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15th Conference on Retroviruses and Opportunistic InfectionsBoston, Massachusetts - February 3-6, 2008 |
Conf Retrovir Opportunistic Infect 2008 Feb 3-6;15: (abstract no. 45aLB)
Timothy Thomas
1, R Masaba2, R Ndivo2, C Zeh1, C Borkowf3, M Thigpen3, K De Cock1, P Amornkul1, A Greenberg3, M Fowler3, and Kisumu Breastfeeding Study Team
1CDC kenya, Kisumu; 2Kenya Med Res Inst, Kisumu; and 3CDC, Atlanta, GA USA
BACKGROUND: Several trials are underway to assess use of extended maternal or infant antiretrovirals (ARV) to reduce mother-to-child transmission (MTCT) among HIV-exposed breastfed infants where infection rates of 25 to 48% have been observed. We assessed transmission rates in the Kisumu Breastfeeding Study (KiBS), a phase IIb single-arm prevention of (PMTCT) trial using zidovudine/lamivudine and nevirapine (NVP) (later modified to nelfinavir (NLF) for those women with CD4 >250 cells/µL) from 34 weeks; gestation to 6 months’ postpartum. Infants received single-dose NVP at birth. Women were advised to exclusively breastfeed and wean rapidly at 6 months.
METHODS: We tested infant dried blood spots collected at delivery, 2, 6, and 14 weeks and 6, 9, and 12 months using polymerase chain reaction (PCR). Kaplan-Meier methods were used to estimate rates of HIV infection overall, by maternal enrolment CD4 count (≤ or >250 cells/µL) and by initial regimen (NVP or NLF) for those with maternal CD4 >250 cells/µL.
RESULTS: HIV infection data were available for 497 infants born alive: 27(11 males, 16 females) became infected, 3 after 6 months. Cumulative infant HIV infection rates per 100 infants (95%CI) and by maternal CD4 count and regimen are shown in the table. The log-rank test showed no difference in infection rates by maternal CD4 (p=0.89) or by regimen (p=083). The overall rate at 12 months for females was 7.4 (95%CI 4.6 to 11.9), males 4.5 (95%CI 2.5 to 8.1)(p=0.15).
| Age | 0-7 days | 6 weeks | 3 months | 6 months | 12 months |
| Transmission events | 12 | 19 | 20 | 24 | 27 |
| All infants (n=497) | 2.4 (1.4-4.2) | 3.9 (2.5-6.0) | 4.1 (2.7-6.3) | 5.0 (3.4-7.3) | 5.9 (4.0-8.5) |
| CD4 ≤250 (n=118) | 3.4 (1.3-8.8) | 4.3 (1.8-10.0) | 5.2 (2.4-11.2) | 5.2 (2.4-11.2) | 6.7 (3.2-13.9) |
| CD4 >250 (n=379) | 2.1 (1.1-4.2) | 3.8 (2.2-6.3) | 3.8 (2.2-6.3) | 4.9 (3.1-7.7) | 5.5 (3.6-8.4) |
| Nevirapine (n=178) | 1.1 (0.3-4.4) | 3.4 (1.6-7.5) | 3.4 (1.6-7.5) | 5.2 (2.8-9.8) | 5.9 (3.2-10.6) |
| Nelfinavir (n=201) | 3.0 (1.4-6.5) | 4.0 (2.0-7.9) | 4.0 (2.0-7.9) | 4.6 (2.4-8.6) | 5.2 (2.8-9.5) |
CONCLUSIONS: Low 12-month infant HIV transmission rates were achieved using maternal HAART from late pregnancy through 6 months of breastfeeding. There was no difference in transmission based on maternal CD4 or regimen. Further assessment–adherence to antiretrovirals, the optimal timing for breastfeeding cessation, HIV-free survival, and drug resistance in maternal and infant HIV isolates–is necessary to determine whether HAART is a feasible, acceptable, safe, and efficacious strategy for PMTCT among breastfeeding women, particularly those not meeting WHO treatment criteria.
2008-02-03
45aLB
Copyright © 2008 - Foundation for Retrovirology and Human Health. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Foundation for Retrovirology and Human Health.
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