Smoking Set to Cause 40 Million Extra Tuberculosis Deaths

From Medscape Medical News Kate Johnson October, 4, 2011 — If worldwide smoking trends continue to 2050, tuberculosis (TB) mortality rates could jump by 40 million, according to a study published online today in the British Medical Journal. "Aggressive tobacco control measures could avert millions of deaths from tuberculosis over the next four decades if these predictions are correct," write Sanjay Basu, MD, from the University of California, San Francisco, and colleagues. "In the past, multinational tobacco companies have attempted to persuade health organisations to focus on infectious diseases rather than tobacco control. Our results show that this is a false dichotomy: tobacco control is tuberculosis control," they note. Smoking increases the rate of latent TB by a factor of 1.9, active TB by 2.0, and death from TB by 2.6, after adjustment for socioeconomic status, they explain. The researchers used a mathematical model to predict the effect of various worldwide smoking scenarios on the rates of TB and death between 2010 and 2050. The model predicted that if smoking rates continue along the same trajectory as they did between 2005 and 2010, there will be a 7% increase, or 18 million excess cases of TB, by 2050 (from 256 million to 274 million) and a 66% increase, or 40 million excess deaths (from 61 million to 101 million), compared to a nonsmoking model. This would translate to a 20-year delay in meeting the Millennium Development Goal target of reducing TB mortality by half between 1990 and 2015, they reported. In a more pessimistic scenario, the model predicted that if smoking rates were to increase at twice the current rate (to a maximum of 50% prevalence), there would be a 6% increase in TB cases (reaching a total of 290 million) and a 12% increase in TB deaths (to a total of 114 million) compared to the impact of current smoking trends. If aggressive tobacco control efforts were to reduce smoking prevalence by 1% per year until eradication, the TB infection and mortality rate could be reduced by 13% and 27%, respectively, from the current trajectory, they added. The authors have disclosed no relevant financial relationships. BMJ. Published online October 4, 2011.