(Photo from MSF website)
Today – March 24 – is World Tuberculosis Day 2009. In respect for this global killer, I thought I would try to summarize what I think some of the key challenges are to an effective global response against this disease:
1. Epidemiology: Approximately one third of the World is infected by TB (1 in 3 people!), although only a small fraction of those with TB infection will ever develop active TB, which may occur any time after infection, sometimes many years later. New cases today are a function of exposure patterns that happened many years in the past. Among other things, this epidemiological profile means that TB will be hard to isolate, that it will require a screening strategy that will need to test a lot of people but may only be able to isolate a few cases, that controlling the movement of TB patients is difficult, and that actions taken today may actually not have impact until much further into the future.
2. Diagnosis: Current methods for screening patients with TB are sub-optimal. Sputum based methods are best suited for population based screening, but miss many cases. Culture and X-ray methods are better tests but are not affordable for widespread use. As a result, TB diagnosis remains a major challenge.
3. Treatment: TB treatment requires treatment over long periods of time therefore adherence and follow up are important to effectively treat this disease, but as most public health people know, long treatment courses are a recipe for disaster. No matter the disease, people in general are terrible patients, and despite the obvious private benefits, the treatment of chronic diseases will always be challenging. That just reminded me, I forgot to take my malaria pill again last night.
4. Drug-resistant strains: Sub-optimal treatment of disease, which despite our best efforts is occurring, is leading to higher levels of resistance among strains of TB. So efforts to scale up treatment more broadly are facing new challenges from increased drug resistance. There are only a limited number of effective drugs against TB and therefore it is really important to ensure that these drugs remain effective.
5. Co-infection with HIV: HIV infection weakens the immune system of patients meaning that infected patients are more likely to develop active disease and more likely to develop more severe forms of the disease. TB infection can also have a negative feedback on HIV disease progression.
To read more about TB, check out:
The Stop TB website.
MSF has also launched a new report today on TB.
Paul Chinnock discuses TB here.Share on Facebook