a possible geographic origin of endemic hepatitis c virus 6a in hong kong evidences for the association with vietnamese immigration可能流行的地理起源丙型肝炎病毒在香港6依据协会与越南移民.pdfVIP

A Possible Geographic Origin of Endemic Hepatitis C Virus 6a in Hong Kong: Evidences for the Association with Vietnamese Immigration 1 2 3 4 Xiaoming Zhou *, Paul K. S. Chan , John S. Tam , Julian W. Tang 1 Department of Epidemiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China, 2 Department of Microbiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region, China, 3 World Health Organization, Geneva, Switzerland, 4 Department of Laboratory Medicine, National University Hospital, Singapore Abstract Background: Hepatitis C virus (HCV) 6a accounts for 23.6% of all HCV infections of the general population and 58.5% of intravenous drug users in Hong Kong. However, the geographical origin of this highly predominant HCV subgenotype is largely unknown. This study explores a hypothesis for one possible transmission route of HCV 6a to Hong Kong. Methods: NS5A sequences derived from 26 HCV 6a samples were chosen from a five year period (1999–2004) from epidemiologically unrelated patients from Hong Kong. Partial-NS5A sequences (513-bp from nt 6728 to 7240) were adopted for Bayesian coalescent analysis to reconstruct the evolutionary history of HCV infections in Hong Kong using the BEAST v1.3 program. A rooted phylogenetic tree was drawn for these sequences by alignment with reference Vietnamese sequences. Demographic data were accessed from ‘‘The Statistic Yearbooks of Hong Kong’’. Results: Bayesian coalescent analysis showed that the rapid increase in 6a infections, which had increased more than 90- fold in Hong Kong from 1986 to 1994 correlated to two peaks of Vietnamese immigration to Hong Kong from 1978 to 1997. The second peak, which occurred from 1987 thr