title: Tuberculosis during the first year of antiretroviral therapy in a South African cohort using an intensive pretreatment screening strategy.
abstract: OBJECTIVE
  To determine the baseline prevalence of tuberculosis (TB) in a cohort using a strategy of intensive pretreatment screening for TB and the subsequent incidence rate and temporal distribution of cases during the first year of antiretroviral therapy (ART).
  
  
  METHODS
  Prospective observational community-based ART cohort in South Africa.
  
  
  METHODS
  Adults enrolling for ART and who did not have a current TB diagnosis were intensively screened for TB at baseline using culture of two sputum samples, chest radiography and investigations for extrapulmonary disease as required. Patients who developed symptoms consistent with incident TB during ART were similarly investigated.
  
  
  RESULTS
  Two hundred forty-one patients had a median CD4 cell count of 125 cells/microl (interquartile range 70-186) and 200 (83%) started ART. TB was diagnosed in 87 (36%) patients, with 82% of pulmonary cases being culture-proven. Most TB cases (87%) were prevalent disease detectable at baseline, whereas just 11 (13%) were incident cases that presented during the first year of ART. The incidence rate during 0-4 months of ART was similar to the rate during months 5-12 of ART [10.9 (95% confidence interval [CI] 4.6-23.3) cases per 100 person-years versus 8.1 (95% CI 3.6-18.0) cases per 100 person-years].
  
  
  CONCLUSIONS
  Systematic culture-based screening detected a very high burden of prevalent TB present at baseline. This intensified screening strategy was associated with an approximately two-fold lower incidence rate in the first 4 months of ART than previously observed in this cohort. This suggests that many incident cases of symptomatic TB presenting during early ART can be detected as prevalent disease prior to ART initiation using sensitive diagnostic tests.
authors.affiliation: The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, University of Cape Town, South Africa. stevelawn@yahoo.co.uk <stevelawn@yahoo.co.uk>
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Lawn
authors.forename: Katharina
authors.initials: K
authors.lastname: Kranzer
authors.forename: David J
authors.initials: DJ
authors.lastname: Edwards
authors.forename: Matthew
authors.initials: M
authors.lastname: McNally
authors.forename: Linda-Gail
authors.initials: LG
authors.lastname: Bekker
authors.forename: Robin
authors.initials: R
authors.lastname: Wood
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D000995:Antitubercular Agents / Q000008:administration & dosage; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology; D015497:HIV-1; D006801:Humans; D008297:Male; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013019:South Africa / Q000453:epidemiology; D013183:Sputum / Q000821:virology; D011795:Surveys and Questionnaires; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D019380:Anti-HIV Agents; D000995:Antitubercular Agents
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