HIV-1 mother-to-child transmission, post-test counselling, and antiretroviral prophylaxis in Northern Viet Nam: a prospective observational study.

Background: Pregnant women fear being identified as HIV-1-infected and this has hampered prevention programmes and the calculation of transmission rates in Viet Nam. We introduced post-test counselling, antiretroviral prophylaxis, and formula feeding, and determined the vertical transmission rate in parts of Northern Viet Nam.

Methods: HIV infection was identified in 234 pregnant women; 182 (77.8%) accepted follow-up of their children. Counselling was given on 3-7 occasions for altogether approximately 6 h on antiretroviral prophylaxis and formula feeding to avoid transmission, and on the importance of surveillance of the child. All children were formula-fed. A polymerase chain reaction (PCR) was used for the diagnosis of HIV-1 in the children. One hundred and thirty-five of the 182 mothers allowed ≥ 3 blood samples to be taken from birth to ≥ 1 y of age, 32/182 provided a birth sample only, and 15/182 provided a sample later only. Nevirapine was given at delivery to 93/135 (69%) women, and to 128/135 (95%) children. Additionally, combination therapy was given to 15/135 (11%) who entered the study before delivery, and azidothymidine to their children for 1 week.

Results: Nine of 135 (6.7%) children became infected and 2/15 of the others, giving altogether 11/150 infected (7.3%). Intrauterine transmission was identified in 7/167 (4.2%) children by a positive PCR test at birth. PCR was negative at birth but positive at 1 month in 2/135 (1.5%), pointing to delivery-associated transmission. Thus, intrauterine transmission accounted for 78% (7/9). None of the uninfected children died, but 3/11 (p =0.004) of the HIV-1-infected died (in AIDS).

Conclusion: Post-test confidential counselling, formula feeding, and antiretroviral prophylaxis resulted in low rates of delivery-associated and late HIV-1 transmissions.