[58] TIMING OF MOTHER-TO-CHILD TRANSMISSION OF HIV-1 (MTCT) AND INFANT MORTALITY IN THE FIRST SIX MONTHS OF LIFE IN HARARE, ZIMBABWE

2nd International AIDS Society Conference on HIV Pathogenesis and Treatment

Paris, France - July 13 - 16, 2003

[TITLE:] TIMING OF MOTHER-TO-CHILD TRANSMISSION OF HIV-1 (MTCT) AND INFANT MORTALITY IN THE FIRST SIX MONTHS OF LIFE IN HARARE, ZIMBABWE

[AUTHOR(S):] LS Zijenah¹, LH Moulton², P Iliff³, K Nathoo³, MW Munjoma⁴, K Mutasa³, L Malaba⁵, P Zvandasara⁴, BJ Ward⁶ and J Humphrey^2–3 for the ZVITAMBO Study Group
¹University of Zimbabwe, Departments of Immunology; ³Paediatrics; ⁵Nutrition; ⁴Obstetrics and Gynaecology, Harare, Zimbabwe; ²Johns Hopkins Bloomberg School of Public Health; and ⁶Department of International Health, Baltimore, MD, USA and McGill University, Centre for Tropical Diseases, Quebec, Canada

IAS Conf HIV Pathog Treat 2003 Jul 13-16;2nd: Abstract No. 58
Antiviral Therapy 2003; 8(Suppl. 1):S198

[ABSTRACT:] Objective: To examine the risks of intra-uterine (IU), intra- and early post-partum (IP/ePP) and late post-partum (LPP) MTCT and infant mortality in the first 6 months of life.

Methods: Whole blood was collected in EDTA at birth, 6 weeks, 3 and 6 months from 996 infants born to HIV-1 seropositive mothers. PCR using Roche DNA amplification assay, version 1.5, was used to determine timing of MTCT. Logistic regression models determined risk factors for HIV-1 transmission and survival analyses examined mortality by timing of transmission.

Results: Two hundred and forty-nine mothers (30.7%) transmitted HIV-1 infection to their infants by 6 months of age. Eighty-nine infants (9.4%, 95% CI, 7.7–11.5), 104 infants (16.0%, 95%, CI, 10.8, 21.2) and 21 infants (5.3%, 95% CI, 1.6–12.2) were infected IU, IP/ePP and LPP respectively. Low maternal CD4+ cell count and arm circumference were risk factors for IP/ePP transmission. Infant mortality was higher among infected infants than uninfected (P<0.001, log rank test). Timing of infection, birth weight and maternal CD4+ cell counts were important factors in predicting infant death.

Conclusions: In the first 6 months of life, IU and IP/ePP transmission contributed about 25% of the 30.7% MTCT. This is the first study with a large cohort, in the absence of antiretroviral intervention, to define contributions of the three modes of MTCT. Our data, in addition to serving as a historical comparison, may be useful in the designing and evaluating the efficacy of short course antiretroviral trials aimed at reducing MTCT in developing countries.

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