Laboratory of Gastroenterology and Hepatology, São Paulo Institute of Tropical Medicine and Department of Gastroenterology, School of Medicine, University of São Paulo, Brazil.
Infect Genet Evol. 2011 Aug;11(6):1462-8. doi: 10.1016/j.meegid.2011.05.020. Epub 2011 May 27.
Hepatitis delta virus (HDV) is widely distributed and associated with fulminant hepatitis epidemics in areas with high prevalence of HBV. Several studies performed in the 1980s showed data on HDV infection in South America, but there are no studies on the viral dynamics of this virus. The aim of this study was to conduct an evolutionary analysis of hepatitis delta genotype 3 (HDV/3) prevalent in South America: estimate its nucleotide substitution rate, determine the time of most recent ancestor (TMRCA) and characterize the epidemic history and evolutionary dynamics. Furthermore, we characterized the presence of HBV/HDV infection in seven samples collected from patients who died due to fulminant hepatitis from Amazon region in Colombia and included them in the evolutionary analysis. This is the first study reporting HBV and HDV sequences from the Amazon region of Colombia. Of the seven Colombian patients, five were positive for HBV-DNA and HDV-RNA. Of them, two samples were successfully sequenced for HBV (subgenotypes F3 and F1b) and the five samples HDV positive were classified as HDV/3. By using all HDV/3 available reference sequences with sampling dates (n=36), we estimated the HDV/3 substitution rate in 1.07 × 10(-3) substitutions per site per year (s/s/y), which resulted in a time to the most recent common ancestor (TMRCA) of 85 years. Also, it was determined that HDV/3 spread exponentially from early 1950s to the 1970s in South America. This work discusses for the first time the viral dynamics for the HDV/3 circulating in South America. We suggest that the measures implemented to control HBV transmission resulted in the control of HDV/3 spreading in South America, especially after the important raise in this infection associated with a huge mortality during the 1950s up to the 1970s. The differences found among HDV/3 and the other HDV genotypes concerning its diversity raises the hypothesis of a different origin and/or a different transmission route.
乙型肝炎 delta 病毒（HDV）广泛分布，并与乙型肝炎病毒（HBV）高发地区的暴发性肝炎流行有关。20 世纪 80 年代进行的几项研究显示了南美洲 HDV 感染的数据，但没有关于该病毒病毒动力学的研究。本研究旨在对在南美洲流行的乙型肝炎 delta 基因型 3（HDV/3）进行进化分析：估计其核苷酸取代率，确定最近共同祖先（TMRCA）的时间，并描述其流行病史和进化动态。此外，我们还对从哥伦比亚亚马逊地区因暴发性肝炎死亡的 7 名患者中采集的样本进行了 HBV/HDV 感染的特征描述，并将其纳入进化分析。这是首次报道来自哥伦比亚亚马逊地区的 HBV 和 HDV 序列的研究。在这 7 名哥伦比亚患者中，有 5 名 HBV-DNA 和 HDV-RNA 阳性。其中，有 2 个样本成功进行了 HBV （亚基因型 F3 和 F1b）测序，5 个 HDV 阳性样本被归类为 HDV/3。通过使用所有具有采样日期的 HDV/3 可用参考序列（n=36），我们估计 HDV/3 的取代率为每年每位点 1.07×10(-3) 个取代（s/s/y），这导致最近共同祖先（TMRCA）的时间为 85 年。此外，还确定了 HDV/3 从 20 世纪 50 年代初到 70 年代在南美洲呈指数传播。这项工作首次讨论了在南美洲循环的 HDV/3 的病毒动力学。我们认为，为控制 HBV 传播而采取的措施导致了 HDV/3 在南美洲的传播得到控制，尤其是在 20 世纪 50 年代至 70 年代期间，由于与这种感染相关的大量死亡率，这种感染的发生率大幅上升之后。HDV/3 与其他 HDV 基因型在多样性方面的差异提出了不同起源和/或不同传播途径的假设。
