Dube Sabada, Boily Marie-Claude, Mugurungi Owen, Mahomva Agnes, Chikhata Frank, Gregson Simon
Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
J Acquir Immune Defic Syndr. 2008 May 1;48(1):72-81. doi: 10.1097/QAI.0b013e31816bcdbb.
The World Health Organization recommends a single-dose nevirapine (NVP) regimen for prevention of mother-to-child transmission (PMTCT) of HIV in settings without the capacity to deliver more complex regimens, but the population-level impact of this intervention has rarely been assessed.
A decision analysis model was developed, parameterized, and applied using local epidemiologic and demographic data to estimate vertical transmission of HIV and the impact of the PMTCT program in Zimbabwe up to 2005.
Between 1980 and 2005, of approximately 10 million children born in Zimbabwe, a cumulative 504,000 (range: 362,000 to 665,000) were vertically infected with HIV; 59% of these infections occurred in nonurban areas. Mother-to-child transmission (MTCT) of HIV decreased from 8.2% (range: 6.0% to 10.7%) in 2000 to 6.2% (range: 4.9% to 8.9%) in 2005, predominantly attributable to declining maternal HIV prevalence rather than to the PMTCT program. Between 2002 and 2005, the single-dose NVP PMTCT program may have averted 4600 (range: 3900 to 7800) infections. In 2005, 32% (range: 26% to 44%) and 4.0% (range: 2.7% to 6.2%) of infections were attributable to breast-feeding and maternal seroconversion, respectively, and the PMTCT program reduced infant infections by 8.8% (range: 5.5% to 12.1%). Twice as many infections could have been averted had a more efficacious but logistically more complex NVP + zidovudine regimen been implemented with similar coverage (50%) and acceptance (42%).
The decline in MTCT from 2000 to 2005 is attributable more to the concurrent decrease in HIV prevalence in pregnant women than to PMTCT at the current level of rollout. To improve the impact of PMTCT, program coverage and acceptance must be increased, especially in rural areas, and local infrastructure must then be strengthened so that single-dose NVP can be replaced with a more efficacious regimen.
世界卫生组织建议，在没有能力实施更复杂方案的情况下，采用单剂量奈韦拉平（NVP）方案预防艾滋病毒母婴传播（PMTCT），但这一干预措施对人群的影响鲜有评估。
利用当地的流行病学和人口统计学数据，建立、参数化并应用了一个决策分析模型，以估计艾滋病毒的垂直传播以及截至2005年津巴布韦PMTCT项目的影响。
1980年至2005年期间，津巴布韦出生的约1000万儿童中，累计有50.4万（范围：36.2万至66.5万）儿童垂直感染艾滋病毒；其中59%的感染发生在非城市地区。艾滋病毒母婴传播（MTCT）从2000年的8.2%（范围：6.0%至10.7%）降至2005年的6.2%（范围：4.9%至8.9%），这主要归因于孕妇艾滋病毒感染率的下降，而非PMTCT项目。2002年至2005年期间，单剂量NVP PMTCT项目可能避免了4600例（范围：3900至7800例）感染。2005年，分别有32%（范围：26%至44%）和4.0%（范围：2.7%至6.2%）的感染归因于母乳喂养和母亲血清转化，PMTCT项目使婴儿感染率降低了8.8%（范围：5.5%至12.1%）。如果实施一种更有效但在后勤方面更复杂的NVP+齐多夫定方案，且覆盖率（50%）和接受率（42%）相似，那么可以避免的感染数量将是原来的两倍。
2000年至2005年期间MTCT的下降更多归因于孕妇艾滋病毒感染率的同时下降，而非当前推广水平下的PMTCT。为了提高PMTCT的影响，必须提高项目覆盖率和接受率，尤其是在农村地区，然后必须加强当地基础设施，以便能用更有效的方案取代单剂量NVP。
