title: Plasma viraemia in HIV-positive pregnant women entering antenatal care in South Africa.
abstract: BACKGROUND
  Plasma HIV viral load (VL) is the principle determinant of mother-to-child HIV transmission (MTCT), yet there are few data on VL in populations of pregnant women in sub-Saharan Africa. We examined the distribution and determinants of VL in HIV-positive women seeking antenatal care (ANC) in Cape Town, South Africa.
  
  
  METHODS
  Consecutive HIV-positive pregnant women making their first antenatal clinic visit were recruited into a cross-sectional study of viraemia in pregnancy, including a brief questionnaire and specimens for VL testing and CD4 cell enumeration.
  
  
  CONCLUSIONS
  Overall 5551 pregnant women sought ANC during the study period, of whom 1839 (33%) were HIV positive and 1521 (85%) were included. Approximately two-thirds of HIV-positive women in the sample (n=947) were not on antiretrovirals at the time of the first ANC visit, and the remainder (38%, n=574) had initiated antiretroviral therapy (ART) prior to conception. For women not on ART, the median VL was 3.98 log10 copies/mL; in this group, the sensitivity of CD4 cell counts ≤350 cells/µL in detecting VL>10,000 copies/mL was 64% and this increased to 78% with a CD4 threshold of ≤500 cells/µL. Among women on ART, 78% had VL<50 copies/mL and 13% had VL >1000 copies/mL at the time of their ANC visit.
  
  
  CONCLUSIONS
  VL >10,000 copies/mL was commonly observed in women not on ART with CD4 cell counts >350 cells/µL, suggesting that CD4 cell counts may not be adequately sensitive in identifying women at greatest risk of MTCT. A large proportion of women entering ANC initiated ART before conception, and in this group more than 10% had VL>1000 copies/mL despite ART use. VL monitoring during pregnancy may help to identify pregnancies that require additional clinical attention to minimize MTCT risk and improve maternal and child health outcomes.
authors.affiliation: Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa; landon.myer@uct.ac.za.
authors.forename: Landon
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: Tamsin K
authors.initials: TK
authors.lastname: Phillips
authors.affiliation: Division of Medical Virology, University of Cape Town, South Africa.|National Health Laboratory Services, Cape Town, South Africa.
authors.forename: Nei-Yuan
authors.initials: NY
authors.lastname: Hsiao
authors.affiliation: ICAP, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Zerbe
authors.affiliation: Department of Obstetrics & Gynaecology, University of Cape Town, Cape Town, South Africa.
authors.forename: Gregory
authors.initials: G
authors.lastname: Petro
authors.affiliation: Desmond Tutu HIV Centre, Institute of Infectious Diseases & Molecular Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Linda-Gail
authors.initials: LG
authors.lastname: Bekker
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: James A
authors.initials: JA
authors.lastname: McIntyre
authors.affiliation: ICAP, Mailman School of Public Health, Columbia University, New York, NY, USA.|College of Physicians & Surgeons, Columbia University, New York, NY, USA.
authors.forename: Elaine J
authors.initials: EJ
authors.lastname: Abrams
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000517:prevention & control; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*; D011295:Prenatal Care; D013019:South Africa; D014766:Viremia / Q000188:drug therapy*
chemical_list: D019380:Anti-HIV Agents
keywords: South Africa; antiretroviral therapy; pregnancy; prevention of mother-to-child transmission; viral load