Hepatitis A virus subgenotypes dissemination during a community outbreak in a surrounding region of Rio de Janeiro

Abstract

, 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...

First report of a human autochthonous hepatitis E virus infection in Brazil

“…31 In urban areas such as the metropolitan area of Rio de Janeiro, outbreaks of hepatitis A have been described due to the exposure of susceptible population. [32][33][34][35] Nevertheless, epidemic HEV infections have not been yet found. The human HEV isolate (Brazil h1) from this study clustered with two swine strains (Brazil sw1 and Brazil sw2) also from Rio de Janeiro and a human Japanese isolate (E21-YKH00) from an sporadic acute case of genotype 3 and subtype 3b according to a classification proposed by Lu and Li.…”

High prevalence of hepatitis A in indigenous population in north Brazil

“…Some studies demonstrated that HAV prevalence is associated to water access and monthly income [19][20][21]. HAV dispersion could increase the probability of outbreaks as reported in several communities [5,[22][23][24] and favor person-to-person transmission of HAV [25] that could be one of the main route of HAV dissemination among person that have strict contact, as happening in the indigenous culture.…”

Investigação de surto de hepatite A no Município de Ibiracatu, Estado de Minas Gerais, Brasil, 2008

“…[9][10][11] As condições socioeconômicas estão diretamente relacionadas com a incidência da doença, destacando-se que a oferta de água tratada e a canalização de esgotos nos centros urbanos são pontos fundamentais para minimizar o risco de adoecimento. [12][13][14] Apesar da falta de saneamento, regiões rurais têm apresentado taxas de infecção mais baixas que regiões urbanas. 15,16 Na cidade de Limeira, São Paulo, Brasil, constatouse que 48,0% das amostras de água coletada de esgotos domésticos ao longo do período de estudo foram positivas para o vírus da hepatite A, evidenciando que a falta de tratamento adequado desse material antes da disposição no meio ambiente facilita o ciclo de contágio da doença.…”