Section of Molecular Virology, Department of Experimental Medical Science, Lund University, Lund, Sweden.
PLoS One. 2011 Feb 18;6(2):e17025. doi: 10.1371/journal.pone.0017025.
The HIV-1 epidemic in West Africa has been dominated by subtype A and the recombinant form CRF02_AG. Little is known about the origins and the evolutionary history of HIV-1 in this region. We employed Maximum likelihood and Bayesian methods in combination with temporal and spatial information to reconstruct the HIV-1 subtype distribution, demographic history and migration patterns over time in Guinea-Bissau, West Africa. We found that CRF02_AG and subsubtype A3 were the dominant forms of HIV-1 in Guinea-Bissau and that they were introduced into the country on at least six different occasions between 1976 and 1981. These estimates also corresponded well with the first reported HIV-1 cases in Guinea-Bissau. Migration analyses suggested that (1) the HIV-1 epidemic started in the capital Bissau and then dispersed into more rural areas, and (2) the epidemic in Guinea-Bissau was connected to both Cameroon and Mali. This is the first study that describes the HIV-1 molecular epidemiology in a West African country by combining the results of subtype distribution with analyses of epidemic origin and epidemiological linkage between locations. The multiple introductions of HIV-1 into Guinea-Bissau, during a short time-period of five years, coincided with and were likely influenced by the major immigration wave into the country that followed the end of the independence war (1963-1974).
在西非，HIV-1 流行主要由亚型 A 和重组型 CRF02_AG 引起。对于该地区 HIV-1 的起源和进化历史，人们知之甚少。我们采用最大似然法和贝叶斯法，结合时间和空间信息，重建了 HIV-1 亚型分布、人口历史和在时间上的迁移模式在西非几内亚比绍。我们发现 CRF02_AG 和亚亚型 A3 是几内亚比绍 HIV-1 的主要形式，它们在 1976 年至 1981 年期间至少有六次不同的时间进入该国。这些估计也与几内亚比绍首次报告的 HIV-1 病例相符。迁移分析表明：（1）HIV-1 疫情始于首都比绍，然后扩散到更多的农村地区；（2）几内亚比绍的疫情与喀麦隆和马里有关。这是第一项通过将亚型分布结果与疫情起源和地点之间的流行病学联系分析相结合，描述西非国家 HIV-1 分子流行病学的研究。HIV-1 在五年的短时间内多次传入几内亚比绍，这与独立战争结束后（1963-1974 年）该国的主要移民潮相吻合，并可能受到其影响。
