title: Chronic airflow obstruction and respiratory symptoms following tuberculosis: a review of South African studies.
abstract: BACKGROUND
  There is renewed interest in the chronic respiratory sequelae of pulmonary tuberculosis (PTB), particularly chronic airflow limitation. A number of South African epidemiological studies have been published, which, although not specifically designed to examine this association, provide useful data on the nature of the relationship.
  
  
  OBJECTIVE
  To review population-based and occupational studies conducted in South Africa that provide estimates of the association between PTB, chronic symptoms and lung function loss.
  
  
  RESULTS
  Two general population and a number of occupational studies were included. Most were able to control for likely confounders. Chronic chest symptoms and lung function loss were consistently associated with PTB, whether measured by self-report or prospectively in cohort studies. Odds ratios (ORs) were higher for chronic bronchitis (range 1.5-7.2) than for asthma (range 0.7-2.2). For spirometrically defined chronic obstructive pulmonary disease, the OR range was 2.6-8.9, depending on definition. Combined obstructive/restrictive lung function loss was the most common functional outcome, with a net obstructive effect. The association of past TB with non-specific bronchial hyperresponsiveness was equivocal.
  
  
  CONCLUSIONS
  These studies add to the evidence of a strong association between PTB, even if treated, and subsequent airflow obstruction as well as restrictive loss. Unanswered questions include extent of recovery over time, effect modification by smoking and other cofactors, and degree of reversibility by treatment.
authors.affiliation: Centre for Occupational and Environmental Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa. Rodney.ehrlich@uct.ac.za
authors.forename: R I
authors.initials: RI
authors.lastname: Ehrlich
authors.forename: S
authors.initials: S
authors.lastname: Adams
authors.forename: R
authors.initials: R
authors.lastname: Baatjies
authors.forename: M F
authors.initials: MF
authors.lastname: Jeebhay
mesh_terms: D000402:Airway Obstruction / Q000453:epidemiology / Q000209:etiology*; D016535:Bronchial Hyperreactivity / Q000453:epidemiology / Q000209:etiology; D002908:Chronic Disease; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000209:etiology*; D012129:Respiratory Function Tests; D013019:South Africa / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000150:complications*