Smoking is an independent risk factor for both quiescent TB infection and the development of active TB, according to a new systematic review and meta-analysis.
To quantify the relationship between smoking and TB, pulmonary disease, and mortality, researchers at the University of California, Berkeley, analyzed data from 24 published studies. They found that smokers have a 73% greater chance of becoming infected with Mycobacterium tuberculosis than nonsmokers. For people infected with TB, the chances of developing active disease are about 50% greater in smokers than in nonsmokers. Extrapolating from the data, the researchers said that smoking may be responsible for more than 30% of TB cases and deaths.
However, they add that it is not clear at this point whether smoking further increases the risk of death in people who already have TB.
Because smoking is potentially one of the most modifiable risk factors for TB, the authors concluded that “smoking prevention and cessation efforts should be a priority in any TB prevention program” (Arch Intern Med. 2007; 167:335-342).