Implementing short-course zidovudine to reduce mother-infant HIV transmission in a large pilot program in Thailand.

OBJECTIVES: To describe a pilot mother-infant HIV prevention program started by the Ministry of Public Health of Thailand in July 1998 and to report on the first year of its implementation. DESIGN: Analysis of monthly summaries of data from project logbooks, simple data forms in antenatal clinics and delivery rooms, site visits and workshops, mail survey. SETTING: All 89 public hospitals in seven north-eastern provinces of Thailand. PARTICIPANTS: Childbearing women, program officials. INTERVENTIONS: Counseling and HIV testing for pregnant women, short-course antenatal zidovudine for HIV-infected pregnant women, and infant formula for their children. MAIN OUTCOME MEASURES: Proportion of women with HIV test, proportion of HIV-infected women receiving zidovudine. RESULTS: Of 75,308 women who gave birth between July 1998 and June 1999, 74,511 (98.9%) had antenatal care, 51,492 (69.1%) in the same district and 23,019 (30.9%) outside the district where they gave birth. HIV test results were available at delivery for 46,648 (61.9%) women, 410 (0.9%) of whom tested positive. Of these HIV-infected women, 259 (63.2%) participated in the zidovudine program and 6 (1.5%) received zidovudine from other sources. The proportion of women whose HIV test results were known and proportion of HIV-infected women who received zidovudine increased significantly during the year. CONCLUSIONS: A mother-infant HIV prevention program using short-course antenatal zidovudine was quickly implemented in a large region of Thailand with moderate HIV prevalence. This successful experience is leading to national implementation of a perinatal HIV prevention program in Thailand and may prompt other developing countries to start similar programs.

[HIV-1 transmission from mother to child and its prevention]. / Transmission du VIH-1 de la mère à l'enfant et sa prévention.

Mother-to-child transmission of HIV-1 can occur during pregnancy, labor/delivery, or breastfeeding. Without intervention HIV infection occurs in about 35% of infants born to HIV-infected women: 10% during pregnancy, 15% during labor/delivery, and 10% during breastfeeding. As early as 1994, the PACTG 076-ANRS 024 study documented the remarkable effectiveness of AZT in reducing mother-to-child HIV transmission from 26% to 8% in women who did not breastfeed. Since then, AZT or multiple antiretroviral therapies has been widely used in pregnant HIV-infected women in industrialized countries resulting in decline of the transmission rate to less than 3%. In developing countries where most perinatal transmissions occur, preventive treatment is more difficult to implement. Abbreviated treatment using AZT or nevirapine (NVP) in a single dose to the mother during delivery and to the newborn reduces perinatal transmission but to a lesser extent in comparison with standard treatment. Combination treatment using AZT + 3TC or AZT + NVP is more effective. Elective cesarean section has also been proposed but is not recommended in developing countries. To date the only alternative of proven efficacy for reducing transmission during breastfeeding is formula feeding, but this method may be hazardous if sanitary conditions are poor. Studies are currently under way to test the efficacy of antiretrovirals administered to the mother and/or infant in reducing HIV transmission during breastfeeding.