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  5th IAS Conference on HIV Pathogenesis, Treatment and Prevention
July 19th-22nd 2009
Capetown, South Africa
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Triple Antiretrovirals Cut Breastfeeding HIV Transmission Rate Below 1%
  5th IAS Conference on HIV Pathogenesis, Treatment and Prevention, July 19-22, 2009, Cape Town
Mark Mascolini
Standard triple antiretroviral combinations, one of them already widely used in low-income countries, sliced HIV transmission rates during breastfeeding to less than 1%--the lowest rate ever recorded among breastfeeding women with HIV [1]. The overall transmission rate during gestation, delivery, and breastfeeding in this large Botswana trial came to 1%. The results argue strongly that routine antiretroviral therapy should be the standard of care for pregnant and breastfeeding women with HIV.
The Mma Bana Study is the first randomized trial of triple antiretroviral regimens to control viral replication in mothers and to prevent mother-to-child transmission of HIV in utero, during delivery, and during breastfeeding. The study involved 730 women, 560 with a CD4 count above 199 and 170 with fewer CD4 cells. The women with CD4 counts under 200 started nevirapine plus coformulated zidovudine/lamivudine, as recommended in Botswana's national guidelines. Women with higher CD4 counts were randomized to coformulated abacavir, zidovudine, and lamivudine or to lopinavir/ritonavir plus coformulated zidovudine/lamivudine.
Women began treatment between gestation weeks 26 and 34 and aimed to continue through 6 months after delivery. They were strongly encouraged to wean their infants by 6 months. Researchers tested infants for HIV with DNA PCR at birth and at 1, 3, and 6 months of age. In the women, median pretreatment viral loads were 13,300 copies in the abacavir group, 9100 copies in the lopinavir group, and 51,700 copies in the nevirapine group.
At delivery more than 90% of women in all three study groups had a viral load below 400 copies--96% in the abacavir group, 93% in the lopinavir group, and 94% in the observational nevirapine group. During breastfeeding, 92%, 93%, and 95% in those three groups maintained a load below 400 copies.
Five women taking coformulated abacavir/zidovudine/lamivudine transmitted HIV to their infants, 3 in utero and 2 while breastfeeding. One woman in each of the other two groups transmitted HIV, both in utero. Overall transmission rates were 1.8% with abacavir, 0.4% with lopinavir (P = 0.53 versus abacavir), and 0.6% with nevirapine. Overall transmission through 6 months was 1% (95% confidence interval 0.5% to 2.0%).
There were 11 stillbirths with abacavir (3%), 5 with lopinavir (2%), and 11 (7%) with nevirapine (P = 0.07 for abacavir and lopinavir versus nevirapine). Premature delivery (before 37 weeks) occurred in 42 women taking abacavir (15%), 61 taking lopinavir (23%, P = 0. 04 versus abacavir), and 16 (10%) taking nevirapine. Low birth weight (below 2.5 kg) was recorded in 37 infants of mothers taking abacavir (13%), 45 infants of mothers taking lopinavir (17%), and 23 infants of mothers taking nevirapine (15%). Congenital abnormalities affected 5 infants in each treatment group.
Grade 3 to 4 adverse events affected 17 women taking abacavir (6%), 16 taking lopinavir (6%), and 25 taking nevirapine (16%). The higher rate with nevirapine at least partly reflects the more advanced HIV infection in these women when they began therapy.
Similar results in other studies reported at this meeting may impel the World Health Organization to recommend triple antiretroviral therapy for all HIV-infected women during pregnancy, delivery, and breastfeeding, according to Reuters [2].
1. Shapiro R, Hughes M,. Ogwu A, et al. 5th IAS Conference on HIV Pathogenesis, Treatment and Prevention. July 19-22, 2009. Cape Town. Abstract WELBB101.
2. Reuters. WHO may change ARV guidelines for pregnant mothers. July 22, 2009.