Dunn D T, Tess B H, Rodrigues L C, Ades A E
Institute of Child Health, University College London Medical School, UK.
AIDS. 1998 Nov 12;12(16):2211-6. doi: 10.1097/00002030-199816000-00017.
To examine the implications of variation in maternal infectivity on the timing of mother-to-child HIV transmission through breastfeeding.
A mathematical model of mother-to-child HIV transmission was developed that incorporates two main features: (i) the fetus/child potentially experiences a series of exposures (in utero, intrapartum, and via breastmilk) to HIV; and (ii) variation in maternal infectivity. The model was estimated from different sources of epidemiological data: a retrospective cohort study of children born to HIV-1-infected women in Sao Paulo State, Brazil, the International Registry of HIV-Exposed Twins, and the AIDS Clinical Trials Group 076 trial, which assessed the effectiveness of zidovudine in preventing mother-to-child HIV transmission.
Variation in maternal infectivity results in higher average risk of breastfeeding-related transmission in the early stages of breastfeeding than in the late stages, even in the absence of a direct relationship between transmission risk and the age of the child. However, the available data were unable to resolve the quantitative importance of this mechanism.
Our model has helped identify a previously unrecognized determinant of the timing of breastfeeding-related HIV transmission, which may have adverse implications for the effectiveness of certain interventions to reduce mother-to-child HIV transmission such as maternal antiretroviral therapy in breastfeeding populations and the early cessation of breastfeeding.
研究母亲感染性的差异对通过母乳喂养实现母婴传播艾滋病毒时间的影响。
建立了一个母婴传播艾滋病毒的数学模型，该模型包含两个主要特征：（i）胎儿/儿童可能经历一系列接触艾滋病毒的过程（宫内、分娩时和通过母乳）；（ii）母亲感染性的差异。该模型是根据不同来源的流行病学数据估算得出的：对巴西圣保罗州感染艾滋病毒-1的妇女所生孩子的一项回顾性队列研究、艾滋病毒暴露双胞胎国际登记处以及艾滋病临床试验组076试验，后者评估了齐多夫定在预防母婴传播艾滋病毒方面的有效性。
即使在传播风险与儿童年龄之间不存在直接关系的情况下，母亲感染性的差异导致母乳喂养早期与母乳喂养相关的传播平均风险高于后期。然而，现有数据无法确定这一机制的定量重要性。
我们的模型有助于确定母乳喂养相关艾滋病毒传播时间的一个此前未被认识的决定因素，这可能对某些减少母婴传播艾滋病毒干预措施的有效性产生不利影响，如在母乳喂养人群中进行母亲抗逆转录病毒治疗以及提前停止母乳喂养。
