Association between smoking and tuberculosis infection: a population survey in a high tuberculosis incidence area.
BACKGROUND
Associations between smoking and tuberculosis disease including death from tuberculosis have been reported, but there are few reports on the influence of smoking on the risk of developing Mycobacterium tuberculosis infection. The aim of this study was to determine the association between smoking and M tuberculosis infection.


METHODS
In a cross sectional population survey, data on smoking and tuberculin skin test (TST) results of 2401 adults aged > or =15 years were compared.


RESULTS
A total of 1832 (76%) subjects had a positive TST (> or = 10 mm induration). Of 1309 current smokers or ex-smokers, 1070 (82%) had a positive TST. This was significantly higher than for never smokers (unadjusted OR 1.99, 95% confidence interval (CI) 1.62 to 2.45). A positive relationship with pack-years was observed, with those smoking more than 15 pack-years having the highest risk (adjusted OR 1.90, 95% CI 1.28 to 2.81).


CONCLUSIONS
Smoking may increase the risk of M tuberculosis infection.
Centre for TB Research and Education, Department of Paediatrics and Child Health, Stellenbosch University, P O Box 19063, 7505 Tygerberg, Cape Town, South Africa. 14321823@sun.ac.za
S
S
den Boon
S W P
SW
van Lill
M W
MW
Borgdorff
S
S
Verver
E D
ED
Bateman
C J
CJ
Lombard
D A
DA
Enarson
N
N
Beyers
D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D012959:Socioeconomic Factors; D013019:South Africa / Q000453:epidemiology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology*