title: The effect of human immunodeficiency virus type-1 on the infectiousness of tuberculosis.
abstract: METHODS
  Developing country tertiary referral hospital plus catchment community.
  
  
  OBJECTIVE
  To determine the infectiousness of culture-confirmed pulmonary tuberculosis in patients infected with Human Immunodeficiency Virus type-1 (HIV-1).
  
  
  METHODS
  Comparison of the incidence of tuberculosis and the prevalence of tuberculin skin test positivity among the household contacts of both HIV-1 positive and negative cases with pulmonary tuberculosis.
  
  
  RESULTS
  Of 255 contacts of HIV-1 negative index cases, 2 were HIV-1 positive and of 102 contacts of HIV-1 positive index cases, 14 were HIV-1 positive (odds ratio (OR) = 20.0 95% Confidence Interval (CI) 4.4-193). 21 cases of tuberculosis were diagnosed among contacts, of whom 3 were HIV-1 positive. The overall unadjusted OR for tuberculosis among contacts of HIV-1 positive index cases was 1.6 (95% CI 0.6-4.3) compared to contacts of HIV-1 negative index cases. Amongst HIV-1 negative contacts alone the OR was 1.5 (95% CI 0.4-4.4). In this group the best predictors of tuberculosis among contacts were female sex of the index case (OR = 3.4 95% CI 1.1-12), sharing the same bed as the index case (OR = 2.6 95% CI 0.9-7.4), and contact's age less than 5 years (OR = 3.3 95% CI 1.1-9.5). HIV-1 positive contacts were more likely to develop tuberculosis than HIV-1 negative contacts (OR = 4.1 95% CI 0.7-17). Tuberculin skin test positivity rates were the same among the HIV-1 negative contacts of HIV-1 positive and negative index cases (OR = 1.1 CI 0.7-1.6).
  
  
  CONCLUSIONS
  HIV-1 associated pulmonary tuberculosis is not more infectious than tuberculosis alone. The presence of HIV-1 in a community does not mandate a change in the management of contacts of patients with pulmonary tuberculosis.
authors.affiliation: Kenya Medical Research Institute/Wellcome Trust Collaborative Research Programme.
authors.forename: P
authors.initials: P
authors.lastname: Nunn
authors.forename: M
authors.initials: M
authors.lastname: Mungai
authors.forename: J
authors.initials: J
authors.lastname: Nyamwaya
authors.forename: C
authors.initials: C
authors.lastname: Gicheha
authors.forename: R J
authors.initials: RJ
authors.lastname: Brindle
authors.forename: D T
authors.initials: DT
authors.lastname: Dunn
authors.forename: W
authors.initials: W
authors.lastname: Githui
authors.forename: J O
authors.initials: JO
authors.lastname: Were
authors.forename: K P
authors.initials: KP
authors.lastname: McAdam
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000635:transmission*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D003906:Developing Countries; D005192:Family Health; D005260:Female; D015497:HIV-1; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000635:transmission*