title: HIV viraemia and mother-to-child transmission risk after antiretroviral therapy initiation in pregnancy in Cape Town, South Africa.
abstract: Maternal HIV viral load (VL) drives mother-to-child HIV transmission (MTCT) risk but there are few data from sub-Saharan Africa, where most MTCT occurs. We investigated VL changes during pregnancy and MTCT following antiretroviral therapy (ART) initiation in Cape Town, South Africa.
  
  
  
  We conducted a prospective study of HIV-infected women initiating ART within routine antenatal services in a primary care setting. VL measurements were taken before ART initiation and up to three more times within 7 days postpartum. Analyses examined VL changes over time, viral suppression (VS) at delivery, and early MTCT based on polymerase chain reaction (PCR) testing up to 8 weeks of age.
  
  
  
  A total of 620 ART-eligible HIV-infected pregnant women initiated ART, with 2425 VL measurements by delivery (median gestation at initiation, 20 weeks; median pre-ART VL, 4.0 log10HIV-1 RNA copies/mL; median time on ART before delivery, 118 days). At delivery, 91% and 73% of women had VL ≤ 1000 and ≤ 50 copies/mL, respectively. VS was strongly predicted by time on therapy and pre-ART VL. The risk of early MTCT was strongly associated with delivery VL, with risks of 0.25, 2.0 and 8.5% among women with VL < 50, 50-1000 and > 1000 copies/mL at delivery, respectively (P < 0.001).
  
  
  
  High rates of VS at delivery and low rates of MTCT can be achieved in a routine care setting in sub-Saharan Africa, indicating the effectiveness of currently recommended ART regimens. Women initiating ART late in pregnancy and with high VL appear substantially less likely to achieve VS and require targeted research and programmatic attention.
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: Myer
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: T K
authors.initials: TK
authors.lastname: Phillips
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa.|Anova Health Institute, Johannesburg, South Africa.
authors.forename: J A
authors.initials: JA
authors.lastname: McIntyre
authors.affiliation: Division of Medical Virology, University of Cape Town & National Health Laboratory Services, Cape Town, South Africa.
authors.forename: N-Y
authors.initials: NY
authors.lastname: Hsiao
authors.affiliation: Department of Obstetrics & Gynaecology, University of Cape Town, Cape Town, South Africa.
authors.forename: G
authors.initials: G
authors.lastname: Petro
authors.affiliation: ICAP, Columbia University Mailman School of Public Health, New York, NY, USA.
authors.forename: A
authors.initials: A
authors.lastname: Zerbe
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: J
authors.initials: J
authors.lastname: Ramjith
authors.affiliation: Desmond Tutu HIV Centre, Institute of Infectious Diseases & Molecular Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: L-G
authors.initials: LG
authors.lastname: Bekker
authors.affiliation: ICAP, Columbia University Mailman School of Public Health, New York, NY, USA.|College of Physicians & Surgeons, Columbia University, New York, NY, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Abrams
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D008137:Longitudinal Studies; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy* / Q000821:virology*; D011446:Prospective Studies; D018570:Risk Assessment; D013019:South Africa; D019562:Viral Load; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents
keywords: 
  HIV
  ; antiretroviral therapy; mother-to-child transmission; pregnancy; viral load.