Tuberculosis (TB) and Tobacco Smoking

What is the connection between TB and tobacco smoking?

There is a strong association between smoking tobacco and TB.  Cigarette smoking can affect how someone becomes infected with the TB bacteria and how the infection progresses to active TB disease in three main ways:

• smoking damages the lungs and can make smokers more susceptible to TB infection;
• smoking harms the body's immune system, meaning smokers are less able to combat TB infection; and
• smoking reduces the effectiveness of TB treatment which can lead to longer periods of infection and/or more severe forms of the disease.

Does smoking increase the risk of becoming infected with the TB bacteria in the first place?

Yes. If cigarette smokers breathe in TB bacteria, they may be up to three times more likely to develop latent TB infection than non-smokers.  The risk of infection also increases the more you smoke and the longer you have been smoking.

Does smoking increase the risk of developing active TB disease?

For a person with latent TB infection, cigarette smoking increases their risk of developing active TB disease by two to three times, compared to non-smokers.  Smoking also increases the risk of death among TB patients up to six times.

Even if you have been cured in the past, the risk of developing active TB disease again is three times higher in cigarette smokers compared to non-smokers. 

What should I do if I have latent TB infection and I smoke?

Quitting smoking is one of the best ways you can protect yourself from developing active TB disease.  Quitting smoking will not only decrease your risk of developing TB disease, but it will also help your treatment for latent TB infection.

If you are looking for counselling to help you stop smoking, your physician is the best professional to seek advice from.  He or she can help you find a program or treatment that can help you quit.

What should I do if I have TB disease and I smoke?

Smoking is associated with more severe disease and an increased death rate so quitting is the best action you can take when you are diagnosed with TB.  In fact, up to one in every five deaths from TB could be avoided if the individuals did not smoke.
 
After you quit, most immune system problems caused by smoking can be reversed.

Speak to your physician about cessation counselling and how you can quit.

Does exposure to second-hand smoke increase the risk of becoming infected with TB bacteria in the first place?

Exposure to second-hand smoke increases the risks of both TB infection and development of active TB disease among children and adults.  For children and young adults, the more second-hand smoke they are exposed to, the higher the risk of developing TB.

In addition to endangering their own health, TB patients who smoke in the home are also placing their families at a greater risk of TB infection.  It is very important to keep your home smoke-free.