Avian Hepatitis E Virus in Chickens, Taiwan, 2013

Ingrid W.-Y. Hsu and Hsiang-Jung Tsai

Author affiliations: National Taiwan University, Taipei, Taiwan (I.W.-Y. Hsu, H.-J. Tsai); and Council of Agriculture, New Taipei City, Taiwan (H.-J. Tsai)

Abstract

A previously unidentified strain of avian hepatitis E virus (aHEV) is now endemic among chickens in Taiwan. Analysis showed that the virus is 81.5%–86.5% similar to other aHEVs. In Taiwan, aHEV infection has been reported in chickens without aHEV exposure, suggesting transmission from asymptomatic cases or repeated introduction through an unknown common source(s).

Avian hepatitis E virus (aHEV) was first isolated from chickens with big liver and spleen disease or hepatitis-splenomegaly syndrome (1,2). aHEV infection in chickens can cause death and reduce egg production, resulting in economic losses in the poultry industry (3). The zoonotic characteristic of aHEV have not been verified with certainty (4); however, the virus may have public health implications related to the consumption of contaminated poultry eggs and meat, the use of poultry viscera as a culinary delicacy, and the handling of poultry.

In Taiwan, the prevalence of aHEV in avian livestock has been increasing, but the causative strain has not been known. To increase our knowledge of this growing problem, we determined the seroprevalence of aHEV antibody in chickens in Taiwan and then isolated the infecting virus and sequenced and phylogenetically analyzed its full genome to better determine the origin and evolutionary status of the virus.