An epidemiological study of viral hepatitis A in Beijing suburb
Wang, H.T.
Zhonghua Yu Fang Yi Xue Za Zhi 19(1): 8-10
1985
ISSN/ISBN: 0253-9624 PMID: 2983953 Document Number: 261041
The natural history of hepatitis A virus (HAV) infection was studied in a rural production brigade in the suburb of Beijing from June, 1982 to June, 1983. 491 serum samples were collected from 83.6% of the brigade members and tested for antibody to hepatitis A virus (anti-HAV) by solid-phase radioimmunoassay (SPRIA) in 1982. The prevalence rate of anti-HAV in the sampled population was 91.6 percent, and nearly 100 percent after 15 years of age. There was no significant difference in the age-specified and overall antibody prevalence rates between two sexes. The titres of 292 serum samples were measured and the results showed that they decreased with increase of age. The geometric mean titer of this group of people was 1:1560. Of 33 persons who were anti-HVA negative in June, 1982, 9 became antibody positive in June, 1983, only one of whom attended the hospital and was diagnosed as HA case. The rest did not have any symptom. The ratio between the clinical and subclinical infection of HAV is 1:8. 365 individuals who were anti-HAV positive in June, 1982 were found to harbor the antibody still in 1983. These data suggest: that HA is a disease of the children and a large proportion of adult hepatitis cases are not hepatitis A in Beijing rural areas, that anti-HAV may persist life long in those living in endemic areas and that the majority of HAV infections are subclinical.