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

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 103; no. 3; pp. 254 - 258
• Main Authors: dos Santos, Débora Regina Lopes, Villar, Livia Melo, de Paula, Vanessa Salete, de Lima, Gerson Silva, Gaspar, Ana Maria Coimbra
• Format: Journal Article
• Language: English
• Published: Brazil Fundação Oswaldo Cruz, Fiocruz 01.05.2008; Instituto Oswaldo Cruz, Ministério da Saúde; Fundação Oswaldo Cruz (FIOCRUZ)
• Subjects: Acute Disease; Adolescent; Adult; Aged; Brazil - epidemiology; Child; Child, Preschool; co-circulation of subgenotypes IA and IB; Disease Outbreaks; Enzyme-Linked Immunosorbent Assay; Female; Genotype; Hepatitis A - epidemiology; Hepatitis A - virology; Hepatitis A Antibodies - blood; Hepatitis A virus; Hepatitis A Virus, Human - classification; Hepatitis A Virus, Human - genetics; Hepatitis A Virus, Human - immunology; Humans; Immunoglobulin M - blood; Infant; Infant, Newborn; Male; Middle Aged; molecular epidemiology; PARASITOLOGY; Phylogeny; Prevalence; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; RNA, Viral - analysis; TROPICAL MEDICINE; Brazil; molecular epidemiology; hepatitis A virus; co-circulation of subgenotypes IA and IB
• ISSN: 1678-8060; 0074-0276; 0074-0276; 1678-8060
• DOI: 10.1590/S0074-02762008000300005

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.