Hepatitis A in Latin America: The current scenario.

This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.

Association between hepatitis A seropositivity and bone mineral density in adolescents and adults: a cross-sectional study using NHANES data.

BACKGROUND: Osteoporosis, characterized by decreased bone density and increased fracture risk, imposes significant physical, psychosocial, and financial burdens. Early detection and prevention are crucial for managing osteoporosis and reducing the risk of fractures. OBJECTIVES: To investigate the relationship between Hepatitis A seropositivity and bone mineral density (BMD) in adolescents and adults and to explore the potential link between Hepatitis A infection and osteoporosis risk. DESIGN AND SETTING: This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018 to evaluate the association between hepatitis A seropositivity and BMD in 15,693 participants. METHODS: Multivariable regression analysis was used to calculate the mean BMD and standard error for adolescents and adults, followed by an independent z-test to determine whether there was a significant difference between the seropositive and seronegative groups. RESULTS: Hepatitis A seropositive adolescents and adults had lower BMD than their seronegative counterparts, with significant differences in lumber spine (mean difference = -0.03 g/cm2, P < 0.01 for both age groups) and pelvis BMDs (mean difference = -0.02 g/cm2, P < 0.01 for the adult age groups), after adjusting for various covariates. CONCLUSIONS: This study confirmed that both adolescent and adult individuals seropositive for Hepatitis A antibodies had reduced BMD among both adolescents and adults, especially in the adult group. This finding suggests a possible link between Hepatitis A infection and risk of osteoporosis.

Antibody persistence 7 years after hepatitis-A vaccine in children with human immunodeficiency virus infection.

BACKGROUND: HIV-infected children have a higher risk of presenting infections, including the hepatitis A virus (HAV). The inactivated HAV vaccine is immunogenic in immunocompetent hosts; however, there are insufficient studies on the duration of seroprotection in HIV-infected children. METHODS: An analytical cohort study was conducted. HIV-1-infected children who received the inactivated HAV vaccine (2 doses) were included. Blood samples were taken for antibody measurement, the first one 28 days after the second dose and another 7 years after the vaccination schedule. Information on viral load, immunological category, weight, height, and response to antiretroviral treatment from diagnosis to the last assessment was obtained. RESULTS: 19 patients were included, with a mean age of 12.6 years (SD ± 2.29). 58% were male. 80% of the patients presented protective immunoglobulin G antibodies against HAV 7-year post-vaccination. The antibody concentration was found to be between 13 and 80 mIU/mL (median of 80 mIU/mL). 52% showed some degree of immunosuppression. There was no statistically significant relationship between the presence of seroprotection and viral load, treatment failure, immunological category, and malnutrition. Twelve patients presented with antiretroviral treatment failure, and in 33% of them, the antibodies did not offer satisfactory seroprotection. CONCLUSION: 7-year post-vaccination, 80% of HIV-infected children maintain seroprotection titers against HAV.

INTRODUCCIÓN: Los niños infectados por el virus de la inmunodeficiencia humana (VIH) tienen mayor riesgo de presentar infecciones, incluyendo hepatitis por virus A (VHA). La vacuna inactivada contra el VHA es inmunógena en el huésped inmunocompetente. No hay estudios suficientes sobre el tiempo de seroprotección en niños infectados por el VIH. MÉTODO: Estudio de cohorte, analítico. Se incluyeron niños con infección por VIH-1 que recibieron la vacuna inactivada contra el VHA (dos dosis). Se les tomaron muestras sanguíneas para medición de anticuerpos, una 28 días después de la segunda dosis y otra 7 años después del esquema de vacunación. Se obtuvo información de carga viral, categoría inmunológica, peso y talla, y respuesta al tratamiento antirretroviral desde el diagnóstico hasta la última valoración. RESULTADOS: Se incluyeron 19 pacientes con una edad media de 12.6 años (± 2.29). El 58% fueron del sexo masculino. El 80% de los pacientes presentaron anticuerpos immunoglobulin G (IgG) contra el VHA protectores a los 7 años de la vacunación. La concentración de anticuerpos se encontró entre 13 y 80 mUI/ml (mediana: 80 mUI/ml). El 52% mostraron algún grado de inmunosupresión. No existe relación estadísticamente significativa entre la presencia de seroprotección y la carga viral, la falla al tratamiento, la categoría inmunológica ni la desnutrición. Doce pacientes presentaron falla al tratamiento antirretroviral; en el 33% de ellos los anticuerpos no ofrecían seroprotección satisfactoria. CONCLUSIONES: A 7 años posvacunación, el 80% de los niños con VIH mantienen títulos de seroprotección frente al VHA.

Rising trend of symptomatic infections due to Hepatitis A virus infection in adolescent and adult age group: An observational study from a tertiary care liver institute in India.

BACKGROUND: Hepatitis A Virus (HAV) is the most common cause of Acute Viral Hepatitis (AVH) in children. It causes self-limiting illness and rarely acute liver failure. The shifting pattern in HAV endemicity is rendering adolescents and adults vulnerable to infection. METHODS: In this retrospective study, samples received from 14,807 patients with acute onset icteric illness from January 2014-December 2022 were analyzed. HAV infection was detected by anti-HAV IgM positivity. The cases were divided into 3 age groups, pediatric, adolescents and adults, and clinical presentations were compared. RESULTS: Overall, 7.72%(1144) were positive for anti-HAV IgM. Of these, 60%(690) were finally included in the study. The positive cases were divided into adults, ≥18 years (44%, 304); pediatric, <12 years (31%, 212) and adolescents (25%,174) age groups. Overall males were predominant [72.4%(500)], with a median age of 16 (IQR:9-21) years. Cases were characterised into AVH (68.1%, 470/690), Acute Liver Failure (ALF) (31.4%, 217/690) and Acute-on-Chronic Liver Failure (0.43%, 3/690). AVH in the pediatric age group was 69%(146/212), adolescents was 67%(117/174), and adults was 68%(207/304). ALF cases among the 3 groups were 30%(65/212), 33%(57/174), and 31%(95/304) respectively. Overall mortality was seen in 6.52%(45/690), maximum in adolescents with ALF presentation [10.3%(18/174)]. On molecular characterization of infection, viremia was seen in 28.9%(200/690) and all the isolates were Genotype IIIA. CONCLUSIONS: The number of adults experiencing symptomatic HAV infection was seen to increase over the years in the present study. Infection in adolescents was associated with higher mortality and ALF as the clinical presentation.

Factors associated with hepatitis A susceptibility among men who have sex with men using HIV pre-exposure prophylaxis in Northeastern Brazil: A cross-sectional study.

Hepatitis A virus (HAV) infection has disproportionately affected more men who have sex with men (MSM), occurring in outbreaks, despite being vaccine-preventable. We determined the prevalence and factors associated with HAV susceptibility among cisgender MSM on HIV pre-exposure prophylaxis (PrEP) in Northeastern Brazil. From September 30, 2021 to June 19, 2023, 282 cisgender MSM receiving HIV PrEP were enrolled into this cross-sectional study. Sociodemographic and clinical information were collected. Blood samples were collected for screening of sexually transmitted infections (STIs) and serum samples were tested for IgM and total anti-HAV antibodies. Non-reactive results for total anti-HAV antibodies were found in 106 of 282 (37.6%) participants. Factors associated with HAV susceptibility included age <30 years (prevalence ratio [PR]: 2.02; 95% confidence interval [95% CI]: 1.61-2.53), having health insurance (PR: 1.39; 95% CI: 1.19-1.64), sex only with cisgender men (PR: 1.52; 95% CI: 1.23-1.89), non-steady partner (PR: 1.20; 95% CI: 1.01-1.43) and no lifetime history of STIs (PR: 1.25; 95% CI: 1.03-1.53). Identifying clinical correlates of HAV susceptibility in key populations is a fundamental step towards development of public policy focused on prevention, especially following the recent hepatitis A outbreak in Brazil.

Prevalence of hepatitis A virus among migrant workers in Qatar: A national study.

BACKGROUND: Hepatitis A virus (HAV) is the predominant cause of acute viral hepatitis worldwide; however, data on HAV antibody prevalence (seroprevalence) among migrant populations are limited. This study aimed to investigate HAV seroprevalence among Qatar's migrant craft and manual workers (CMWs), constituting approximately 60% of the country's population. METHODS: HAV antibody testing was conducted on stored serum specimens obtained from CMWs during a nationwide severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) population-based cross-sectional survey between July 26 and September 9, 2020. Associations with HAV infection were investigated through regression analyses. RESULTS: Of the 2,607 specimens with HAV antibody test results, 2,393 were positive, and 214 were negative. The estimated HAV seroprevalence among CMWs was 92.0% (95% CI: 90.9-93.1%). HAV seroprevalence was generally high but exhibited some variation, ranging from 70.9% (95% CI: 62.4-78.2%) among Sri Lankans to 99.8% (95% CI: 98.2-99.9%) among Pakistanis. The multivariable regression analysis identified age, nationality, and educational attainment as statistically significant factors associated with HAV infection. Relative to CMWs aged ≤29 years, the adjusted relative risk (ARR) was 1.06 (95% CI: 1.03-1.10) in CMWs aged 30-39 years and reached 1.15 (95% CI: 1.10-1.19) in those aged ≥50 years. In comparison to Indians, the ARR was lower among Sri Lankans, assessed at 0.81 (95% CI: 0.72-0.91), but higher among Nepalese at 1.07 (95% CI: 1.04-1.11), Bangladeshis at 1.10 (95% CI: 1.07-1.13), Pakistanis at 1.12 (95% CI: 1.09-1.15), and Egyptians at 1.15 (95% CI: 1.08-1.23). No evidence for differences was found by geographic location or occupation. CONCLUSIONS: HAV seroprevalence among Qatar's CMW population is very high, with over nine out of every ten individuals having been exposed to this infection, likely during childhood.

Hepatitis A and E among immigrants and refugees in Central Brazil

ABSTRACT OBJECTIVE To estimate the prevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) among immigrants and refugees in Goiás, Central Brazil. METHODS Overall, 355 individuals were interviewed, and blood samples were tested for anti-HAV and anti-HEV IgG. Anti-HEV-positive samples were similarly tested for HEV RNA. RESULTS All participants were from Latin American countries, most of whom, young adult males. The overall anti-HAV IgG prevalence was 87.4% (95%CI: 83.5-90.4), of whom 94.9%, 75.6%, and 60% were from Haiti, Venezuela, and other Latin American countries, respectively (p < 0.001). Age above 19 years and more than 36 months residing in Brazil were associated with a higher prevalence of previous HAV and HEV infection, respectively. Of the children eligible for HAV vaccination according to the National Immunization Program, only eight (44%) had been vaccinated. The overall anti-HEV IgG prevalence was 6.5% (95%CI: 4.4-9.5). All anti-HEV IgG-positive individuals were Haitians, including a child born in Brazil. HEV RNA was detected in two of the anti-HEV IgG-positive samples. CONCLUSION The survey detected a high prevalence of anti-HAV and anti-HEV IgG among immigrants and refugees, and active HEV infection among some Haitian participants. Prevention measures are urgently required to interrupt enteric virus transmission in this emergent and vulnerable population.

Initial evaluation of universal immunization with a single dose against hepatitis A virus in Central Brazil

ABSTRACT Vaccination against the hepatitis A virus (HAV) administered in two doses has been used effectively in universal child immunization programs in several countries. A single-dose vaccination was adopted in some low-income countries in an attempt to reduce costs without losing effectiveness. In 2014, single-dose universal vaccination was introduced in Brazil for children aged two years. Since such strategy is still not universally accepted, its efficacy should be compared to the two-dose strategy. To assess the humoral response after the single-dose HAV vaccination schedule, a cross-sectional study was conducted in Primavera do Leste, in Mato Grosso state, Central Brazil, including 265 children vaccinated through the National Immunization Program. Blood was collected by using a digital puncture and further applied to filter paper cards. Anti-HAV was detected in 218 out of 265 dried blood spots (DBS). Blood venous samples were collected from 34 out of 47 children who were not anti-HAV positive in DBS samples. Eighteen of them tested positive for anti-HAV, giving a final score of 93.6% (236/252) of seropositivity. In conclusion, this study demonstrated a high rate of anti-HAV positivity in the short term after single-dose hepatitis A vaccination in the population investigated. Moreover, the DBS was shown to be a reliable tool for detecting anti-HAV antibodies.

SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANÁ RIVER BASIN, BRAZIL

Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated.

Hepatitis A seroprevalence in public school children in Campos dos Goytacazes, Rio de Janeiro State, Brazil, prior to the introduction of the hepatitis A universal childhood vaccination / Soroprevalência da hepatite A em crianças de escolas públicas em Campos dos Goytacazes, Rio de Janeiro, Brasil, antes da introdução da vacinação infantil universal / Seroprevalencia de la hepatitis A en niños de escuelas públicas en Campos dos Goytacazes, Río de Janeiro, Brasil, antes de la introducción de la vacunación infantil universal

Abstract: This cross-sectional study was carried out between August 2011 and July 2012 in the city of Campos dos Goytacazes in Rio de Janeiro State, Brazil. Dried blood spot samples were collected on filter paper from 919 individuals between the ages of 1 and 19 and were tested for antibodies against the hepatitis A virus (anti-HAV). The total prevalence was 20.7%, while 94.7% of children under the age of 5 were found to be susceptible to HAV infection. The prevalence of anti-HAV increased with age, reaching 33.3% among individuals aged between 15 and 19, thereby indicating that this municipality has a low level of endemicity for hepatitis A. Age, non-white skin color, accustomed to swimming in the river and more than five people living at home were the factors that were associated with an increase in the chance of a positive anti-HAV result. Mother's education level (secondary or tertiary) was considered a protective factor for HAV infection. The data obtained showed that a large proportion of the children from Campos dos Goytacazes were at risk of HAV infection, which should be minimized with the introduction of the vaccination program against hepatitis A that was launched in the municipality in 2011.

Resumo: Estudo do corte transversal, realizado entre agosto de 2011 e julho de 2012 em Campos dos Goytacazes, Rio de Janeiro, Brasil. Amostras de sangue capilar em papel de filtro foram coletadas de 919 indivíduos com idade entre 1 e 19 anos e testadas para anticorpos para o vírus da hepatite A (anti-HAV). A prevalência total foi de 20,7% e 94,7% das crianças abaixo de 5 anos foi suscetível a infecção pelo HAV. A prevalência de anti-HAV aumentou com a idade, alcançando 33,3% entre indivíduos com 15 a 19 anos, caracterizando este município com um nível baixo de endemicidade para hepatite A. Idade, cor da pele não-branca, hábito de nadar no rio e número de moradores na residência acima de 5 foram associados com o aumento de chance de ser positivo para anti-HAV. O nível educacional materno (médio ou superior) foi considerado como fator de proteção para a infecção pelo HAV. Os dados obtidos mostraram que uma grande parte das crianças de Campos dos Goytacazes estava sob risco de infecção pelo HAV, o que deve ser minimizado com o programa de vacinação contra hepatite A implantado em 2011 no município.

Resumen: Estudio de corte transversal, realizado entre agosto de 2011 y julio de 2012 en Campos dos Goytacazes, Río de Janeiro, Brasil. Se recogieron muestras de sangre capilar en papel de filtro de 919 individuos con una edad entre 1 y 19 años y testadas para anticuerpos del virus de la hepatitis A (anti-HAV). La prevalencia total fue de un 20,7% y un 94,7% de los niños por debajo de los 5 años fue susceptible a la infección por el HAV. La prevalencia de anti-HAV aumentó con la edad, alcanzando un 33,3% entre individuos con 15 a 19 años, caracterizando este municipio con un nivel bajo de endemicidad para la hepatitis A. Edad, color de piel no-blanca, hábito de nadar en el río y un número de ocupantes en la residencia de más de 5 se asociaron con el aumento de oportunidad de ser positivo para anti-HAV. El nivel educacional materno (medio o superior) se consideró como un factor de protección para la infección por el HAV. Los datos obtenidos mostraron que una gran parte de los niños de Campos dos Goytacazes estaba bajo riesgo de infección por el HAV, lo que debe ser minimizado con el programa de vacunación contra la hepatitis A implantado en 2011 en el municipio.

Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections

An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

An immunoenzymatic assay for the diagnosis of hepatitis A utilising immunoglobulin Y

The detection of anti-hepatitis A virus (HAV) antibody levels by diagnostic kits in the convalescent period of disease generally use immunoglobulin G (IgG), which is expensive. An alternative to IgG is immunoglobulin Y (IgY), an immunoglobulin antibody encountered in birds and reptiles. The aim of this study was to develop a competitive immunoenzymatic assay to measure total anti-HAV antibody levels using anti-HAV IgY as the capture and conjugated immunoglobulins. For this purpose, anti-HAV IgY was conjugated to horseradish peroxidase (HRP) and the optimal dilution of HRP-conjugated antibodies was evaluated to establish the competitive immuneenzymatic assay. The results obtained from our "in-house" assay were plotted on a receiver operator curve, which showed a sensitivity of 95% and a specificity of 98.8%, demonstrating that a competitive anti-HAV IgY immunoenzymatic assay developed "in house" could be used as an alternative to commercial assays that utilise IgG.

Declining prevalence of hepatitis A virus antibodies among children from low socioeconomic groups reinforces the need for the implementation of hepatitis A vaccination in Brazil

Age-related seroprevalence studies that have been conducted in Brazil have indicated a transition from a high to a medium endemicity of hepatitis A virus (HAV) infection in the population. However, most of these studies have focused on urban populations that experience lower incidence rates of HAV infection. In the current study, the prevalence of anti-HAV antibodies was investigated in children with a low socioeconomic status (SES) that live on the periphery of three capital cities in Brazil. A total of 1,162 dried blood spot samples were collected from individuals whose ages ranged from one-18 years and tested for anti-HAV antibodies. A large number of children under five years old (74.1-90%) were identified to be susceptible to HAV infection. The anti-HAV antibody prevalence reached ≥ 50% among those that were 10-14 years of age or older. The anti-HAV prevalence rates observed were characteristics of regions with intermediate level of hepatitis A endemicity. These data indicated that a large proportion of children with a low SES that live at the periphery of urban cities might be at risk of contracting an HAV infection. The hepatitis A vaccine that is currently offered in Brazil is only available for high-risk groups or at private clinics and is unaffordable for individuals with a lower SES. The results from this study suggest that the hepatitis A vaccine should be included in the Brazilian National Program for Immunisation.

Epidemiological and serological aspects of hepatitis A among children and teenagers in the city of Santos: a cross-sectional study / Aspectos epidemiológicos e sorológicos da hepatite A em crianças e adolescentes na cidade de Santos: estudo transversal

CONTEXT AND OBJECTIVE: Viral hepatitis A is still a concern at public health level in Brazil and around the world, due both to the number of affected subjects and the possibility of complications in the acute forms. The Brazilian Ministry of Health estimates that at least 70% of this country's population has already had contact with the hepatitis A virus (HAV). The aim here was to discover the prevalence of serological markers for the hepatitis A virus among children and teenagers at daycare facilities, kindergartens and elementary schools in the city of Santos. DESIGN AND SETTING: Cross-sectional study in kindergartens and elementary schools within the municipal education network in several regions of the city of Santos. METHOD: Students' family members were surveyed using a questionnaire and 4,680 finger-prick blood samples were taken and assayed by means of the ELISA technique. RESULTS: The general prevalence of anti-HAV IgG was 9.72% and, of these cases, 74.6% were reactive to anti-HAV IgM. There was higher prevalence of anti-HAV IgG among older children, females, children who played in streams, those whose homes were not connected to the sewage system, those whose parents had low education levels, those with low household income and those who did not live along the seashore. The prevalence of anti-HAV IgM peaked in the early years and subsequently fell, and it was lower on the hills and in the Northwestern Zone. CONCLUSION: The general prevalence of serological markers for hepatitis A was low in Santos.

CONTEXTO E OBJETIVO: A hepatite viral A continua sendo uma preocupação em nível de saúde pública no Brasil e no mundo, tanto pelo número de indivíduos atingidos, como pela possibilidade de complicação das formas agudas. O Ministério da Saúde estima que pelo menos 70% da população do Brasil já tiveram contato com o vírus da hepatite A. O objetivo foi conhecer a prevalência de marcadores sorológicos do vírus da hepatite A em crianças e adolescentes de creches e escolas de ensino infantil e fundamental na cidade de Santos. TIPO DE ESTUDO E LOCAL: Estudo transversal em pré-escolas e de ensino fundamental da rede municipal em diversas regiões da cidade de Santos. MÉTODO: Foi aplicado um questionário aos familiares dos estudantes e coletadas 4.680 amostras de sangue através de punção capilar para realização da sorologia pela técnica ELISA. RESULTADOS: A prevalência geral do anti-HVA IgG foi de 9,72% e, desses, 74,6% foram anti-HVA IgM reagentes. A prevalência de anti-HVA IgG foi maior entre as crianças mais velhas, meninas, aquelas que brincavam em córregos, sem rede de coleta de esgoto em sua moradia, de pais com baixa instrução, de baixa renda familiar e aquelas que não eram moradoras da orla. A prevalência de anti-HVA IgM teve pico nos primeiros anos e posterior queda e, no morro e Zona Noroeste, foi mais baixa. CONCLUSÃO: A prevalência geral dos marcadores sorológicos para hepatite A foi baixa em Santos.

Mudança na suscetibilidade à hepatite A em crianças e adolescentes na última década / Shifting susceptibility to hepatitis A among children and adolescents over the past decade

OBJETIVOS: Estimar a prevalência de anticorpos contra hepatite A (anti-VHA) em grupo de crianças e adolescentes de laboratório público e privado em Porto Alegre e comparar com estudo realizado na década anterior. MÉTODOS: Entre 2007 e 2008 foi realizado estudo transversal onde foram incluídas, consecutivamente, 465 amostras de soros de crianças e adolescentes entre 1 e 19 anos de idade para determinar a prevalência de anticorpos anti-VHA total. As amostras foram fornecidas por laboratório público (grupo 1), que atende somente Sistema Único de Saúde, e por laboratório privado (grupo 2), representando os estratos socioeconômicos mais baixo e mais alto, respectivamente. O teste foi realizado em único laboratório (eletroquimioluminescência, Roche Diagnostics). Resultados > 20 UI/L foram considerados positivos. RESULTADOS: A soroprevalência de anti-VHA no grupo 1 foi de 37,6 por cento e o percentual de positividade aumentou conforme a idade, variando de 19,4 por cento entre 1-4 anos a 54,1 por cento entre 15-19 anos. No grupo 2, a frequência de anti-VHA foi de 46,1 por cento e foi inversamente relacionada à idade, caindo de cerca de 50,0 por cento nas faixas etárias menores para 29,1 por cento aos 15-19 anos. Houve diminuição significativa na prevalência do anti-VHA nas crianças de 5-9 anos do grupo 1 (p = 0,03), quando comparadas com estudo realizado na década de 1990. CONCLUSÕES: Os resultados sugerem queda na endemicidade da hepatite A em Porto Alegre na última década e indicam maior suscetibilidade à doença em crianças e adolescentes, principalmente no estrato socioeconômico mais baixo.

OBJECTIVES: To estimate the prevalence of anti-hepatitis A virus (anti-HAV) antibodies in serum samples from children and adolescents obtained at two clinical pathology laboratories in the city of Porto Alegre, south of Brazil, and to compare findings to those of a study carried out in the 1990s. METHODS: In this cross-sectional study conducted between 2007 and 2008, 465 serum samples obtained from subjects aged 1-19 years were consecutively tested to determine the prevalence of total anti-HAV antibodies. Samples were provided by a public laboratory (group 1) that serves the Unified Health System exclusively, meant to represent the lowest socioeconomic strata, and by a private laboratory (group 2), meant to represent the higher socioeconomic classes. Tests were performed at a single laboratory using commercially available electrochemiluminescence kits. Antibody levels > 20 UI/L were considered positive. RESULTS: The seroprevalence of anti-HAV in Group 1 was 37.6 percent. The percentage of anti-HAV reactivity increased from 19.4 percent in the 1-to-4 group to 54.1 percent in the 15-to-19 group. In Group 2, overall anti-HAV positivity was 46.1 percent and was inversely correlated with age, declining from roughly 50 percent in the youngest groups to 29.1 percent in the 15-to-19 group. Comparison of sample findings to those reported in a 1990s study showed a significant reduction in anti-HAV prevalence among 5-to-9-year-olds in group 1 (p = 0.03). CONCLUSIONS: The results suggest that the endemicity of hepatitis A in Porto Alegre has been declining over the past decade, and that children and adolescents, particularly those in the lowest socioeconomic strata, are more susceptible to the disease.

Hepatite A: soroprevalência e fatores associados em escolares de São Luís (MA), Brasil / Hepatitis A: seroprevalence and associated factors among schoolchildren of São Luís (MA), Brazil

OBJETIVOS: Estimar a prevalência de anticorpos contra o vírus da hepatite A (antiVHA-IgG) em escolares de 7 a 14 anos de escolas públicas e privadas e identificar fatores demográficos, socioeconômicos e sanitários associados à prevalência de antiVHA-IgG. MÉTODOS: Estudo soroepidemiológico para detecção de antiVHA-IgG, de abril de 2002 a abril de 2004, em 462 escolares de São Luís, com idades compreendidas entre 7 e 14 anos, do ensino fundamental. Participaram 30 escolas aleatoriamente selecionadas, com probabilidade proporcional ao número de alunos matriculados, sendo 23 públicas e 7 privadas. Os dados foram obtidos por meio de questionário estruturado. Para se identificar variáveis independentemente associadas à prevalência do antiVHA-IgG, foi realizada análise de regressão de Poisson múltipla, sendo estimadas as RPs ajustadas e respectivos intervalos de confiança de 95 por cento. Somente permaneceram no modelo final aquelas variáveis associadas com a prevalência da hepatite A com p < 0,10. Foi adotado o nível de significância de 0,05 (α = 0,05). RESULTADOS: A prevalência de antiVHA-IgG foi de 64 por cento, sendo de 71,5 por cento nas escolas públicas e de 36,5 por cento nas privadas. Após análise multivariável, idade de 11 a 14 anos, mais de uma pessoa por dormitório e menos de dois banheiros por domicílio foi associada a maiores prevalências de antiVHA-IgG. Maior escolaridade dos pais esteve associada à menor prevalência de antiVHA-IgG. CONCLUSÕES: A hepatite A é endêmica nos escolares de São Luís, com taxa de prevalência semelhante àquela encontrada em outras regiões do país com condições socioeconômicas e sanitárias similares. Fatores historicamente associados à maior prevalência da hepatite A foram também identificados nesta população.

OBJECTIVES: To estimate the prevalence of antibodies to hepatitis A virus (antiVHA-IgG) in children aged 7-14 years from public and private schools, and to identify demographic, socioeconomic and sanitation factors associated with the prevalence of antiVHA-IgG. METHODS: Seroepidemiological study for the detection of IgG antiVHA. It was conducted from April 2002 to April 2004 with 462 elementary school students from São Luis, ranging from 7 to 14-years of age. Thirty schools randomly selected took part in the study, with a probability proportional to the number of students enrolled; 23 schools were public and 7 were private. Data was obtained through a structured questionnaire. In order to identify the variables independently associated with IgG antiVHA, the Poisson multiple regression analysis was performed, estimating the adjusted PRs and their 95 percent confidence intervals. The variables associated with the prevalence of hepatitis A with p < 0 were the only ones that remained in the final model. The level of significance of 0.05 (α = 0.05) was adopted. RESULTS: The prevalence of antiVHA-IgG was 64 percent, 71.5 percent in public and 36.5 percent in private schools. After multivariate analysis, age 11 to 14 years, more than one person per bedroom, and less than two bathrooms per household were associated with a higher prevalence of antiVHA-IgG. Higher parental education was associated with lower prevalence of antiVHA-IgG. CONCLUSIONS: Hepatitis A is endemic among schoolchildren in São Luís. The prevalence rate was similar to those found in other regions of the country with similar socio-economic and health conditions. Factors historically associated with a higher prevalence of hepatitis A were also identified in this population.

Soroprevalência de hepatite A em crianças e adolescentes / Seroprevalence of hepatitis A in children and adolescents

OBJETIVOS: Avaliar a soroprevalência de hepatite A (VHA) em crianças e adolescentes com idade entre 1 e 14 anos, e identificar fatores associados à infecção prévia. MÉTODO: Estudo epidemiológico transversal, realizado entre fevereiro e agosto de 2006, em Curitiba, Paraná, Brasil, e em sua região metropolitana. A análise laboratorial constituiu-se de pesquisa qualitativa de anticorpos totais para o VHA em amostra de sangue total. RESULTADOS: No estudo, 901 crianças e adolescentes foram incluídos. A distribuição por faixa etária foi: 237 (26,3 por cento) entre 1 e 4 anos; 313 (34,7 por cento) entre 5 e 9 anos; e 351 (39 por cento) entre 10 e 14 anos. A taxa de soroprevalência geral encontrada foi de 19,8 por cento, e por grupo etário foi de 3, 21,1 e 29,9 por cento (p < 0,01), respectivamente. Na análise multivariada, demonstrou-se que os fatores que, em conjunto, mantiveram associação positiva com as prevalências de anticorpos contra o VHA na população estudada foram: faixa etária de 5 a 9 e 10 a 14 anos, morar em casas com um ou mais habitantes por cômodo, frequentar refeitório comunitário e ter baixa renda per capita. CONCLUSÕES: Os resultados demonstraram uma baixa prevalência de anticorpos contra o VHA, o que justifica o uso de medidas profiláticas, que incluem a vacinação precoce.

OBJECTIVES: To determine the seroprevalence of hepatitis A (HAV) in children and adolescents aged 1 to 14 years, and to identify factors associated with a history of infection. METHOD: This was a cross-sectional epidemiological study, conducted form February to August 2006 in the city of Curitiba, Paraná, Brazil, and the surrounding municipalities (Greater Curitiba). Laboratory analysis comprised qualitative assay for total HAV antibodies in whole blood samples. RESULTS: A total of 901 children and adolescents were recruited for the study. Age distribution was as follows: 1 to 4 years, n = 237 (26.3 percent); 5 to 9 years, n = 313 (34.7 percent); and 10 to 14 years, n = 351 (39 percent). The global rate of seroprevalence was 19.8 percent, and seroprevalence rates by age group were 3 percent, 21.1 percent and 29.9 percent respectively (p < 0.01). Multivariate analysis demonstrated that the following factors, in combination, had a positive association with the prevalence rate of antibodies against HAV in the study population: age groups 5 to 9 and 10 to 14 years, living in a household with more than one inhabitant per room, shared eating area and low per capita income. CONCLUSIONS: The results show a low prevalence of antibodies against HAV, which justifies the use of prophylactic measures, including early vaccination.

Avaliação da utilização de ensaio imunocromatográfico para o diagnóstico e estudo de prevalência da hepatite A / Evaluation of an immunochromatographic assay for diagnosis and prevalence study of hepatitis A

O diagnóstico da infecção pelo vírus da hepatite A (HAV) através de testes de alta sensibilidade e especificidade pode levar um diagnóstico mais precoce e mais preciso,melhorando o prognóstico da doença. Deve também ser mencionado que um diagnóstico mais preciso pode tornar estudos epidemiológicos mais confiáveis e servir de base para a produção de programas de controle e erradicação mais efetivos. O objetivo deste estudo foi avaliar a utilização de um teste imunocromatográfico em surtos e estudos epidemiológicos de prevalência, triagem de candidatos para programas de vacinação e detecção de resposta imunológica pós-vacinação. Para este fim, 342 amostras provenientes de quatro grupos diferentes foram analisadas: (I) amostras de doadores de sangue (n= 96), (II) amostras de indivíduos vacinados contra a hepatite A (n= 46), amostras de surtos de hepatite A (III) (n=103) e (IV) amostras de casos esporádicos de hepatite A (n= 97). Estas amostras foram submetidas ao teste rápido SD BIOLINE HAV IgG/IgM e todos os resultados do teste rápido foram comparados com os resultados do ensaio imunoenzimático para HAV (EIA), que é o padrão ouro para detectar anticorpos contra o HAV...

The diagnosis of infection by the hepatitis A virus (HAV) through high sensitivity andspecificity tests can lead an earlier and more accurate diagnosis, improving the prognosis ofthe disease. It should also be mentioned that a more precise diagnosis can become morereliable epidemiological studies and as a basis for the production of more effective controland eradication programs. The aim of this study was to evaluate an immunochromatographictest in outbreaks and epidemiological studies of prevalence, screening candidates forvaccination and post-vaccination surveillance programs. For this purpose, 342 samples frompatients of four different groups were analyzed: (I) samples from blood donors (n=96), (II)samples from individuals vaccinated for hepatitis A (n=46), (III) samples from hepatitis Aoutbreaks (n=103) and (IV) samples from sporadic cases of hepatitis A (n=97). These sampleswere submitted to the rapid test SD BIOLINE HAV IgG/IgM and all results of the rapid testwere compared to the results of HAV enzyme immunoassay (EIA) that is the gold standard todetect antibodies against HAV. The results obtained for the group I showed that, 33.3%(32/96) were positive for anti-HAV IgG using the rapid test and 67.7% (65/96) were positivefor IgG anti-HAV by EIA. At group II, 71.7% (33/46) of the samples were positive for antiHAVIgG by EIA and none of them (0/33) was reactive by rapid test. Groups III and IV weretested for the presence of anti-HAV IgG and anti-HAV IgM antibodies...

Prevalence of hepatitis A virus infection: the paradoxical example of isolated communities in the western Brazilian Amazon region / Prevalência da infecção pelo vírus da hepatite A: o exemplo paradoxal de comunidades isoladas na região Amazônica Ocidental Brasileira

This study evaluated the prevalence of hepatitis A virus infection in the rural area of Lábrea, in the western Brazilian Amazon region. Communities and households were selected randomly. Serum samples were analyzed by means of the immunoenzymatic method for the presence of total antibodies against HAV. The study included 1,499 individuals. The prevalence of anti-HAV was 74.6 percent (95 percent CI 72.3-76.8). Univariate analysis showed associations with age (chi-square for linear trend = 496.003, p < 0.001), presence of outside toilet (p < 0.001), history of hepatitis (p < 0.001) and family history of hepatitis (p = 0.05). After adjusting for age, HAV infection also showed an association with the number of people in the family (p = 0.03). The overall prevalence rates were high, but not more than 60 percent of the children under the age of ten years had already been infected. Very high prevalence was detected only within older cohorts, thus paradoxically defining this as a region with intermediate endemicity, even under the conditions of poverty encountered.

Este estudo avaliou a prevalência de infecção pelo vírus da hepatite A na área rural de Lábrea, Amazônia Ocidental Brasileira. Comunidades e domicílios foram selecionados aleatoriamente. Amostras de soro foram analisadas pelo método imunoenzimático para os anticorpos totais contra o vírus da hepatite A. O estudo incluiu 1.499 indivíduos. A prevalência do anti-HAV foi 74,6 por cento (IC 95 por cento 72,3 a 76,8). Análise univariada mostrou associação com idade (qui-quadrado de tendência linear = 496,003, p<0,001), presença de sanitário fora do domicílio (p<0,001), passado de hepatite (p<0,001) e história familiar de hepatite (p=0,05). Depois de controlado por idade, a infecção pelo VHA mostrou também associação com o número de pessoas na família (p=0,03). A prevalência global mostra taxas elevadas, entretanto não mais do que 60 por cento dos menores de 10 anos, já são infectados, e prevalências elevadas são detectadas em coortes de mais idade, mostrando paradoxalmente uma definição de região de endemicidade intermediária, mesmo nas condições de pobreza encontradas.