title: Timing of mother-to-child transmission of HIV-1 and infant mortality in the first 6 months of life in Harare, Zimbabwe.
abstract: 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.
authors.affiliation: Department of Immunology, University of Zimbabwe, Harare. IZijenah@healthnet.zw
authors.forename: Lynn S
authors.initials: LS
authors.lastname: Zijenah
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Moulton
authors.forename: Peter
authors.initials: P
authors.lastname: Iliff
authors.forename: Kusum
authors.initials: K
authors.lastname: Nathoo
authors.forename: Marshall W
authors.initials: MW
authors.lastname: Munjoma
authors.forename: Kuda
authors.initials: K
authors.lastname: Mutasa
authors.forename: Lucie
authors.initials: L
authors.lastname: Malaba
authors.forename: Parteson
authors.initials: P
authors.lastname: Zvandasara
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Ward
authors.forename: Jean
authors.initials: J
authors.lastname: Humphrey
mesh_terms: 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
chemical_list: D004279:DNA, Viral