在马拉维利隆圭，急性和早期 HIV 感染在 HIV 传播中的作用及其对传播预防策略的影响：一项建模研究。
The role of acute and early HIV infection in the spread of HIV and implications for transmission prevention strategies in Lilongwe, Malawi: a modelling study.
机构信息
Department of Medicine, University of North Carolina, Chapel Hill, NC 27599-7030, USA.
出版信息
Lancet. 2011 Jul 16;378(9787):256-68. doi: 10.1016/S0140-6736(11)60842-8.
BACKGROUND
HIV transmission risk is higher during acute and early HIV infection than it is during chronic infection, but the contribution of early infection to the spread of HIV is controversial. We estimated the contribution of early infection to HIV incidence in Lilongwe, Malawi, and predict the future effect of hypothetical prevention interventions targeted at early infection only, chronic infection only, or both stages.
METHODS
We developed a deterministic mathematical model describing heterosexual HIV transmission, informed by detailed behavioural and viral-load data collected in Lilongwe. We included sexual contact within and outside of steady pairs and divided the infectious period into intervals to allow for changes in transmissibility by infection stage. We used a Bayesian melding approach to fit the model to HIV prevalence data collected between 1987 and 2005 at Lilongwe antenatal clinics. We assessed interventions that reduced the per-contact transmission probability to 0.00003 in people receiving them, and varied the proportion of individuals receiving the intervention in each stage.
FINDINGS
We estimated that 38.4% (95% credible interval 18.6-52.3) of HIV transmissions in Lilongwe are attributable to sexual contact with individuals with early infection. Interventions targeted at only early infection substantially reduced HIV prevalence, but did not lead to elimination, even with 100% coverage. Interventions targeted at only chronic infections also reduced HIV prevalence, but coverage levels of 95-99% were needed for the elimination of HIV. In scenarios with less than 95% coverage of interventions targeted at chronic infections, additional interventions reaching 25-75% of individuals with early infection reduced HIV prevalence substantially.
INTERPRETATION
Our results suggest that early infection plays an important part in HIV transmission in this sub-Saharan African setting. Without near-complete coverage, interventions during chronic infection will probably have incomplete effectiveness unless complemented by strategies targeting individuals with early HIV infection.
FUNDING
National Institutes of Health, University of North Carolina Center for AIDS Research.
背景
艾滋病病毒（HIV）传播的风险在急性和早期 HIV 感染期间高于慢性感染期间，但早期感染对 HIV 传播的贡献仍存在争议。我们评估了早期感染对马拉维利隆圭 HIV 发病率的贡献，并预测了仅针对早期感染、慢性感染或两个阶段的假设预防干预措施的未来效果。
方法
我们开发了一个确定性的数学模型，用于描述异性恋 HIV 传播，该模型由在利隆圭收集的详细行为和病毒载量数据提供信息。我们将性接触分为稳定伴侣内部和外部的接触，并将感染期分为多个间隔，以允许按感染阶段改变传染性。我们使用贝叶斯融合方法将模型拟合到 1987 年至 2005 年在利隆圭产前诊所收集的 HIV 流行率数据。我们评估了将接触传播概率降低至 0.00003 的干预措施，且干预措施在各阶段的覆盖比例不同。
结果
我们估计，利隆圭的 HIV 传播中有 38.4%（95%可信区间 18.6-52.3）归因于与早期感染者的性接触。仅针对早期感染的干预措施大大降低了 HIV 流行率，但即使覆盖范围达到 100%，也未能消除 HIV。仅针对慢性感染的干预措施也降低了 HIV 流行率，但需要达到 95-99%的覆盖率才能消除 HIV。在针对慢性感染的干预措施覆盖率低于 95%的情况下，针对 25-75%的早期 HIV 感染者的额外干预措施可以大大降低 HIV 流行率。
解释
我们的结果表明，在这种撒哈拉以南非洲环境中，早期感染在 HIV 传播中起着重要作用。如果没有接近全覆盖，在慢性感染期间的干预措施可能不会完全有效，除非辅以针对早期 HIV 感染者的策略。
资金来源
美国国立卫生研究院，北卡罗来纳大学艾滋病研究中心。
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