Surveillance of hepatitis E virus in sewage and drinking water in a resettlement colony of Delhi: what has been the experience?

Hepatitis E virus infection is one of the major causes of hepatitis and has been responsible for many sporadic waterborne hepatitis epidemics. We studied 141 cases of viral hepatitis in the Gokulpuri area and collected the tap water, sewage water and serum samples from the individual cases of hepatitis in the community. Samples were analysed for the presence of hepatitis E virus (HEV) by RT-PCR, followed by sequencing. Forty-one out of 141 (29.08%) cases of viral hepatitis had evidence of HEV infection, detected by serology and/or RT-PCR. Six out of 141 (4.25%) sewage samples and 2 out of 141 (1.42%) drinking water samples were found to be positive for HEV RNA. The HEV isolates belonged to genotype 1. Evidence of HEV infection in sewage and drinking water samples indicates contamination of drinking water with sewage; good sanitary practice still remains a subject of alarm in the subcontinent.