Serological evidence of hepatitis E virus infection (HEV) has been observed in both humans

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The first report of a human autochthonous in Brazil contributes with new information for hepatitis E epidemiology in Latin America and to considerate further broadly epidemiological studies.

We investigated the seroprevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in subjects living in the community of Manguinhos, Rio de Janeiro, Brazil, and assisted Key words: hepatitis A virus -hepatitis E virus -seroprevalence -epidemiology -Rio de Janeiro -Brazil Viral hepatitis is a public health problem worldwide. Two of the agents that cause viral hepatitis are enterically transmitted: hepatitis A virus (HAV) and hepatitis E virus (HEV).In the last years, improvements in environmental sanitation and hygienic conditions, such as piped water and sewage system, have been responsible for a decrease in the endemicity level of hepatitis A in several developing countries. In Brazil, although hepatitis A is considered an endemic disease (Pannuti et al. 1985, Abuzwaida et al. 1987, Bensabath et al. 1987, Queiroz et al. 1995, data published in recent investigations carried out in the State of Rio de Janeiro revealed a shift in the hepatitis A epidemiological pattern. Improvements in life standards of some urban populations are responsible for a decrease in antibody prevalence among children and adolescents (Vitral et al. 1998a,b).HEV infection is quite common in some geographic areas like India, Africa and Southeast Asia, where it can represent the main cause of acute hepatitis (Arankalle et al. 1995 reported in these areas (Shakhgildyan et al. 1986, CDC 1987, Belyakov et al. 1990, Zuang 1992. On the other hand, epidemiological investigations in non-endemic areas show a low, but constant presence of anti-HEV antibodies (about 1.2%) in normal human populations (Balayan et al. 1996, Psichogiou et al. 1996, Irshad 1999.In 1986, the occurrence of outbreaks of HEV infection in the Americas was recognized in Mexico (Velazquez et al. 1990). More recently, two acute cases of hepatitis E were described in Argentina (Schlauder et al. 2000). In Brazil, outbreaks of hepatitis E have never been reported, although some authors found antibodies in some population groups (Focaccia et al. 1995, Parana et al. 1997, Souto & Fontes 1998, Trinta et al. 2001.Nowadays, hepatitis A can be prevented by active immunoprophylaxis and, for a better control of infection, it is necessary to investigate its current prevalence in different areas. On the other hand, further data are needed in order to evaluate the importance of HEV infection in our country. The aim of the present study was to evaluate the prevalence of HAV and HEV infections in an area where sanitary conditions were improved over the last few years. MATERIALS AND METHODSCalculation of sample size -The minimum sample size was estimated using the formula: n = Z² P Q / d², considering as n = estimated sample size; Z = reduced variable, which value is 1,96 when alpha = 0,05; P (estimated prevalence) = probability to achieve the studied phenomenon; Q (1-P) = complement of the estimated prevalence; d (desired precision) = margin of error.

BackgroundHepatitis E virus (HEV) has been described as an emerging pathogen in Brazil and seems to be widely disseminated among swine herds. An autochthonous human case of acute hepatitis E was recently reported. To obtain a better understanding of the phenotypic profiles of both human and swine HEV strains, a experimental study was conducted using the animal model, Macaca fascicularis.MethodsSix cynomolgus monkeys (Macaca fascicularis) were inoculated intravenously with swine HEV genotype 3 that was isolated from naturally and experimentally infected pigs in Brazil and the Netherlands. Two other monkeys were inoculated with HEV genotype 3 that was recovered from Brazilian and Argentinean patients with locally acquired acute and fulminant hepatitis E. The haematological, biochemical, and virological parameters of all animals were monitored for 67 days.ResultsSubclinical hepatitis was observed in all monkeys after inoculation with HEV genotype 3 that was recovered from the infected swine and human patients. HEV RNA was detected in the serum and/or faeces of 6 out of the 8 cynomolgus monkeys between 5 and 53 days after inoculation. The mild inflammation of liver tissues and elevations of discrete liver enzymes were observed. Seroconversions to anti-HEV IgM and/or IgG were detected in 7 animals. Reactivities to anti-HEV IgA were also detected in the salivary samples of 3 animals. Interestingly, all of the infected monkeys showed severe lymphopenia and a trend toward monocytosis, which coincided with elevations in alanine aminotransferase and antibody titres.ConclusionsThe ability of HEV to cross the species barrier was confirmed for both the swine (Brazilian and Dutch) and human (Argentinean) strains, thus reinforcing the zoonotic risk of hepatitis E in South America. Cynomolgus monkeys that were infected with HEV genotype 3 developed subclinical hepatitis that was associated with haematological changes. Haematological approaches should be considered in future studies of HEV infection.

ResumoEm 1995, foi identificada epidemia comunitária de hepatite B entre colonos agrícolas recentemente assentados em Cotriguaçu, noroeste de Mato Grosso. Houve campanha de vacinação nos municípios da região. Nos anos seguintes, manteve-se a estratégia de vacinar a população e os migrantes que continuaram chegando àquele município. Em 2001, foi realizado novo inquérito sorológico de marcadores da hepatites B com o objetivo de avaliar a magnitude do problema e o impacto das medidas tomadas previamente. A comunidade de Nova União foi escolhida por ser a área de maior atração de migrantes a partir do final da década de 90. Foram estudados 838 indivíduos, encontrando-se 40,0% já infectados pelo vírus da hepatite B (VHB), 2,1% de portadores do vírus e 40,8% protegidos por vacinação. A maioria dessa população era composta de migrantes vindos de Rondônia. Entre os portadores do VHB, 28,0% tinham marcadores de hepatite D. As variáveis associadas à infecção pelo VHB foram: atividade sexual; etilismo; contato com caso de hepatite; e ter vivido em garimpo. Esse padrão de moderada prevalência é diferente do observado em 1995, ocasião em que se evidenciou alta prevalência. Observou-se associação do VHB com aumento da idade e com início da atividade sexual. Como a migração para aquela área continua intensa, recomenda-se que a atual estratégia de vacinação continue. Especial atenção deve ser dedicada à progressiva entrada do vírus da hepatite Delta (VHD) na região.

, many cases of hepatitis A were notified in the county of Belford Roxo involving individuals aged 0 to 79 years. Serum samples were collected to evaluate the prevalence of anti-hepatitis A virus (HAV) antibodies, to detect HAV-RNA and to correlate with possible risk factors of HAV infection. Serum samples were screened by commercial IgM and total anti-HAV antibody ELISA and HAV-RNA was isolated and subsequently amplified by reverse transcription-polymerase chain reaction (RT-PCR) at VP1/2A region, and Key words: hepatitis A virus -molecular epidemiology -co-circulation of subgenotypes IA and IB Hepatitis A virus (HAV) is an RNA virus that is transmitted mainly by fecal oral route and is the only member of the genus Hepatovirus of the Picornaviridae family (Melnick 1982(Melnick , 1992. Studies on nucleic acid heterogeneity of HAV strains, in VP1/2A junction, characterize and group isolates in six different genotypes (I-VI) and six sub-genotypes (IA, IB, IIA, IIB, IIIA, and IIIB) (Robertson et al. 1992. Genotypes are distinguished by 15-25% sequence diversity, whereas sub-genotypes in each genotype differ in about 7.5% of base positions (Robertson et al. 1992). Comparison among nucleotide sequences allows genetically relating different strains during an outbreak and providing new insights into the molecular epidemiology of HAV.HAV is the main cause for acute viral hepatitis which represents a significant public health problem worldwide. However, a progressive decline in hepatitis A mortality rate could be seen in all Brazilian regions, being observed a rate of 0.2/100,000 inhabitants in 1980 to the rate of 0.02/100,000 inhabitants in (Vitral et al. 1998. The incidence of hepatitis A in Brazil has markedly decreased as showed by Vitral et al. (1998) 98.1 to 7.8% among children under the age of five in two different populations of low socioeconomic status in Rio de Janeiro, a city located in the Southeastern region (Vitral et al. 1998). This phenomenon can probably be attributed to improvements in sanitary conditions. If this hypothesis is true, then the transmission route of HAV in Brazil may have changed within time. Studying changes in HAV transmission routes in Brazil may therefore elucidate the influence of sanitation on transmission routes. Molecular epidemiological approaches may also be useful for studying transmission routes and provide new information for the control of this disease. Studies carried out in Brazil have shown that two subgenotypes circulate in our country and strains isolated from the same region demonstrated close genetic relatedness , Villar et al. 2004. In this study, we have analyzed the molecular and epidemiological relationship between HAV isolates recovered from acute cases notified in communities of surrounding region of Rio de Janeiro sampled from 1999 to 2001. PATIENTS, MATERIALS AND METHODSPopulation study -The county of Belfor Roxo covers 30 Km Northwest of the city of Rio de Janeiro with a population of approximately 435.000 inhabitants. This city is subdivided in five distri...

Informe Epidemiológico do SUS 2002; 11(3/4) : 241 -255. * Essa seção não passa pela revisão por pares.