title: Late postnatal transmission of HIV-1 in breast-fed children: an individual patient data meta-analysis.
abstract: BACKGROUND
  We analyzed individual patient data to determine the contribution of late postnatal transmission to the overall risk of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) and the timing and determinants of late postnatal transmission.
  
  
  METHODS
  Eligible trials were conducted where breast-feeding was common; included >/=2 HIV-1 tests by 3 months, and, if follow-up continued, >/=2 tests at 3-12 months; and regularly assessed infant-feeding modality. Data on children born before January 2000 were analyzed.
  
  
  RESULTS
  Of 4085 children from 9 trials (breast-fed singletons for whom HIV-1 testing was performed), 993 (24%) were definitively infected (placebo arms, 25.9%; treatment arms, 23.4%; P=.08). Of 539 children with known timing of infection, 225 (42%) had late postnatal transmission. Late postnatal transmission occurred throughout breast-feeding. The estimated hazard function for time to late postnatal transmission was roughly constant. The cumulative probability of late postnatal transmission at 18 months was 9.3%. The overall risk of late postnatal transmission was 8.9 transmissions/100 child-years of breast-feeding and was significantly higher with lower maternal CD4(+) cell counts and male sex.
  
  
  CONCLUSIONS
  Late postnatal transmission contributes substantially to overall mother-to-child transmission of HIV-1. The risk of late postnatal transmission is generally constant throughout breast-feeding, and late postnatal transmission is associated with a lower maternal CD4(+) cell count and male sex. Biological and cultural mechanisms underlying the association between sex and late postnatal transmission should be further investigated. Interventions to decrease transmission of HIV-1 through breast-feeding are urgently needed.
authors.forename: Anna
authors.initials: A
authors.lastname: Coutsoudis
authors.forename: Francois
authors.initials: F
authors.lastname: Dabis
authors.forename: Wafaie
authors.initials: W
authors.lastname: Fawzi
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaillard
authors.forename: Geert
authors.initials: G
authors.lastname: Haverkamp
authors.forename: D Robert
authors.initials: DR
authors.lastname: Harris
authors.forename: J Brooks
authors.initials: JB
authors.lastname: Jackson
authors.forename: Valerie
authors.initials: V
authors.lastname: Leroy
authors.forename: Nicolas
authors.initials: N
authors.lastname: Meda
authors.forename: Philippe
authors.initials: P
authors.lastname: Msellati
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Newell
authors.forename: Ruth
authors.initials: R
authors.lastname: Nsuati
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Read
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiktor
mesh_terms: D001942:Breast Feeding / Q000009:adverse effects*; D005260:Female; D015658:HIV Infections / Q000635:transmission* / Q000821:virology; D015497:HIV-1; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008895:Milk, Human / Q000821:virology*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013997:Time Factors