Kevin M. DeCock, MD, is director of the Center for Global Health at the Centers for Disease Control and Prevention (CDC), based in Atlanta. Last week, he spoke with Science Speaks about the need for better coordination of HIV research initiatives. Here are his thoughts about another issue he sees as incredibly important – the fight against TB. John Donnelly interviewed Dr. DeCock, and the following is in his words:
“TB remains very important. Here are a few research priorities for TB, and I think you can classify the research in different ways: operational, developmental, and epidemiological. The first question, an operational one, is how do we best use antiretroviral drugs? If we use them to prevent HIV, that’s very important because we will also prevent HIV-associated TB. If we use them in people infected with HIV, the question is when do we start therapy? How early to give the best maximum TB prevention benefit?
“Second question: How do we best scale up and evaluate the impact of known interventions? We should look at isoniazid preventive therapy, intensified case finding and infection control. How do we best use new technology such as the Gene Xpert rapid TB test? CDC was heavily involved in a Botswana trial of short-term versus lifetime isoniazid preventive therapy, as well as a study in East Asia optimizing case finding.
“From a development point of view – and this not CDC type of work, this is more with the National Institutes of Health (NIH) and basic science – we need better diagnostics, better drugs, and a better vaccine. In diagnostics, we need point of care tests that accurately diagnose active TB and latent infection and distinguish between those two. We obviously need something better than BCG [Bacille Calmette Guerin – the current vaccine for tuberculosis] for a vaccine. And we need a diverse set of drugs, and ideally drugs that do not need to be taken for six months.
“Finally we still need better epidemiological understanding of what is going on in TB. In some settings, TB is not declining at the rate we might expect. An important question is why is that? Is it because we are not interrupting transmission? What drives it?
“Let me put this another way. We have two things going on. There’s transmission in the community. Say I have TB. I infect you and within the next couple of years, you come down with TB. Another way that cases of TB arise is if you were infected 15 to 20 years ago, say, and the latent disease becomes active. Which of these two types of cases is more important? Ongoing transmission or reactivation of latent infection? Both are probably important, but I’m troubled by the fact that the right things appear to be done in TB prevention, but TB rates are not going down in some places as fast as we would like.”