Proportion of new HIV infections attributable to herpes simplex 2 increases over time:: simulations of the changing role of sexually transmitted infections in sub-Saharan African HIV epidemics
Proportion of new HIV infections attributable to herpes simplex 2 increases over time:: simulations of the changing role of sexually transmitted infections in sub-Saharan African HIV epidemics
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DOI：
10.1136/sti.2006.023549
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发表时间：
2007-08-01
影响因子：
3.6
通讯作者：
Hayes, Richard J.
中科院分区：
文献类型：
--
作者：
Freeman, Esther E.;Orroth, Kate K.;Hayes, Richard J.
目的：使用模拟模型了解撒哈拉以南非洲四个城市随着时间的推移，单纯疱疹病毒2型（HSV-2）和其他性传播感染（STI）对艾滋病毒发病率的变化影响。方法：将基于个人的随机模型拟合到人口、行为和流行病学数据来自四个非洲城市的横断面人口调查（肯尼亚基苏穆;赞比亚恩多拉;喀麦隆雅温得;贝宁科托努）。为了估计一段时间内HSV-2和其他性传播感染导致的新的艾滋病毒感染的比例，将拟合模型中的艾滋病毒感染率与模型情景中的艾滋病毒感染率进行了比较，在模型情景中，性传播感染对艾滋病毒易感性和传染性的辅因子效应被移除到模拟的艾滋病毒流行的5年、10年、15年、20年和25年。归因于HSV-2感染的HIV事件的比例（模型估计的人群归因分数（PAFM））随着HIV流行的成熟而增加。在不同的城市，艾滋病流行5年后的PAFM为8-31%，但在艾滋病毒传播15年后上升到35-48%。相比之下，由于软下疳引起的艾滋病毒事件比例随着时间的推移而下降，其中艾滋病毒引入五年后影响最强，15年后则下降至没有影响。敏感性分析表明，在该模型中，复发性HSV-2溃疡对HIV发病率的影响大于原发性HSV-2溃疡，并且HSV-2对HIV感染性的影响可能比对HIV易感性的影响更重要，假设HSV-2对HIV易感性和感染性具有相似的辅因子效应。其他可治愈的性传播感染对HIV传播（梅毒，淋病和衣原体）的整体影响仍然相对恒定随着时间的推移。结论：虽然HSV-2似乎有一个有限的影响艾滋病毒的发病率在撒哈拉以南非洲艾滋病毒流行病的早期阶段，当流行病集中在核心群体，它有越来越大的影响，随着流行病的进展。在普遍的艾滋病毒流行中，可治愈性传播感染的控制方案已经到位，针对HSV-2的干预措施可能在艾滋病毒预防中发挥关键作用。
Objective: To understand the changing impact of herpes simplex 2 (HSV-2) and other sexually transmitted infections (STIs) on HIV incidence over time in four sub-Saharan African cities, using simulation models.Methods: An individual-based stochastic model was fitted to demographic, behavioural and epidemiological data from cross-sectional population-based surveys in four African cities (Kisumu, Kenya; Ndola, Zambia; Yaounde, Cameroon; and Cotonou, Benin) in 1997. To estimate the proportion of new HIV infections attributable to HSV-2 and other STIs over time, HIV incidence in the fitted model was compared with that in model scenarios in which the cofactor effect of the STIs on HIV susceptibility and infectivity were removed 5, 10, 15, 20 and 25 years into the simulated HIV epidemics.Results: The proportion of incident HIV attributable to HSV-2 infection (the model estimated population attributable fraction (PAFM)) increased with maturity of the HIV epidemic. In the different cities, the PAFM was 8-31% 5 years into the epidemic, but rose to 35-48% 15 years after the introduction of HIV. In contrast, the proportion of incident HIV attributable to chancroid decreased over time with strongest effects five years after HIV introduction, falling to no effect 15 years after. Sensitivity analyses showed that, in the model, recurrent HSV-2 ulcers had more of an impact on HIV incidence than did primary HSV-2 ulcers, and that the effect of HSV-2 on HIV infectivity may be more important for HIV spread than the effect on HIV susceptibility, assuming that HSV-2 has similar cofactor effects on HIV susceptibility and infectivity. The overall impact of other curable STIs on HIV spread (syphilis, gonorrhoea and chlamydia) remained relatively constant over time.Conclusions: Although HSV-2 appears to have a limited impact on HIV incidence in the early stages of sub-Saharan African HIV epidemics when the epidemic is concentrated in core groups, it has an increasingly large impact as the epidemic progresses. In generalised HIV epidemics where control programmes for curable STIs are already in place, interventions against HSV-2 may have a key role in HIV prevention.