Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
J Acquir Immune Defic Syndr. 2012 Apr 1;59(4):417-25. doi: 10.1097/QAI.0b013e3182432f27.
The prevention of mother-to-child transmission (PMTCT) of HIV has been focused mainly on women who are HIV positive at their first antenatal visit, but there is uncertainty regarding the contribution to overall transmission from mothers who seroconvert after their first antenatal visit and before weaning.
A mathematical model was developed to simulate changes in mother-to-child transmission of HIV over time, in South Africa. The model allows for changes in infant feeding practices as infants age, temporal changes in the provision of antiretroviral prophylaxis and counseling on infant feeding, as well as temporal changes in maternal HIV prevalence and incidence.
The proportion of mother-to-child transmission (MTCT) from mothers who seroconverted after their first antenatal visit was 26% [95% confidence interval (CI): 22% to 30%] in 2008, or 15,000 of 57,000 infections. It is estimated that by 2014, total MTCT will reduce to 39,000 per annum, and transmission from mothers seroconverting after their first antenatal visit will reduce to 13,000 per annum, accounting for 34% (95% CI: 29% to 39%) of MTCT. If maternal HIV incidence during late pregnancy and breastfeeding were reduced by 50% after 2010, and HIV screening were repeated in late pregnancy and at 6-week immunization visits after 2010, the average annual number of MTCT cases over the 2010-2015 period would reduce by 28% (95% CI: 25% to 31%), from 39,000 to 28,000 per annum.
Maternal seroconversion during late pregnancy and breastfeeding contributes significantly to the pediatric HIV burden and needs greater attention in the planning of prevention of MTCT programs.
母婴传播（PMTCT）的预防主要集中在首次产前检查时 HIV 阳性的妇女，但对于首次产前检查后至断奶前发生血清转换的母亲对总体传播的贡献尚不确定。
在南非，建立了一个数学模型来模拟 HIV 母婴传播随时间的变化。该模型允许随着婴儿年龄的变化改变婴儿喂养方式，以及随着时间的推移改变抗逆转录病毒预防和婴儿喂养咨询的提供，以及孕产妇 HIV 流行率和发病率的变化。
2008 年，首次产前检查后发生血清转换的母亲母婴传播的比例为 26%（95%置信区间：22%至 30%），即 57000 例感染中有 15000 例。估计到 2014 年，总母婴传播将减少到每年 39000 例，首次产前检查后发生血清转换的母亲母婴传播将减少到每年 13000 例，占母婴传播的 34%（95%置信区间：29%至 39%）。如果 2010 年后，妊娠晚期和哺乳期的母婴 HIV 发病率降低 50%，并在 2010 年后的妊娠晚期和 6 周免疫接种时重复 HIV 筛查，2010-2015 年期间每年平均母婴传播病例数将减少 28%（95%置信区间：25%至 31%），从每年 39000 例降至 28000 例。
妊娠晚期和哺乳期的母亲血清转换对儿科 HIV 负担有重大影响，需要在 PMTCT 规划中更加重视。
