Meldal Birgit H M, Moula Najet Mojaat, Barnes If H A, Boukef Kamel, Allain Jean-Pierre
Division of Transfusion Medicine, Department of Haematology, University of Cambridge, Cambridge Blood Centre, Long Road, Cambridge CB2 0PT, UK.
Tunisian National Blood Centre, Tunis, Tunisia.
J Gen Virol. 2009 Jul;90(Pt 7):1622-1628. doi: 10.1099/vir.0.009738-0. Epub 2009 Apr 1.
Tunisia is a medium-level epidemic country for hepatitis B virus (HBV). This study characterizes, for the first time, full genome HBV strains from Tunisia. Viral load quantification and phylogenetic analyses of full genome or pre-S/S sequences were performed on 196 hepatitis B surface antigen (HBsAg)-positive plasma samples from Tunisian blood donors. The median viral load was 64.65 IU ml(-1) (range<5-7.7x10(8) IU ml(-1)) and 89% of samples had viral loads below 10,000 IU ml(-1). Fifty-nine strains formed a novel subgenotype D7, 41 strains clustered in subgenotype D1, seven strains in subgenotype A2 and one strain in genotype C. The novel subgenotype D7 was defined by maximum Bayesian posterior probability, a genetic divergence from other HBV/D subgenotypes by >4% and a stronger HBV/E signal in the X to core genes than subgenotype D1. In conclusion, HBV/D is dominant in asymptomatic Tunisian HBsAg carriers and a novel subgenotype, D7, was the most common subgenotype found in this population.
突尼斯是乙型肝炎病毒（HBV）的中度流行国家。本研究首次对来自突尼斯的HBV全基因组毒株进行了特征分析。对196份来自突尼斯献血者的乙型肝炎表面抗原（HBsAg）阳性血浆样本进行了全基因组或前S/S序列的病毒载量定量和系统发育分析。病毒载量中位数为64.65 IU/ml（范围<5 - 7.7×10⁸ IU/ml），89%的样本病毒载量低于10,000 IU/ml。59株形成了一个新的D7亚基因型，41株聚集在D1亚基因型中，7株在A2亚基因型中，1株在C基因型中。新的D7亚基因型通过最大贝叶斯后验概率定义，与其他HBV/D亚基因型的遗传差异>4%，并且在X至核心基因中比D1亚基因型具有更强的HBV/E信号。总之，HBV/D在无症状的突尼斯HBsAg携带者中占主导地位，新的D7亚基因型是该人群中最常见的亚基因型。
