Nebraska Center for Virology and School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0900, USA.
AIDS. 2010 Jun 19;24(10):1577-82. doi: 10.1097/QAD.0b013e32833999e1.
To reconstruct the onset date and evolutionary history of the HIV-1 subtype C epidemic in Ethiopia - one of the earliest recorded subtype C epidemics in the world.
HIV-1 C env sequences with a known sampling year isolated from HIV-1 positive patients from Ethiopia between 1984 and 2003.
Evolutionary parameters including origin and demographic growth patterns were estimated using a Bayesian coalescent-based approach under either strict or relaxed molecular clock models.
Bayesian evolutionary analysis indicated a most recent common ancestor date of 1965 with three distinct epidemic growth phases. Regression analysis of root-to-tip distances revealed a highly similar estimate for the origin of the clade. In addition, we reveal that the HIV-1C epidemic in Ethiopia has grown at a faster rate than the epidemic of subtype C in sub-Saharan Africa.
Reconstruction of the epidemic history in Ethiopia revealed that subtype C likely originated from either a single lineage or multiple descendents in the late 1960s or early 1970s where it grew exponentially throughout the mid-1970s and early 1980s, corresponding to a wave of urbanization and migration. In light of these findings, we suggest that subtype C strains were circulating at least a decade before previous estimates and the first recognition of symptomatic patients in Ethiopia. The timing of the Ethiopian epidemic is also in agreement with similar HIV-1 epidemics in sub-Saharan Africa.
重建埃塞俄比亚 HIV-1 亚型 C 流行的起始日期和进化史——这是世界上最早记录的 HIV-1 亚型 C 流行之一。
1984 年至 2003 年间从埃塞俄比亚 HIV-1 阳性患者中分离出具有已知采样年份的 HIV-1 C env 序列。
使用基于贝叶斯合并的方法，在严格或宽松的分子钟模型下，估计包括起源和人口增长模式在内的进化参数。
贝叶斯进化分析表明，最近的共同祖先日期为 1965 年，有三个不同的流行增长阶段。对根到尖端距离的回归分析显示，枝系的起源有非常相似的估计。此外，我们还发现，埃塞俄比亚的 HIV-1C 流行速度比撒哈拉以南非洲的 C 亚型流行速度更快。
埃塞俄比亚流行史的重建表明，C 型可能起源于 20 世纪 60 年代末或 70 年代初的单一谱系或多个后裔，在 70 年代中期和 80 年代初期呈指数增长，与城市化和移民浪潮相对应。鉴于这些发现，我们认为 C 型株至少在之前的估计和埃塞俄比亚首例症状患者出现前十年就已流行。埃塞俄比亚流行的时间也与撒哈拉以南非洲类似的 HIV-1 流行相一致。
