High-risk behaviors for hepatitis B and C infections among female sex workers.

INTRODUCTION: The prevalence of hepatitis B and hepatitis C and risk behaviors among 402 female sex workers in Central Brazil were investigated by respondent-driven sampling. METHODS: Blood samples were tested for hepatitis B and C markers by enzyme-linked immunosorbent assay. Two hepatitis B vaccination schedules were performed. RESULTS: The prevalence of hepatitis B and C infections were 9.3% and 0.5%, respectively. Susceptibility to hepatitis B infection was observed in 61.5% of subjects. There was no significant difference in adherence index (p=0.52) between vaccination schedules and all participants had protective antibody titers. CONCLUSIONS: This hard-to-reach population requires hepatitis B and C surveillance.

High-risk behaviors for hepatitis B and C infections among female sex workers

Abstract INTRODUCTION: The prevalence of hepatitis B and hepatitis C and risk behaviors among 402 female sex workers in Central Brazil were investigated by respondent-driven sampling. METHODS: Blood samples were tested for hepatitis B and C markers by enzyme-linked immunosorbent assay. Two hepatitis B vaccination schedules were performed. RESULTS: The prevalence of hepatitis B and C infections were 9.3% and 0.5%, respectively. Susceptibility to hepatitis B infection was observed in 61.5% of subjects. There was no significant difference in adherence index (p=0.52) between vaccination schedules and all participants had protective antibody titers. CONCLUSIONS: This hard-to-reach population requires hepatitis B and C surveillance.

Enteroparasites in Riverside Settlements in the Pantanal Wetlands Ecosystem.

BACKGROUND: Intestinal parasites are a major source of health problems in developing countries, where socioeconomic, cultural, and environmental conditions contribute in maintaining the biological cycles of various parasites and facilitating their spread. The objective of this study, conducted in Corumbá, Mato Grosso do Sul state, Brazil, was to investigate the occurrence of intestinal parasites in riverside communities in the South Pantanal wetlands and conduct educational interventions focused on health and environmental preservation. METHOD: In total, 196 stool samples were tested for parasites using the merthiolate-iodine-formaldehyde concentration (MIFC) technique and spontaneous sedimentation and educational activities were carried out. RESULTS: Enteroparasite prevalence was 72% (65.6-78.2%; 95% CI). Of the 141 positive cases, monoparasitism was found in 34.7%, biparasitism in 23%, and polyparasitism in 14.3%. Entamoeba coli was the most frequent protozoan (70.2%). Among helminths, hookworms were the most prevalent. Enteroparasitosis prevalence did not differ for sex or place of abode but proved higher in individuals older than 10 years. CONCLUSION: The high positivity rate for enteroparasites found for the communities stems from lack of sanitation and poor personal and environmental hygiene habits, indicating that effective health policies and educational interventions are needed to reduce the current risk levels.

Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions.

Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L. infantum transmission. Moreover, it was also permissive to L. amazonensis.

Leishmania amazonensis DNA in wild females ofLutzomyia cruzi (Diptera: Psychodidae) in the state of Mato Grosso do Sul, Brazil

Studies on natural infection by Leishmania spp of sandflies collected in endemic and nonendemic areas can provide important information on the distribution and intensity of the transmission of these parasites. This study sought to investigate the natural infection by Leishmaniain wild female sandflies. The specimens were caught in the city of Corumbá, state of Mato Grosso do Sul (Brazil) between October 2012-March 2014, and dissected to investigate flagellates and/or submitted to molecular analysis to detect Leishmania DNA. A total of 1,164 females (77.56% of which were Lutzomyia cruzi) representing 11 species were investigated using molecular analysis; 126 specimens of Lu. cruziwere dissected and also submitted to molecular analysis. The infection rate based on the presence of Leishmania DNA considering all the sandfly species analysed was 0.69%; only Leishmania (Leishmania) amazonensis was identified in Lu. cruzi by the molecular analysis. The dissections were negative for flagellates. This is the first record of the presence of L. (L.) amazonensis DNA in Lu. cruzi, and the first record of this parasite in this area. These findings point to the need for further investigation into the possible role of this sandfly as vector of this parasite.

Leishmania amazonensis DNA in wild females of Lutzomyia cruzi (Diptera: Psychodidae) in the state of Mato Grosso do Sul, Brazil.

Studies on natural infection by Leishmania spp of sandflies collected in endemic and nonendemic areas can provide important information on the distribution and intensity of the transmission of these parasites. This study sought to investigate the natural infection by Leishmaniain wild female sandflies. The specimens were caught in the city of Corumbá, state of Mato Grosso do Sul (Brazil) between October 2012-March 2014, and dissected to investigate flagellates and/or submitted to molecular analysis to detect Leishmania DNA. A total of 1,164 females (77.56% of which were Lutzomyia cruzi) representing 11 species were investigated using molecular analysis; 126 specimens of Lu. cruziwere dissected and also submitted to molecular analysis. The infection rate based on the presence of Leishmania DNA considering all the sandfly species analysed was 0.69%; only Leishmania (Leishmania) amazonensis was identified in Lu. cruzi by the molecular analysis. The dissections were negative for flagellates. This is the first record of the presence of L. (L.) amazonensis DNA in Lu. cruzi, and the first record of this parasite in this area. These findings point to the need for further investigation into the possible role of this sandfly as vector of this parasite.

Cross-Sectional Study of Hepatitis A Virus Infection in the Pantanal Population before Vaccine Implementation in Brazil: Usage of Non-Invasive Specimen Collection.

Population-based prevalence studies are essential tools for screening of hepatitis A and provide important data on susceptible groups. However, surveillance in isolated communities is difficult because of the limited access to these areas and the need for blood sample collection. This study aimed to determine the anti-HAV prevalence using oral fluid samples to provide an alternative tool for epidemiological studies that might be useful for vaccination-related decisions. The study population was composed of 224 volunteers from South Pantanal, aged 3 to 86 years old. This study was performed using oral fluids, previously standardized for anti-HAV antibody detection, which were collected using a ChemBio device. Eluates were tested using modified commercial EIA to detect anti-HAV antibodies. The overall prevalence was 79.1%, corresponding to 178 reactive EIA tests out of 224 samples. The age stratified data revealed a prevalence of 47.8% between 0-10 years, 84% in 11-20 years and 91.9% in subjects older than 21 years. Results indicate that hepatitis A prevalence was higher in adolescents and adults, corroborating the literature reports. Thus, oral fluid samples could replace serum in HAV epidemiological studies in isolated communities as they are efficient at detecting anti-HAV antibodies.

Importance of collection methods and stability of oral fluid samples for hepatitis B surface antigen detection.

BACKGROUND: Oral fluid (OF) sample collection and stability for HBsAg detection are not fully established. This study aims to investigate the applicability of OF collectors and sample stability for Hepatitis B virus surface antigen detection. METHODS: Paired serum and OF samples were obtained from 191 individuals, and Chembio (Chembio Diagnostic System, USA) and Salivette (Sarstedt, Germany) devices were used for OF collection. Two HBsAg enzyme immunoassays (EIAs) were used (HBsAg One kit, Radim, Rome, Italy and ETI-MAK-4, DiaSorin, Vercelli, Italy) to determine the most efficient method according OF collector. Sample volume, incubation time, and cutoff (CO) value were evaluated. The stability of OF samples was determined under different environmental conditions. RESULTS: Chembio samples analyzed using DiaSorin EIA without modification of the manufacturer's instructions, demonstrated a sensitivity of 95.24% and a specificity of 100%. Salivette samples analyzed with Radim EIA with receiver operating characteristic (ROC) curve for calculating the CO showed a sensitivity of 78.26% and a specificity of 89.88%. HBsAg was detected in Chembio and Salivette samples under different environmental conditions, but the Chembio samples were the most stable. CONCLUSIONS: Both collectors can be used for HBsAg detection in OF samples, but some modifications of commercial EIAs should be incorporated for Salivette device. OF samples were reliably stable and could be stored for up to 90 days at 2-8°C.

Seroprevalence of hepatitis B virus infection and associated factors among prison inmates in state of Mato Grosso do Sul, Brazil.

INTRODUCTION: This study aimed to estimate the prevalence of HBV infection and associated factors among prison inmates in Campo Grande, MS. METHODS: A total of 408 individuals were interviewed regarding sociodemographic characteristics, associated factors and HBV vaccination using a standardized questionnaire. Blood samples were collected from all participants and serological markers for HBV were detected by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis B core antigen (anti-HBc) positive samples were tested for HBV-DNA by polymerase chain reaction. RESULTS: The overall prevalence of HBV infection was 17.9% (95%CI: 14.4-22.0). The HBsAg carrier rate was 0.5%; 56 (13.7%) individuals had been infected and developed natural immunity and 15 (3.7%) were positive for anti-HBc only. Ninety eight (24%) prisoners had only anti-HBs, suggesting that they had low vaccine coverage. An occult HBV infection rate of 0% was verified among anti-HBc-positive individuals. Multivariate analysis of associated factors showed that age > 35 years-old, low schooling level and illicit drug use are significantly associated with HBV infection. CONCLUSIONS: Analysis of the data showed HBV infection prevalence similar or slightly lower than that reported in other of Brazilian prisons. Independent predictors of HBV infection in this population include older age, low schooling level and illicit drug use.

Seroprevalence of hepatitis B virus infection and associated factors among prison inmates in state of Mato Grosso do Sul, Brazil / Soroprevalência e fatores associados à infecção pelo vírus da hepatite B em população encarcerada no estado do Mato Grosso do Sul, Brasil

INTRODUCTION: This study aimed to estimate the prevalence of HBV infection and associated factors among prison inmates in Campo Grande, MS. METHODS: A total of 408 individuals were interviewed regarding sociodemographic characteristics, associated factors and HBV vaccination using a standardized questionnaire. Blood samples were collected from all participants and serological markers for HBV were detected by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis B core antigen (anti-HBc) positive samples were tested for HBV-DNA by polymerase chain reaction. RESULTS: The overall prevalence of HBV infection was 17.9 percent (95 percentCI: 14.4-22.0). The HBsAg carrier rate was 0.5 percent; 56 (13.7 percent) individuals had been infected and developed natural immunity and 15 (3.7 percent) were positive for anti-HBc only. Ninety eight (24 percent) prisoners had only anti-HBs, suggesting that they had low vaccine coverage. An occult HBV infection rate of 0 percent was verified among anti-HBc-positive individuals. Multivariate analysis of associated factors showed that age > 35 years-old, low schooling level and illicit drug use are significantly associated with HBV infection. CONCLUSIONS: Analysis of the data showed HBV infection prevalence similar or slightly lower than that reported in other of Brazilian prisons. Independent predictors of HBV infection in this population include older age, low schooling level and illicit drug use.

INTRODUÇÃO: O presente estudo teve como objetivo investigar a prevalência da infecção pelo HBV e os fatores associados a esta infecção em população encarcerada de Campo Grande, MS. MÉTODOS: Quatrocentos e oito encarcerados, provenientes das populações encarceradas do Instituto Penal de Campo Grande, Presídio de Segurança Máxima e Presídio Feminino Irmã Irma Zorzi, foram entrevistados sobre dados sociodemográficos e fatores associados à infecção pelo HBV. A seguir foram coletadas amostras sanguíneas para detecção dos marcadores HBsAg, anti-HBs e anti-HBc total por ensaio imunoenzimático. O HBV-DNA foi detectado pela reação em cadeia da polimerase nas amostras HBsAg e anti-HBc reagentes. RESULTADOS: A prevalência global para infecção pelo HBV foi de 17,9 por cento (IC 95 por cento: 14,4-22,0), 13,7 por cento (56/408) para o anti-HBc total associado ao anti-HBs e em 15 (3,7 por cento) indivíduos foi detectada a presença do anti-HBc isolado. HBsAg foi encontrado em 0,5 por cento (2/408) dos indivíduos estudados, evidenciando uma baixa prevalência de casos crônicos. Em 24 por cento (98/408) dos indivíduos, verificou-se positividade isolada ao marcador anti-HBs, sugerindo baixa cobertura vacinal ao HBV. Após análise multivariada, ter idade maior que 35 anos, baixo nível de escolaridade e uso de droga ilícita permaneceram associados significativamente à infecção pelo HBV. CONCLUSÕES: A prevalência da infecção pelo HBV encontrada foi similar às reportadas em outros estudos conduzidos em populações encarceradas do Brasil. Os fatores de risco associados a esta infecção foram aumento da idade, baixo nível de escolaridade e uso de droga ilícita.