Prevalence of hepatitis A virus infection: the paradoxical example of isolated communities in the western Brazilian Amazon region.
This study evaluated the prevalence of hepatitis A virus infection in the rural area of Lábrea, in the western Brazilian Amazon region. Communities and households were selected randomly. Serum samples were analyzed by means of the immunoenzymatic method for the presence of total antibodies against HAV. The study included 1,499 individuals. The prevalence of anti-HAV was 74.6% (95% CI 72.3-76.8). Univariate analysis showed associations with age (chi-square for linear trend = 496.003, p < 0.001), presence of outside toilet (p < 0.001), history of hepatitis (p < 0.001) and family history of hepatitis (p = 0.05). After adjusting for age, HAV infection also showed an association with the number of people in the family (p = 0.03). The overall prevalence rates were high, but not more than 60% of the children under the age of ten years had already been infected. Very high prevalence was detected only within older cohorts, thus paradoxically defining this as a region with intermediate endemicity, even under the conditions of poverty encountered.
Braga
Wornei Silva Miranda
WS
Virology Unit, Tropical Medicine Foundation of Amazonas, Av. Pedro Teixeira 25, Manaus, AM, Brazil. wornei.braga@hotmail.com
Borges
Fabiane Giovanella
FG
Barros Júnior
Gildo Maia
GM
Martinho
Ana Cristina de Souza
AC
Rodrigues
Ivo Seixas
IS
Azevedo
Eliete Pereira de
EP
Davis
Gustavo Henrique Nolasco Grimmer
GH
Queiroz
Manoel Bezerra de
MB
Santos
Simone Helena Derzi dos
SH
Barbosa
Thiago Vitoriano
TV
Castilho
Márcia da Costa
Mda C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006506:Hepatitis A / Q000175:diagnosis / Q000453:epidemiology*; D035922:Hepatitis A Antibodies / Q000097:blood*; D030041:Hepatitis A virus / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012424:Rural Population; D016036:Seroepidemiologic Studies; D055815:Young Adult
D035922:Hepatitis A Antibodies