Seroepidemiology of hepatitis A in voluntary blood donors from Pune, western India (2002 and 2004-2005).

Recently, a changing pattern of hepatitis A epidemiology has been reported in the Indian population indicating a rise in the rate of hepatitis A infection among adults. The study's objective was to assess anti-HAV prevalence in voluntary blood donors from middle and high socioeconomic strata. Serum samples collected from voluntary blood donors from Pune city and its suburbs in the years 2002 and 2004-2005 were tested for anti-HAV IgG antibodies. Serum samples collected during 2004-2005 were examined for anti-HAV IgM antibodies. Positive samples were tested for HAV-RNA. Agewise anti-HAV positivity was significantly low in adults aged 18-25 years (90.4%) compared to those aged >25 years (97.4%) (P<0.01). A decline in anti-HAV prevalence was significant in 2004-2005 compared to that in 2002 (96.5% vs. 92.1%) (P<0.01). Overall, in both adult age groups, the proportion of anti-HAV positivity was remarkably low in the high socioeconomic group (HSG) (88.96%) compared to that of the middle socioeconomic group (MSG) (95.86%) (P<0.01). Anti-HAV IgM positivity was not significant (~1%), however, presence of HAV-RNA in one of the samples indicated the possibility of horizontal transmission of HAV. Increase in seronegativity to HAV in HSG implicates a rise in the susceptible pool and indicates the need for vaccination against hepatitis A.