An outbreak of hepatitis E virus infection caused by genotype 1 in an urban setting in eastern India: a probe into risk factors for transmission.

The study was undertaken to find out the cause and etiology of an outbreak presumed to be due to water contamination that caused high morbidity in the western part of the state of Odisha during May, 2014. In this investigation 56 blood samples were collected and tested for HEV IgM through ELISA. Blood sample of 22 patients collected within 1 weeks post onset of symptoms and were subjected to RT-PCR and sequencing followed by phylogenetic analysis. Water samples were also analyzed for viral and bacterial contamination. A total of 290 individuals were examined for suspected jaundice. Out of 56 blood samples in 41 (73.2%) IgM for HEV was found. 12 samples out of 22 early phase samples were positive for RT-PCR and through phylogenetic analysis all were found to be of Genotype 1 and subtype A. This large outbreak was confirmed due to Hepatitis E virus and transmission was fast due to contamination of drinking water sources and lack of hygienic practices. The outcome of this investigation has created alertness among state health and municipal authorities to be prepared for the similar kind of situation for other part of the state.