Guest post by Katie Leach-Kemon, a policy translation specialist from the University of Washington’s Institute for Health Metrics and Evaluation.
Tuberculosis is an ancient, stubborn disease – a bacterium that is believed to infect one of three people on the planet.
The screen grab below from the University of Washington’s Institute for Health Metrics and Evaluation’s data visualization tool shows that the rate of premature death and disability (known as DALYs, or disability-adjusted life years) from tuberculosis decreased by 42% between 1990 and 2010. This estimate takes into account changes in population size and ages. It’s also important to note that this figure doesn’t factor in death and disability caused by tuberculosis in people infected by HIV (more on that later).
Looking at changes in rates of DALYs caused by tuberculosis across countries, we see further evidence of progress over time.
The image below from the online tool shows rates of tuberculosis across countries in 1990 compared to 2010. The estimates in the maps are adjusted for differences in population size and ages. In most countries with the exception of countries such as the Democratic Republic of the Congo and Zimbabwe, rates of tuberculosis declined. Despite encouraging signs of success, rates of premature death and disability from tuberculosis remain highest in poor countries that are least able to afford expensive tuberculosis medications and treatment regimens that last six months on average.
Yet another dimension of tuberculosis is its negative impact on people living with HIV/AIDS, whose weakened immune systems are more susceptible to tuberculosis.
If a person who dies from tuberculosis is HIV positive, GBD classifies this as a death due to HIV instead of tuberculosis. In 2010, around 257,000 people died from HIV that resulted in tuberculosis. Since 1990, rates of premature death and disability from tuberculosis among HIV positive people increased steadily until 2005. Scale ups in antiretroviral and tuberculosis treatment were instrumental in bringing these rates down in 2010, as shown in the screen grab below.
Yet another challenge in the fight against tuberculosis is the emergence of multi-drug resistant (MDR –TB) and extremely drug-resistant tuberculosis (XDR-TB) resulting from inappropriate treatment of the disease. Treating MDR- and XDR-TB is much more expensive and complicated than non-drug resistant tuberculosis, thereby presenting an additional challenge to poor countries.
Despite these hurdles, donors and researchers are optimistic that recently-introduced drugs and diagnostic tools as well as vaccines and other drugs currently in development will accelerate the decline of tuberculosis, as discussed in this video from the Center for Strategic & International Studies featuring Dr. Peter Small from the Bill & Melinda Gates Foundation.
As these interventions are introduced and/or scaled up, annual updates of the GBD study will allow the world to monitor progress in reducing the burden of tuberculosis around the world.