HEV infection not evident in rodents on English pig farms

Hepatitis E virus (HEV) is the cause of hepatitis E in humans, typically an acute self-limiting hepatitis but with known risk groups.1 There is now growing awareness of locally acquired infections in industrialised countries and since 2010 there has been a yearly increase in the detection of autochthonous hepatitis E cases in England and Wales.2 While originally identified in humans, genetically diverse HEV have since been detected in an expanding list of animals. Of particular interest are genotypes HEV-1 to HEV-4 which can infect humans. HEV-3 and HEV-4 can also infect other animal species including pigs, wild boar, deer and rabbits. The cases of locally acquired hepatitis E in industrialised countries, including Great Britain (GB), are associated with HEV-3 and HEV-4.3 The transmission routes for such cases still require elucidation but include zoonotic transmission.3 Pigs are a natural reservoir of HEV-3 and HEV-4 and infection is widespread in the pig population worldwide. Zoonotic transmission of HEV through the consumption of contaminated food, including pork product is established.3 With regard to the dynamics of HEV infections on pig farms, there is particular interest in the role of rodents due to their historical association with disease transmission and their potential abundance on farms. Mice can be experimentally infected with HEV (HEV-4)4 and two …