title: Community viral load and CD4 count distribution among people living with HIV in a South African Township: implications for treatment as prevention.
abstract: BACKGROUND
  The goals of scale-up of antiretroviral therapy (ART) have expanded from prevention of morbidity and death to include prevention of transmission. Morbidity and mortality risk are associated with CD4 count; transmission risk depends on plasma viral load (VL). This study aimed to describe CD4 count and VL distributions among HIV-infected individuals in a South African township to gain insights into the potential impact of ART scale-up on community HIV transmission risk.
  
  
  METHODS
  A random sample of 10% of the adult population was invited to attend an HIV testing service. Study procedures included a questionnaire, HIV testing, CD4 count, and VL testing.
  
  
  RESULTS
  One thousand one hundred forty-four (88.0%) of 1300 randomly selected individuals participated in the study. Two hundred sixty tested positive, giving an HIV prevalence of 22.7% [95% confidence interval (CI): 20.3 to 25.3]. A third of all HIV-infected individuals (33.5%, 95% CI: 27.8 to 39.6) reported taking ART. The median CD4 count was 417 cells per microliter (interquartile range, 285-627); 33 (12.7%, 95% CI: 8.9 to 17.4) had a CD4 count of ≤200 cells per microliter. VL measurements were available for 219 individuals (84.2%) and were undetectable in 72 (33.9%), >1500 copies per milliliter in 127 (58.0%) and >10,000 copies per milliliter in 96 (43.8%). Of those reporting they were receiving ART, 30.4% had a VL >1500 copies per milliliter compared with 58.0% of those reporting they were not receiving ART.
  
  
  CONCLUSIONS
  A small proportion of those living with HIV in this community had a CD4 count of <200 cells per microliter; more than half had a VL high enough to be associated with considerable transmission risk. A substantial proportion of HIV-infected individuals remained at risk of transmitting HIV even after starting ART.
authors.affiliation: Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. katharina.kranzer@lshtm.ac.uk
authors.forename: Katharina
authors.initials: K
authors.lastname: Kranzer
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Lawn
authors.forename: Leigh F
authors.initials: LF
authors.lastname: Johnson
authors.forename: Linda-Gail
authors.initials: LG
authors.lastname: Bekker
authors.forename: Robin
authors.initials: R
authors.lastname: Wood
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000635:transmission* / Q000821:virology; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D018570:Risk Assessment; D012307:Risk Factors; D013019:South Africa; D011795:Surveys and Questionnaires; D019562:Viral Load; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents