The harmful synergy between smoking and tuberculosis disproportionately affects those living in LMICs
Today, 24 March, is World Tuberculosis (TB) Day. In 2020, TB was the second leading infectious killer after Covid-19 (above HIV/AIDS), infecting 10 million people worldwide. As with smoking, the harms caused by TB are exacerbating pre-existing health and economic inequalities; over 95% of cases and deaths are in low- and middle-income countries (LMICs).
Understandably, global attention and budgets have been focused on communicable disease in the past two years during the Covid-19 pandemic. But it is impossible to ignore the tremendously harmful synergy between non-communicable disease and infectious disease. For example, obesity is associated with four times the risk of Covid-19 infection, and two times the risk of death. Similarly, TB is the third leading cause of death amongst people with non-communicable disease, particularly diabetes mellitus (DM). In fact, the number of people living with TB-DM comorbidity has now far surpassed the number of people living with TB-HIV comorbidity.
Tobacco smoking has been suspected as a risk factor for TB for more than a century. Now, the epidemiological evidence is unequivocal. Here are 5 facts that prove how dangerous the combination of smoking and TB is:
- Smoking more than 20 cigarettes per day increases your odds of contracting TB by 4.5 times
- In TB-endemic countries such as South Africa, at least 60% of people with active and latent TB are smokers
- Diabetic patients who smoke are 6 times more likely to contract TB than non-smokers
- Smoking is a major barrier towards TB treatment success: treatment is 24% less effective in smokers
- Children exposed to second-hand smoke are two times more likely to be exposed to tuberculous infection and TB disease
Complex problems require multi-faceted solutions
The harmful synergy between TB and non-communicable disease (most notably, diabetes mellitus and smoking) is a complex health challenge that will require not only significant funding, but also well thought-through, holistic solutions. Recently, there was an 8.7% decline in global spending on tackling the TB epidemic, despite it already being less than half of the global target. Ultimately, people living in LMICs will suffer the consequences of this trend, which does not bode well for meeting the United Nations Sustainable Development Goal of ending the TB epidemic by 2030.
Whilst commendable efforts have been made to address the TB epidemic, including harm-reduction approaches for people living with HIV and/or who inject drugs, much more can be done to tackle smoking in an opportunistic way. The aversion to tobacco harm reduction at the World Health Organisation (WHO) is squandering an opportunity to loosen the vice-like grip of two of Africa’s biggest killers: smoking and TB.
Dr Derek Yach, respected epidemiologist and former Executive Director for Noncommunicable Disease at the WHO, spoke compellingly about this very issue of TB-smoking comorbidity at the recent Africa Tobacco Harm Reduction Forum (see video below):
“60-70% of people with TB smoke. Yet virtually nowhere in the world is there an opportunity to treat TB, and at the same time treat the underlying tobacco issues that most TB patients will have. This means when you send the TB patient having treated their TB, they will go on to die of a tobacco-related cause. This is something uniquely important in an African setting.” – Dr Derek Yach
