Timing of mother-to-child transmission of HIV-1 and infant mortality in the first 6 months of life in Harare, Zimbabwe.
OBJECTIVE
To examine the risks of intra-uterine (IU), intra- and early post-partum (IP/ePP) and late post-partum (LPP) mother-to-child transmission (MTCT) of HIV-1 and infant mortality in the first 6 months of life.


METHODS
Whole blood was collected in ethylenediaminetetra-acetic acid at birth, 6 weeks, 3 and 6 months from 996 infants born to HIV-1 seropositive mothers. Polymerase chain reaction using Roche DNA amplification assay, version 1.5 (Roche Diagnostics Incorporation, Alameda, California, USA) 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% confidence interval (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 more than three-quarters of the 30.7% MTCT. Our data, in addition to serving as a historical comparison, may be useful in designing and evaluating the efficacy of short course antiretroviral trials aimed at reducing MTCT in developing countries.
Zijenah
Lynn S
LS
Department of Immunology, University of Zimbabwe, Harare. IZijenah@healthnet.zw
Moulton
Lawrence H
LH
Iliff
Peter
P
Nathoo
Kusum
K
Munjoma
Marshall W
MW
Mutasa
Kuda
K
Malaba
Lucie
L
Zvandasara
Parteson
P
Ward
Brian J
BJ
Humphrey
Jean
J
D000328:Adult; D004279:DNA, Viral / Q000302:isolation & purification; D005260:Female; D015658:HIV Infections / Q000401:mortality / Q000635:transmission*; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D013997:Time Factors; D015030:Zimbabwe / Q000453:epidemiology
D004279:DNA, Viral