Comparative genomics of hepatitis A virus, hepatitis C virus, and hepatitis E virus provides insights into the evolutionary history of Hepatovirus species

Wassenaar, Trudy M.; Jun, Se-Ran; Robeson, Michael; Ussery, David W.

Hepatitis E virus is the latest discovered virus of the three species considered here, but it actually is the most common cause of acute viral hepatitis in humans (Kamar et al., 2017) , with an estimated 20 million novel infections worldwide, of which 3 million are symptomatic and around 70,000 are lethal; these may be underestimates, even in developed countries (Webb & Dalton, 2019) . Hepatitis E virus is spread via the fecal-oral route as well as by animal contact or via contaminated food of animal origin; parenteral transmission has also been described. Most infections are self-limiting. The genome of HEV is 7.2 kb with a GC content of 56%, and the 5′-untranscribed region is capped. The ssRNA(+) genome encodes a large polypeptide of which it is uncertain whether it is active as such or first processed into separate proteins with distinct functions, and 2 shorter proteins, translated from partly overlapping open reading frames (recently reviewed in Primadharsini, Nagashima, & Okamoto, 2019) .