Predictors of early and late mother-to-child transmission of HIV in a breastfeeding population: HIV Network for Prevention Trials 012 experience, Kampala, Uganda.
OBJECTIVE
To determine the predictors for early versus later (breastfeeding) transmission of HIV-1.


METHODS
Secondary data analysis was performed on HIV Network for Prevention Trials 012, a completed randomized clinical trial assessing the relative efficacy of nevirapine (NVP) versus zidovudine in reducing mother-to-child transmission (MTCT) of HIV-1. We used Cox regression analysis to assess risk factors for MTCT. The ViroSeq HIV genotyping and a sensitive point mutation assay were used to detect NVP resistance mutations.


RESULTS
In this subset analyses, 122 of 610 infants were HIV infected, of whom 99 (81.1%) were infected early (first positive polymerase chain reaction < or =56 days). Incidence of MTCT after 56 days was low [0.7% per month (95% confidence interval, CI: 0.4 to 1.0)], but continued through 18 months. In multivariate analyses, early MTCT "factors" included NVP versus zidovudine (hazard ratio (HR) = 0.57, 95% CI: 0.38 to 0.86), pre-entry maternal viral load (VL, HR = 1.76, 95% CI: 1.28 to 2.41), and CD4 cell count (HR = 1.16, 95% CI: 1.05 to 1.28). Maternal VL (6-8 weeks) was associated with late MTCT (HR = 3.66, 95% CI: 1.78 to 7.50), whereas maternal NVP resistance (6-8 weeks) was not.


CONCLUSIONS
Maternal VL was the best predictor of both early and late transmission. Maternal NVP resistance at 6-8 weeks did not predict late transmission.
Mmiro
Francis A
FA
Makerere University-Johns Hopkins University Research Collaboration, Kampala, Uganda.
Aizire
Jim
J
Mwatha
Anthony K
AK
Eshleman
Susan H
SH
Donnell
Deborah
D
Fowler
Mary Glenn
MG
Nakabiito
Clemensia
C
Musoke
Philippa M
PM
Jackson
J Brooks
JB
Guay
Laura A
LA
D019380:Anti-HIV Agents / Q000627:therapeutic use; D001942:Breast Feeding; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D015999:Multivariate Analysis; D019829:Nevirapine / Q000627:therapeutic use; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D016016:Proportional Hazards Models; D014454:Uganda / Q000453:epidemiology; D019562:Viral Load; D015215:Zidovudine / Q000627:therapeutic use
D019380:Anti-HIV Agents; D015215:Zidovudine; D019829:Nevirapine