Epidemiology and molecular characterization of hepatitis B virus infection in isolated villages in the Western Brazilian Amazon.
Individuals from three isolated, rural communities in the western Brazilian Amazon were evaluated for serological markers of hepatitis B virus (HBV) infection, HBV genotype, and the presence of risk factors for infection and transmission. Of the 225 individuals studied, 79.1% had serological evidence of HBV infection; 10.2% individuals were chronic carriers for HBV surface antigen (HBsAg-positive). Analysis of risk factors indicates that HBV is transmitted mainly horizontally within the family from a chronic "active" carrier for hepatitis B "e" antigen (HBeAg-positive), though a strong possibility of vertical transmission remains. The predominance of HBV genotype F, with a higher genomic similarity between the isolates, indicated a relatively recent introduction of HBV, from a common source, to the area. This study sheds light on the HBV epidemiology in the Brazilian Amazon region and highlights the need for greater emphasis on HBV control and immunization programs.
Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Gerência de Virologia, Universidade do Estado do Amazonas, Programa de Pós-Graduação em Doenças Tropicais e Infecciosas Manaus, Amazonas, Brazil. mcastilho@fmt.am.gov.br
Márcia da Costa
Mda C
Castilho
Cintia Mara Costa de
CM
Oliveira
João Bosco de Lima
JB
Gimaque
Jorge Di Tommaso
JD
Leão
Wornei Silva Miranda
WS
Braga
D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008875:Middle Aged; D012424:Rural Population / Q000706:statistics & numerical data*; D055815:Young Adult
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens