title: Tuberculosis transmission attributable to close contacts and HIV status, Malawi.
abstract: We conducted the first molecular study of tuberculosis (TB) to estimate the role of household contact and transmission from HIV-positive putative source contacts (PSCs) in a high HIV-prevalence area. TB patients in a long-term population-based study in Malawi were asked about past contact with TB. DNA fingerprinting was used to define clusters of cases with identical strains. Among 143 epidemiologically defined PSC-case pairs, fingerprinting confirmed transmission for 44% of household and family contacts and 18% of other contacts. Transmission was less likely to be confirmed if the PSC were HIV positive than if he or she was HIV negative (odds ratio 0.32, 95% confidence interval [CI] 0.14-0.74). Overall, epidemiologic links were found for 11% of 754 fingerprint-clustered cases. We estimate that 9%-13% of TB cases were attributable to recent transmission from identifiable close contacts and that nearly half of the TB cases arising from recent infection had acquired the infection from HIV-positive patients.
authors.affiliation: London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom.
authors.forename: Amelia C
authors.initials: AC
authors.lastname: Crampin
authors.forename: Judith R
authors.initials: JR
authors.lastname: Glynn
authors.forename: Hamidou
authors.initials: H
authors.lastname: Traore
authors.forename: Malcolm D
authors.initials: MD
authors.lastname: Yates
authors.forename: Lorren
authors.initials: L
authors.lastname: Mwaungulu
authors.forename: Michael
authors.initials: M
authors.lastname: Mwenebabu
authors.forename: Steven D
authors.initials: SD
authors.lastname: Chaguluka
authors.forename: Sian
authors.initials: S
authors.lastname: Floyd
authors.forename: Francis
authors.initials: F
authors.lastname: Drobniewski
authors.forename: Paul E M
authors.initials: PE
authors.lastname: Fine
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000635:transmission*; D000328:Adult; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology; D006679:HIV Seropositivity; D006801:Humans; D008295:Malawi / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D012307:Risk Factors; D014376:Tuberculosis / Q000453:epidemiology* / Q000635:transmission*