Molecular epidemiology of hepatitis E virus in Hong Kong

Hepatitis E virus (HEV) is one of the major causes of acute and self-limiting hepatitis in human. In Hong Kong, the number of notifications increased from 26 to 62 from year 2001 to 2007. This study describes the molecular epidemiology of HEV in Hong Kong in order to determine the movement and distribution of HEV. HEV in 171 serum samples from HEV IgM positive cases from year 2001 to 2007 were amplified using RT-PCR and subjected to nucleotide sequencing. Phylogenetic analysis showed 162 of 171 HEV detected cases (94.7%) belonged to genotype IV and 8 (4.7%) to genotype I. Interestingly, a cluster of 10 cases in year 2007 that had the same sequence of HEV was identified. Epidemiological data however did not detect any relationship between these cases. Since zoonotic transmission is a well known route of HEV infection, close monitoring of the circulating HEV strains in human and food source animals may help to provide additional information on the transmission of HEV and possible source of infection in Hong Kong.