a high variability of mixed infections and recent recombinations of hepatitis b virus in laos最近的高可变性的混合感染和乙型肝炎病毒在老挝的再组合.pdfVIP

A High Variability of Mixed Infections and Recent Recombinations of Hepatitis B Virus in Laos 1 2 3 2 4 Iris E. Andernach , Prapan Jutavijittum , Bounthome Samountry , Amnat Yousukh , Te Thammavong , ¨ 1 1 Judith M. Hubschen , Claude P. Muller * ´ 1 Institute of Immunology, Centre de Recherche Public-Sante/National Public Health Laboratory, Luxembourg, Luxembourg, 2 Department of Pathology, Chiang Mai University, Chiang Mai, Thailand, 3 Department of Pathology, University of Health Sciences, Vientiane, Lao PDR, 4 National Blood Transfusion Centre, Lao Red Cross, Vientiane, Lao PDR Abstract In Lao PDR, where more than 8% of the population are chronic carriers of HBsAg, multiple genotypes and subgenotypes co- circulate and are prone to generate recombinant viruses. Phylogenetic analyses of multiple clones per donor revealed mixed infections of subgenotypes B1, B2, B4, C1, C5, I1 and I2 in almost 6% of HBsAg positive rejected blood donors. Recombination analyses and distance calculations furthermore showed that about 65% (17/26) of the mixed infected donors showed recombinations in the S-gene alone, involving the predominant genotypes B and C. These results suggest that, at least in Laos, hepatitis B virus (HBV) mixed infections lead to frequent recombinations. In many donors with recombinant strains, the recombinant fragment and a non-recombinant strain of the same genotype co-existed (127/185 analysed recombinant fragments). For a large proportion of these (60/127), the most closely related known virus was found,