Changing epidemiology of hepatitis A in Brazil: reassessing immunization policy.
Recent studies have shown that the prevalence of antibody to hepatitis A virus (HAV) is decreasing in several Latin American countries. Brazil is a very large and heterogeneous country, showing striking regional differences. With regard to sanitary facilities, 81.7% of the districts in the south-eastern region have sewage systems, compared with only 5.8% in the northern region. Results of sero-epidemiological studies and reported hepatitis A outbreaks indicate a change in the epidemiological pattern of hepatitis A in the country. Individuals, especially those under the age of 10, are mostly unprotected from HAV infection, regardless of their socioeconomic status. During 2000-2005, approximately 14 000-21 000 cases of hepatitis A were reported annually in Brazil, a rate of 7.5-11 cases per 100 000 population. Nationwide, hepatitis A mortality rates declined progressively from 1980 to 2002. As fatal cases constitute a small, but predictable, portion of all acute hepatitis A cases, which are in turn part of the total number of HAV infections, these data suggest that there has been a decline in HAV circulation in all Brazilian regions over the last two decades. Taken together these facts point out that the epidemiological pattern of hepatitis A is changing in Brazil. Besides improvements in sanitary conditions in the poorest Brazilian regions, the introduction of hepatitis A vaccination of young children could be a strategy for controlling HAV infection in the country.
Vitral
C L
CL
Departamento de Microbiologia e Parasitologia, Instituto Biomédico, UFF, Niterói, RJ, Rio de Janeiro, Brazil. clvitral@ioc.fiocruz.br
Souto
F J D
FJ
Gaspar
A M C
AM
D001938:Brazil / Q000453:epidemiology; D004196:Disease Outbreaks; D006291:Health Policy; D006506:Hepatitis A / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D007114:Immunization; D015994:Incidence; D015995:Prevalence