Smoking-related TB could rise if worldwide smoking rates continue

If smoking rates stay at current levels, smoking could create 18 million extra cases of tuberculosis worldwide and 40 million excess deaths from the disease by 2050, a study finds.

Researchers produced mathematical models based on various smoking rate scenarios to estimate rates of tuberculosis disease and deaths in each World Health Organization region around the world. The baseline scenario used current smoking levels to come up with the 18 million and 40 million numbers; right now, almost 20% of people worldwide smoke tobacco, and that figure may rise in some poor countries, the study authors said.

Here's how bad it could get: In a "pessimistic" scenario, researchers projected numbers based on smoking prevalence growing at two times the current rate, until half of all people smoked. That would mean an added 34 million tuberculosis cases attributed to smoking and an excess 114 million deaths from smoking-related tuberculosis from 2010 to 2050.

And what if smoking frequency were cut by 1% each year from 2015 until it was gone? That would mean a drop of 13% in cumulative smoking-related TB cases and 27% in cumulative smoking-related deaths from TB by 2050, compared with the baseline numbers.

Studies have shown a link between smoking and a greater risk of contracting tuberculosis. Health experts believe that smoking might make the lungs less capable of fighting infections by altering cells that would normally be able to battle pathogens.

"The tobacco industry has spent decades working to convince developing countries as well as funding agencies that they should not 'waste' their time on tobacco control," said lead author Dr. Sanjay Basu of UC San Francisco in a news release, "but rather focus on infectious diseases like tuberculosis at the same time that the multinational tobacco companies were expanding aggressively in those very countries."