title: Hepatitis A virus subgenotypes dissemination during a community outbreak in a surrounding region of Rio de Janeiro.
abstract: From December 1999 to December 2001, 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, sequenced and analyzed. Total anti-HAV prevalence was 87.9% (203/231) and IgM anti-HAV prevalence was 38.7% (89/231). Multivariate analysis showed that individuals under 20 years old are risks groups to acquire the infection suggesting that hygienic habits of young subjects are the principal factor of transmission and so they could be the target for vaccine programs. HAV-RNA was amplified from 29 (32.5%) IgM anti-HAV positive patients and 26 samples were sequenced and classified into subgenotypes IB (8 isolates) and IA (18 isolates). Isolates classified into subgenotype IB were identical representing one distinct strain. We could observe both subgenotypes circulating during the study which suggests different sources of infection. Prophylactic measures as vaccination strategies added to improvements in hygienic and sanitary conditions would be highly effective to reduction of infection.
authors.affiliation: Laboratório de Desenvolvimento Tecnológico, Brasil. santosdl@ioc.fiocruz.br
authors.forename: Débora Regina Lopes Dos
authors.initials: DR
authors.lastname: Santos
authors.forename: Livia Melo
authors.initials: LM
authors.lastname: Villar
authors.forename: Vanessa Salete de
authors.initials: VS
authors.lastname: Paula
authors.forename: Gerson Silva de
authors.initials: GS
authors.lastname: Lima
authors.forename: Ana Maria Coimbra
authors.initials: AM
authors.lastname: Gaspar
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D006506:Hepatitis A / Q000453:epidemiology / Q000821:virology*; D035922:Hepatitis A Antibodies / Q000097:blood*; D017957:Hepatitis A Virus, Human / Q000145:classification* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D035922:Hepatitis A Antibodies; D007075:Immunoglobulin M; D012367:RNA, Viral