Association between smoking and tuberculosis infection: a population survey in a high tuberculosis incidence area
- S den Boon1,2,
- S W P van Lill1,
- M W Borgdorff2,3,
- S Verver3,
- E D Bateman4,
- C J Lombard5,
- D A Enarson6,
- N Beyers1
- 1Centre for TB Research and Education, Department of Paediatrics and Child Health, Stellenbosch University, P O Box 19063, 7505 Tygerberg, Cape Town, South Africa
- 2Academic Medical Centre, Amsterdam, The Netherlands
- 3KNCV Tuberculosis Foundation, The Hague, The Netherlands
- 4Division of Pulmonology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- 5Biostatistics Unit, Medical Research Council, Cape Town, South Africa
- 6International Union Against Tuberculosis and Lung Diseases, Paris, France
- Correspondence to:
MsS den Boon
Centre for TB Research and Education, Department of Paediatrics and Child Health, Stellenbosch University, P O Box 19063, 7505 Tygerberg, Cape Town, South Africa;
- Received 5 July 2004
- Accepted 6 April 2005
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 ⩾15 years were compared.
Results: A total of 1832 (76%) subjects had a positive TST (⩾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).
Conclusion: Smoking may increase the risk of M tuberculosis infection.
NB, EB, SvL, DE, and MB were involved in the study design and writing of the manuscript. SdB performed the statistical analysis and wrote the paper. Advice on statistics was given by CL, SV and MB. All authors participated in interpretation of the results. NB supervised the data collection and MB the statistical analyses.
This study was funded by Stellenbosch University through funding from the South African Department of Trade and Industry (THRIP fund) and the Glaxo Smith Kline Action TB Programme, and the University of Cape Town Lung Institute. MWB and SV were supported by Areas Global TB Vaccine Foundation. None of the funding sources had any role in the study design; the collection, analyses, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.