HEPATITIS E VIRUS IN SEWAGE AND IN SPORADIC ACUTE HEPATITIS CASES IN ISRAEL

Background and aims: Hepatitis E virus (HEV) is yearly responsible for approximately 20 million acute hepatitis cases worldwide. In Israel, there is no monitoring for HEV, although the prevalence of anti HEV antibodies is 10.6%. Our aim was to assess environmental and patient samples for HEV during 2013-2015.

Methods: 169 sewage samples and 49 samples from hospitalized patients that presented with acute hepatitis were analyzed. Real-time PCR was used for HEV diagnosis and HEV genotype was determined by sequencing.

Results: Altogether, 8.3% (14/169 samples) of all sewage samples were HEV positive. Positive samples were found in Haifa (11/18 samples), Tel Aviv (2/29 samples) and Beer sheva (1/38 samples) areas, in regions with good sanitary conditions and middle-high socioeconomic population. No seasonal pattern was identified. 6.1% (3/49) of patients with acute hepatitis were HEV positive. Genotype analysis revealed G3 HEV sequences in sewage samples and G1 HEV in patients.

Conclusions: HEV G3 was identified only in sewage samples. Though mostly in Haifa region, HEV G3 sequences were also found in other areas suggesting a wider spread in Israel. The few clinical cases, all travelers returning from endemic countries, were infected with HEV G1. The consistent identification of HEV G3 in sewage, the absence of any patients with HEV G3 together with the high prevalence of anti HEV antibodies may suggest silent circulation or lack of awareness to HEV and justifies better surveillance for this emerging pathogen. The possibility of zoonotic HEV G3 infection should also be explored.