PLoS one：降低艾滋病传播预防策略

生物谷

    据9月19日出版的《公共科学图书馆·综合》期刊称，美国匹茨堡大学医学院研究人员发现，如果撒哈拉沙漠以南非洲国家的国民坚持每天服用抗逆转录酶病毒药物，将可以减缓该地区肆虐的艾滋病传播速度。

    这些发现是以一个数学模型为基础获得的。该模型主要用于预测曝光前化学预防(PrEP)的公共卫生影响———一种使用抗逆转录酶病毒药物的艾滋病病毒（HIV）预防策略，目前它可以同治疗阳性艾滋病病毒携带者相结合使用，以防止感染从首发地点传播出去。

    这些研究人员对模型的3种情况进行了研究：一种是乐观情况，即假定使用率能达到75%，而曝光前化学预防的时间效率能达到90%；中间情况为使用率能达到50%，曝光前化学预防的时间效率能达到60%；悲观情况即只有25%的使用率，曝光前化学预防的时间效率仅达到30%。

    结果发现，在理想状况下，能够通过曝光前化学预防技术获得重大的公共卫生健康益处。如果曝光前化学预防技术能够坚持实施10年，将使撒哈拉沙漠以南非洲国家新艾滋病感染减少74%。持中间态度和悲观态度的人则认为，曝光前化学预防能够取得的成果要少得多，中间态度的人认为只会减少24.9%，而悲观者认为只有3.3%。

    研究人员从曝光前化学预防中发现一个好处———它可能会在预防艾滋病战略中起到很重要的作用，有可能对公共卫生产生重大影响，甚至可能在10年内在撒哈拉沙漠以南的非洲国家预防约320万艾滋病病例的发生。撒哈拉沙漠以南非洲国家是全球艾滋病流行的中心地带，该地区约有2240万成年人感染艾滋病，感染人口约占全球感染总人数的63%。

    曝光前化学预防是以一种假设为基础，即在感染未暴露之前采取治疗措施来延迟艾滋病病毒的传输速度。动物研究的数据表明，曝光前化学预防是一种有效防止艾滋病病毒传染的手段。（科技日报）

原始出处:

PLoS one

Received: May 28, 2007; Accepted: August 10, 2007; Published: September 19, 2007

Potential Impact of Antiretroviral Chemoprophylaxis on HIV-1 Transmission in Resource-Limited Settings

Ume L. Abbas1*, Roy M. Anderson2, John W. Mellors1

1 Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America, 2 Department of Infectious Disease Epidemiology, Imperial College, Faculty of Medicine, University of London, London, United Kingdom

Abstract

Background

The potential impact of pre-exposure chemoprophylaxis (PrEP) on heterosexual transmission of HIV-1 infection in resource-limited settings is uncertain.

Methodology/Principle Findings

A deterministic mathematical model was used to simulate the effects of antiretroviral PrEP on an HIV-1 epidemic in sub-Saharan Africa under different scenarios (optimistic, neutral and pessimistic) both with and without sexual disinhibition. Sensitivity analyses were used to evaluate the effect of uncertainty in input parameters on model output and included calculation of partial rank correlations and standardized rank regressions. In the scenario without sexual disinhibition after PrEP initiation, key parameters influencing infections prevented were effectiveness of PrEP (partial rank correlation coefficient (PRCC) = 0.94), PrEP discontinuation rate (PRCC = −0.94), level of coverage (PRCC = 0.92), and time to achieve target coverage (PRCC = −0.82). In the scenario with sexual disinhibition, PrEP effectiveness and the extent of sexual disinhibition had the greatest impact on prevention. An optimistic scenario of PrEP with 90% effectiveness and 75% coverage of the general population predicted a 74% decline in cumulative HIV-1 infections after 10 years, and a 28.8% decline with PrEP targeted to the highest risk groups (16% of the population). Even with a 100% increase in at-risk behavior from sexual disinhibition, a beneficial effect (23.4%–62.7% decrease in infections) was seen with 90% effective PrEP across a broad range of coverage (25%–75%). Similar disinhibition led to a rise in infections with lower effectiveness of PrEP (≤50%).

Conclusions/Significance

Mathematical modeling supports the potential public health benefit of PrEP. Approximately 2.7 to 3.2 million new HIV-1 infections could be averted in southern sub-Saharan Africa over 10 years by targeting PrEP (having 90% effectiveness) to those at highest behavioral risk and by preventing sexual disinhibition. This benefit could be lost, however, by sexual disinhibition and by high PrEP discontinuation, especially with lower PrEP effectiveness (≤50%).

全文链接：http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0000875

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