title: Antenatal HIV-1 RNA load and timing of mother to child transmission; a nested case-control study in a resource poor setting.
abstract: OBJECTIVE
  To determine HIV-1 RNA load during the third trimester of pregnancy and evaluate its effect on in utero and intra-partum/postpartum transmissions in a breastfeeding population.
  
  
  METHODS
  A nested case-control study within a PMTCT cohort of antiretroviral therapy naive pregnant women and their infants.
  
  
  METHODS
  A case was a mother who transmitted HIV-1 to her infant (transmitter) who was matched to one HIV-1 positive but non-transmitting mother (control).
  
  
  RESULTS
  From a cohort of 691 pregnant women, 177 (25.6%) were HIV-1 positive at enrollment and from these 29 (23%) transmitted HIV-1 to their infants, 10 and 19 during in utero and intra-partum/postpartum respectively. Twenty-four mothers sero-converted after delivery and three transmitted HIV-1 to their infants. Each unit increase in log10 viral load was associated with a 178 cells/mm(3) and 0.2 g/dL decrease in TLC and hemoglobin levels, p = 0.048 and 0.021 respectively, and a 29% increase in the risk of transmission, p = 0.023. Intra-partum/postpartum transmitters had significantly higher mean viral load relative to their matched controls, p = 0.034.
  
  
  CONCLUSIONS
  Antenatal serum HIV-1 RNA load, TLC and hemoglobin levels were significantly associated with vertical transmission but this association was independent of transmission time. This finding supports the rationale for preventive strategies designed to reduce vertical transmission by lowering maternal viral load.
authors.affiliation: Department of Immunology, University of Zimbabwe, Harare, Zimbabwe. tkduri@yahoo.co.uk
authors.forename: Kerina
authors.initials: K
authors.lastname: Duri
authors.forename: Felicity Z
authors.initials: FZ
authors.lastname: Gumbo
authors.forename: Knut I
authors.initials: KI
authors.lastname: Kristiansen
authors.forename: Nyaradzi E
authors.initials: NE
authors.lastname: Kurewa
authors.forename: Munyaradzi P
authors.initials: MP
authors.lastname: Mapingure
authors.forename: Simbarashe
authors.initials: S
authors.lastname: Rusakaniko
authors.forename: Mike Z
authors.initials: MZ
authors.lastname: Chirenje
authors.forename: Fredrik
authors.initials: F
authors.lastname: Muller
authors.forename: Babill
authors.initials: B
authors.lastname: Stray-Pedersen
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D019829:Nevirapine / Q000627:therapeutic use; D011203:Poverty; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000821:virology*; D011296:Prenatal Diagnosis; D019562:Viral Load; D055815:Young Adult; D015030:Zimbabwe
chemical_list: D019380:Anti-HIV Agents; D019829:Nevirapine