult progeny of orally infected females.
Authors: Diallo M , Thonnon J , Fontenille D
Published: May 2017

Vertical transmission of yellow fever virus from orally infected females to their progeny was experimentally demonstrated in 2 Aedes aegypti colonies from the Dakar and Koungheul regions in Senegal. A total of 10,530 F1 adult mosquito progeny were tested. The overall vertical transmission rate was 0.97%, with no significant difference between the Dakar and Koungheul colonies. The infection rates were significantly higher in females (1.15%) than in males (0.74%) in both colonies. The virus was not isolated from the progeny of the first oviposition cycle (OVC1). The true infection rates were 0.27% and 1.99%, respectively, for the OVC2 and OVC3 progeny in the Dakar colony, and 1.1% and 1.48%, respectively, for the OVC2 and OVC3 progeny in the Koungheul colony. The infection rates increased with extrinsic incubation in both male and female offspring of the 2 colonies, reaching 5.2% in 20-day-old OVC3 female progeny in the Dakar colony. The epidemiologic consequences of these results are discussed.
Identification of morphologically similar Rhodnius species (Hemiptera: Reduviidae: Triatominae) by electrophoresis of salivary heme proteins.
Authors: Soares R P , Sant'Anna M R , Gontijo N F , Romanha A J , Diotaiuti L , Pereira M H
Published: May 2017

We examined intraspecific variability in the genus Rhodnius using starch gel electrophoresis of salivary heme proteins. Salivary protein profiles of 8 Rhodnius species (R. prolixus, R. robustus, R. neglectus, R. nasutus, R. ecuadoriensis, R. pallescens, R. pictipes, and R. domesticus) were compared. All species could be distinguished by this technique. The greatest protein polymorphism was found in R. ecuadoriensis, R. nasutus, R. robustus, and R. pictipes, followed by R. prolixus, R. neglectus, R. pallescens, and R. domesticus. This approach was able to distinguish R. prolixus from R. robustus and R. neglectus from R. nasutus, species with extreme phenotypical similarity.
Dracunculiasis eradication: delayed, not denied.
Authors: Hopkins D R , Ruiz-Tiben E , Ruebush T K , Diallo N , Agle A , Withers P C
Published: May 2017

By the end of 1998, Asia was free of dracunculiasis (Guinea worm disease), with Pakistan, India, and Yemen having interrupted transmission in 1993, 1996, and 1997, respectively. Transmission of the disease was also interrupted in Cameroon and Senegal during 1997. Chad reported only 3 cases during 1998. Dracunculiasis is now confined to only 13 countries in Africa. The overall number of cases has been reduced by more than 97% from the 3.2 million cases estimated to have occurred in 1986 to 78,557 cases reported in 1998. Because the civil war in Sudan remains the major impediment to eradication of dracunculiasis, the interim goal is to stop all transmission outside that country by the end of 2000. The most important operational need now is for national programs to improve the frequency and quality of supervision of village-based health workers in order to enhance the sensitivity of surveillance and effectiveness of case containment.
The epidemiology of schistosomiasis in Egypt: methods, training, and quality control of clinical and ultrasound examinations.
Authors: Abdel-Wahab M F , Esmat G , El-Boraey Y , Ramzy I , Medhat E , Strickland G T
Published: May 2017

Morbidity due to schistosomiasis was evaluated in a subpopulation of 14,000 of the randomized sample in the Epidemiology 1, 2, 3 Project. It was measured by using a standardized questionnaire for obtaining medical history and symptoms and by performing standardized physical and ultrasound examinations. Reported herein are descriptions of the methods and training and quality control efforts made to insure that the morbidity data was reliable and consistent when collected by 7 different teams in 9 different governorates.
The epidemiology of schistosomiasis in Egypt: patterns of Schistosoma mansoni infection and morbidity in Kafer El-Sheikh.
Authors: Barakat R , Farghaly A , El Masry A G , El-Sayed M K , Hussein M H
Published: May 2017

This is a descriptive report of the Epidemiology 1, 2, 3 project in Egypt that made use of large probability sampling methods. These results focus on Schistosoma mansoni infection in the northern Nile Delta governorate of Kafr El Sheikh. A probability sample of 18,777 persons, representing the rural population of the entire governorate, was drawn. The sample was designed not to exclude villages based on location or presence of health care facilities and to include representation of the smaller ezbas or hamlets. The objective was to obtain detailed estimates on age- and sex-specific patterns of S. mansoni infection, and to provide a baseline for prospective studies. Stool specimens were examined by the Kato method. The estimated mean +/- SE prevalence of S. mansoni infection in the rural population was 39.3 +/- 3.3% in 44 villages and ezbas after weighing for the effects of the sample design. The estimated mean +/- SE geometric mean egg count per gram of stool (GMEC) was 72.9 +/- 7.3. Prevalence and GMEC varied considerably by village and ezba, with ezbas having a significantly higher prevalence. Villages and ezba-specific prevalence was strongly associated with GMEC (r2 = 0.61, P < 0.001). The prevalence of S. mansoni infection increased by age to 55.4 +/- 3.2% at age 16 without a significant change in the adult ages. There were no gender differences until age 6, after which males were consistently higher until middle age, when the differences converged. The age- and sex-specific pattern of GMEC varied widely; however, when the GMEC data were collapsed into 5-year age groups, the GMEC peaked at 81.5 +/- 12.1 eggs/g in the 10-14-year-old age group. These estimates provide the basis for evaluating control measures for reducing prevalence, intensity of infection, and transmission.
Gametocytemia and infectivity to mosquitoes of patients with uncomplicated Plasmodium falciparum malaria attacks treated with chloroquine or sulfadoxine plus pyrimethamine.
Authors: Robert V , Awono-Ambene H P , Le Hesran J Y , Trape J F
Published: May 2017

Plasmodium falciparum gametocytemia and its related infectivity for mosquitoes was studied in 115 patients (median age = 18 years, range = 4-45) with simple malaria attacks who lived in the hypoendemic area of Dakar, Senegal. Patients were included in a 28-day in vivo sensitivity test after treatment with chloroquine (CQ, n = 82) or sulfadoxine plus pyrimethamine (SP, n = 33). The prevalence of resistant infections was 58.5% in those treated with CQ and 0% in those treated with SP. The gametocytemia peaked at day 7 after treatment. The maximal gametocyte prevalence was 38.2% in the CQ-sensitive infection group, 89.6% in the CQ-resistant group, and 97.0% in those treated with SP The maximal geometric mean gametocytemia was 2.19/microl in the CQ-sensitive infection group, 29.12/microl in the CQ-resistant group and 85.55/microl in those treated with SP. The period between appearance of the first clinical symptom and treatment was positively related to gametocyte prevalence at days 0 and 2. Experimental infection of wild Anopheles arabiensis using membrane feeders was performed at days 0 and 7, and mosquito infectivity was measured by oocyst detection on the midgut. At day 0, 14.1% of the patients had infected at least 1 mosquito, and at day 7, this value was 38.5%. The mean percentage of infected mosquitoes was 3.2% at day 0 and 12.6% at day 7. At day 7 after treatment with CQ, the relative risk for patients with resistant infections of infecting anophelines was 4.07 higher than in those with sensitive infections. No difference was observed in infectivity for mosquitoes between RI-type resistance and the RII + RIII-type resistance. A sporonticidal effect of SP was observed at day 7 after treatment. These data show that P. falciparum gametocytes and their infectivity for mosquitoes were differentiated according to the drug used, its efficacy, and the duration of symptoms before treatment; they were not dependent on the density of asexual stages. Prompt treatment of malaria cases performed at the beginning of symptoms could limit the spread of resistant parasites.
The epidemiology of malaria in an epidemic area of the Peruvian Amazon.
Authors: Roper M H , Torres R S , Goicochea C G , Andersen E M , Guarda J S , Calampa C , Hightower A W , Magill A J
Published: May 2017

A longitudinal study of malariometric indicators and their association with potential risk factors was conducted during August 1997-July 1998 at Padre Cocha, a village of 1,400 residents in the Peruvian Amazon. The incidence of Plasmodium falciparum infections during the study year was 166/1,000 persons; that of P. vivax was 826/1,000 persons. The mean duration of symptoms prior to diagnosis was 2 days; presenting geometric mean parasite densities were 3,976 parasites/microl for P. falciparum infections and 2,282 parasites/microl for P. vivax. There were no malaria-associated deaths. Consistent with the epidemic nature of malaria in the area, the incidence of both parasite species increased with age and there were no age-specific differences in mean parasite densities. No specific occupational risks for malaria were identified. Activities significantly associated with malaria risk reflected local vector behavior and included strolling outdoors after 6:00 PM and arising before 6:00 AM for adults, and attending evening church services for children.
Hepatitis C virus genotypes in a northeastern area of Brazil.
Authors: Silva L K , ParanÃ¡ R , Souza S P , Berby F , Kay A , TrepÃ³ C , Santana N , Cotrim H , Lyra L G , Reis M G
Published: May 2017

We used a reverse transcription-polymerase chain reaction (RT-PCR) to obtain the genotypes of circulating hepatitis C virus (HCV) in patients from a Gastro-Hepatology Unit in the city of Salvador (Bahia State) in northeastern Brazil. Viral RNA was detected in 83 (65.4%) of 127 anti-HCV seropositive serum samples. Positivity was significantly associated with alterations in levels of aspartate aminotransferase and alanine aminotransferase (P < 0.05). Genotyping of HCV was performed by RT-PCR using genotype-specific primers from the core region: 24.1% were infected with subtype 1a, 38.6% with 1b, 3.6% with 2, 21.7% with 3a, and 12.0% with a mixed genotype. There was no difference in genotype distribution when compared with results from other Brazilian locations. Surprisingly, the high frequency of genotype 3 in Brazilian samples continues to be different from that reported around the world and warrants further investigation.
Detection of DNA of nocturnally periodic Brugia malayi in night and day blood samples by a polymerase chain reaction-ELISA-based method using an internal control DNA.
Authors: Fischer P , Supali T , Wibowo H , Bonow I , Williams S A
Published: May 2017

An internal control was used in a polymerase chain reaction (PCR)-ELISA-based technique to detect the Hha I repeat of the filarial parasite Brugia malayi. A single microfilaria added to 200 microl of blood was reliably detected. The assay was evaluated on field samples from persons living in an area endemic for Anopheles-transmitted, nocturnally periodic B. malayi in central Sulawesi, Indonesia. Examination of night blood of 138 individuals for the presence of microfilariae by filtration revealed 44 microfilaria carriers. All microfilaria carriers were also positive in the PCR-ELISA and, in addition, 14 more samples were proven to contain parasite DNA. The sensitivity of both methods was compared on night and on day blood samples collected from 113 persons. Whereas 37 microfilaria carriers were identified by filtration of night blood, no microfilariae were observed in the corresponding day blood samples. The PCR-ELISA result was positive in all 37 night blood samples of microfilaria carriers and in an additional 13 night blood samples without microfilariae. Parasite DNA was detected in 31 day blood samples of microfilaria carriers and in 3 day blood samples of amicrofilaremic persons. Assuming a sensitivity of the PCR-ELISA on night blood of 100%, the sensitivity of night blood filtration is 74% and that of the PCR-ELISA on day blood is 68%. These data suggest that the described PCR-ELISA method is capable of detecting infections with nocturnally periodic B. malayi in day blood samples. Therefore, this method may facilitate both the identification of endemic areas and the monitoring of control programs.
Diagnostic and prognostic value of an immunofluorescent assay for melioidosis.
Authors: Vadivelu J , Puthucheary S D
Published: May 2017

Melioidosis caused by Burkholderia pseudomallei is endemic in southeast Asia. The clinical manifestations range from wound infections to acute septicemia. In some cases, recurrence can also occur following complete recovery. Case fatality rates are high and a major factor is the delay in the culture and identification of the bacterium. An immunofluorescent assay (IFAT) using whole-cell antigen for the detection of total antibodies to B. pseudomallei was tested with 650 sera. Using a cut-off value of 1:80, 66 sera from culture-confirmed cases were positive with titers > or = 320. In another 523 sera from patients in which no other etiology could be found, 149 (23.4%) were positive. To monitor disease activity, persistence of antibody levels was investigated on 61 serial sera samples collected from 14 other confirmed cases on follow-up visits while on oral maintenance therapy. The IFAT demonstrated a reduction in titers in cases of localized infections, suggesting that either the infection was being resolved or arrested while septicemic patients maintained high IFAT titers on follow-up, suggesting the possibility of continuous sequestration of antigen from an intracellular source.
Evaluation of rapid diagnostic tests for the detection of human immunodeficiency virus types 1 and 2, hepatitis B surface antigen, and syphilis in Ho Chi Minh City, Vietnam.
Authors: Lien T X , Tien N T , Chanpong G F , Cuc C T , Yen V T , Soderquist R , Laras K , Corwin A
Published: May 2017

An evaluation of three new rapid diagnostic test kits for human immunodeficiency virus types 1 and 2 (HIV-1/2), hepatitis B surface antigen (HBsAg), and syphilis involved a two-phase comparison of rapid diagnostic assays using prospectively collected from hospitals and clinics in Ho Chi Minh City, Vietnam. After specificity and sensitivity testing, three new rapid diagnostic test kits were tested in parallel with six commonly used diagnostic test kits. The Determine HIV-1/2 test had fewer indeterminate or equivocal results than the Capillus HIV-1/HIV-2 or HIV Blot 2.2 tests. However, the Determine HIV-1/2 test yielded one false-positive result when compared with the Serodia HIV, HIV Blot 2.2, and microparticle enzyme immunoassay (IMx) HIV tests. The Serodia HBsAg test yielded more false-negative results when compared with the Determine HBsAg diagnostic test kit. The results of the syphilis diagnostic tests evaluated in this clinical trial consistently agreed with those of the rapid plasma reagin test for syphilis. The Determine Syphilis Treponema pallidum (TP) test had three false-positive results compared with the Serodia TP and the Serodia TP x particle agglutination (PA) tests, which had two false-positive results that were confirmed as negative by an ELISA. Application of these serologic tests within this comparative evaluation framework, using the World Health Organization alternative testing strategies, proved to be an effective way to determine serostatus related to HIV, hepatitis B, and syphilis.
Detection of Francisella tularensis in infected mammals and vectors using a probe-based polymerase chain reaction.
Authors: Higgins J A , Hubalek Z , Halouzka J , Elkins K L , Sjostedt A , Shipley M , Ibrahim M S
Published: May 2017

We investigated the use of a TaqMan 5' nuclease assay (5NA) directed against the Francisella tularensis outer membrane protein (Fop) gene and a polymerase chain reaction-enzyme immunoassay (PCR-EIA) directed against the tul 4 gene for detection of this organism in experimentally infected mice and in field-collected tick vectors. We also evaluated the use of specially formulated filter paper (FTA) for rapid sample preparation. The 5NA had a detection limit of 1 pg of genomic DNA (<100 colony-forming units) and could be completed within several hours. The PCR-EIA could detect 1 pg of genomic DNA and 10 attograms (ag) (22 copies) of cloned insert, but takes longer to perform. Both assays were genus-specific, and successfully detected F. tularensis in mouse tissues (5NA) and in tick extracts (PCR-EIA). The FTA paper provided inexpensive, rapid, template preparation for the tick extracts, mouse tissues, and DNA obtained from clinical specimens. These probe-based assays have the potential to provide rapid, real-time/high-throughput molecular diagnostics in field situations.
Immunohistochemical characterization of the inflammatory infiltrate in placental Chagas' disease: a qualitative and quantitative analysis.
Authors: Altemani A M , Bittencourt A L , Lana A M
Published: May 2017

Chagas' disease, a systemic illness endemic to some regions of South America, is caused by the protozoan Trypanosoma cruzi. Transplacental infection may occur during any phase and cause fetal death. This study is the first to characterize the inflammatory cells in chagasic villitis by immunohistochemistry. Paraffin sections of 8 placentas with villitis by T. cruzi (4 live births and 4 stillbirths), as well as 8 control placentas without inflammation, were stained with hematoxylin and eosin, monoclonal antibodies for CD45RO, CD20, CD45RO/OPD4, CD8, HNKI, CD15, MAC387, and CD68 proteins, and a polyclonal antibody for S-100 protein. Quantification of positive cells was performed in 3 different high-power fields. In all cases of chagasic villitis, the inflammatory infiltrate was composed mainly of CD68+ macrophages, T lymphocytes, and a few natural killer cells. Among T cells, CD8+ cells outnumbered CD4+ cells in all placentas (CD4+:CD8+ ratios ranged from 0.04 to 0.38). B cells were absent or rare. In stillbirths, villitis was diffuse and severe with numerous T. cruzi, while in live births it was focal with few parasites. Other features that characterized villitis in stillbirths were 1) frequent trophoblastic necrosis, 2) presence of MAC387+ macrophages and CD15+ granulocytes attached to the sites of trophoblastic necrosis, 3) low CD4+: CD8+ ratios in most cases, 4) increased numbers of S-100 positive cells in the villous stroma. In conclusion, CD68+ macrophages and CD8+ T lymphocytes were the major cell population in villitis caused by T. cruzi. However, the pattern of inflammatory reaction differed between stillbirths and live births and was probably related to the number of parasites in the placental villi.
Risk factors for Echinococcus granulosus infection: a case-control study.
Authors: Campos-Bueno A , LÃ³pez-Abente G , AndrÃ©s-Cercadillo A M
Published: May 2017

Despite the importance of cystic hydatid disease worldwide, no case-control study evaluating the risk factors for Echinococcus granulosus infection has been published to date. Thus, we carried out a hospital study to quantify different risk factors associated with the disease in a province marked by a high incidence of hydatidosis (Soria, Spain). The study population was composed of 127 cases and 127 controls matched by sex, age, and residence. Odds ratios (ORs) for hydatidosis decreased inversely with size of place of birth and residence, and increased with the number of dogs and years of coexistence with them. The variable involving the possibility of dogs ingesting uncooked viscera or carrion proved to be of greater importance (OR = 3.99, 95% confidence interval = 1.94-8.20). Risk factors for hydatidosis traceable to the family environment are of greater relative importance than those attributable to working directly with livestock. No association could be found between ingestion of raw green vegetables and hydatidosis.
Invasive bacterial infections of children in a rural province in the central Philippines.
Authors: Lupisan S P , Herva E , Sombrero L T , Quiambao B P , Capeding M R , Abucejo P E , Esparar G , Arcay J , Ruutu P
Published: May 2017

The etiology of invasive bacterial infections was studied among 956 Filipino children less than five years old who fulfilled the World Health Organization criteria for severe or very severe pneumonia or had suspected meningitis or sepsis. The most common invasive infections were due to Streptococcus pneumoniae (12 [1.3%]) and Haemophilus influenzae (12 [1.3%]); including four cases of pneumococcal meningitis and 11 cases of H. influenzae meningitis. Type 1 was the most common (six of the 12 isolates) of the pneumococcal serotypes. Serotypes/groups 1, 6, 14, and 23 accounted for 91.7% of the invasive isolates. The majority of the H. influenzae strains from blood (10 out of 10) and cerebrospinal fluid (6 out of 7) were type b. Almost all of the invasive S. pneumoniae (9 out of 12) and H. influenzae (11 out of 12) infections were seen before one year of age, which stresses the need to investigate early immunization of children for H. influenzae type b and S. pneumoniae, as well as maternal immunization to maximize the potential of immunoprophylaxis.
Long-term effects of a nationwide control program on the seropositivity for Trypanosoma cruzi infection in young men from Argentina.
Authors: Segura E L , Cura E N , Estani S A , Andrade J , Lansetti J C , de Rissio A M , Campanini A , Blanco S B , GÃ¼rtler R E , Alvarez M
Published: May 2017

Unselected nationwide cohorts of Argentine men 18 years of age summoned for military service were tested for antibodies to Trypanosoma cruzi each year from 1981 to 1993. After an initial screening using indirect hemagglutination test, the positive sera were retested by titrated indirect hemagglutination and immunofluorescence antibody tests at 39 laboratories or at the national reference center in Buenos Aires. Nearly 1.8 million men were examined for T. cruzi antibodies using the same standardized procedures under a quality assurance program. The prevalence of seropositivity for T. cruzi decreased significantly from 5.8% in 1981 to 1.9% in 1993, but the decrease was not homogeneous among provinces within each region or constant over time. Prior to the nationwide control campaign initiated in 1961-1962, 15 provinces had high (> 20%) percentages of houses with domiciliary infestation by Triatoma infestans bugs, which decreased to nine provinces in 1982, and four provinces in 1992. The observed decrease in the prevalence of seropositivity for T. cruzi may be mostly attributed to the spraying with insecticides to eliminate the domiciliary populations of Triatoma infestans. The lack of a sustainable triatomine surveillance program set a limit to the decrease of seropositivity rates and prompted a revised strategy based on community participation.
Contrasting functions of IgG and IgE antimalarial antibodies in uncomplicated and severe Plasmodium falciparum malaria.
Authors: Perlmann P , Perlmann H , Looareesuwan S , Krudsood S , Kano S , Matsumoto Y , Brittenham G , Troye-Blomberg M , Aikawa M
Published: May 2017

Plasmodial infection results in a significant elevation of the blood concentrations of immunoglobulins including IgE. Two well-characterized groups of adult Thai patients with either uncomplicated or severe Plasmodium falciparum malaria were studied over a period of four weeks. The mean parasitemias were approximately three-fold higher in patients with severe malaria than in those with uncomplicated disease. The mean concentrations of both total IgG and IgG antiplasmodial antibodies tended to be highest in the group with uncomplicated disease while total IgE and IgE antibodies were higher in the group with severe disease. The IgE antibodies detected in approximately 65% of the patients were positively correlated to parasitemia. These results suggest that antiplasmodial IgG antibodies are involved in reducing the severity of P. falciparum malaria, while IgE antibodies may contribute to the pathogenesis of this infection.