SEROEPIDEMIOLOGY OF WATER-BORNE HEPATITIS IN INDIA AND EVIDENCE FOR A3RD ENTERICALLY-TRANSMITTED HEPATITIS AGENT

Many epidemics of water-borne hepatitis have occurred throughout India . These were thought to be epidemics of hepatitis A until 1980, when e vidence for an enterically transmitted non-A, non-B hepatitis was firs t reported. Subsequently, hepatitis E virus was discovered and most re cent epidemics of enterically transmitted non-A, non-B hepatitis have been attributed to hepatitis E virus infection. However, only a limite d number of cases have been confirmed by immuno electron microscopy, p olymerase chain reaction, or seroconversion. In the present study we h ave performed a retrospective seroepidemiologic study of 17 epidemics of water-borne hepatitis in India. We have confirmed that 16 of the 17 epidemics were caused at least in part by serologically closely relat ed hepatitis E viruses. However, one epidemic, in the Andaman Islands, and possibly a significant minority of cases in other epidemics, appe ars to have been caused by a previously unrecognized hepatitis agent.