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Seroprevalence of hepatitis A virus antibody among children and young adults in Bangkok.

OBJECTIVE
To determine the prevalence of hepatitis A virus (HAV) antibodies in various age groups of healthy children and young adults who have not received the hepatitis A vaccine.


METHOD
Blood samples were collected from 825 volunteers aged 1-30 years from a well baby clinic and five academic institutions in the Don Mueang area from 1998 to 1999. Serum samples were assayed for specific HAV IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA) kit.


RESULTS
The seropositivity rate (12.4% overall) in each age group was as follows: 1-3 years, 7.7 per cent; 4-7 years, 6.6 per cent; 8-11 years, 12.4 per cent; 12-15 years, 10.7 per cent and 16-30 years, 25.9 per cent.


CONCLUSIONS
In the Don Mueang area of Bangkok, the majority of children (< 16 years) do not have natural immunity against HAV. The use of hepatitis A vaccine for this population should be considered. Pre-vaccination serologic screening for HAV IgG in children may not be worthwhile.