Tuberculosis transmission attributable to close contacts and HIV status, Malawi.
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.
Crampin
Amelia C
AC
London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom.
Glynn
Judith R
JR
Traore
Hamidou
H
Yates
Malcolm D
MD
Mwaungulu
Lorren
L
Mwenebabu
Michael
M
Chaguluka
Steven D
SD
Floyd
Sian
S
Drobniewski
Francis
F
Fine
Paul E M
PE
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*