TB Control: A Tale of Two Infections

Efforts to control TB have split into two very different stories. One narrative tells of a disease that is relatively easy to treat with proper medication and patients who adhere to the treatment plan. The other story is of an infection that is becoming increasingly resistant to available treatments and is beating back efforts to control its growth.

An article in Nature summarizes the divergent stories. One part of the problem is a lack of funding and interest in addition to a careful need to create an appropriate public response. “[R]esearchers have lacked interest in developing drugs and tests, and drug companies have lacked market incentives to do so…But scientists are careful to temper their alarm. In the past decade, researchers and policy-makers have fought for and won a reversal in funding and attention for TB. Several new drugs are in development, and progress is being made towards an effective vaccine,” explains Leigh Phillips in the article.

Additionally, TB is troubling because testing is still behind the curve and an estimated 1 in 4 people with HIV also have TB. The first problem means that determining if a person has TB is still relatively slow and it is hard to know if their TB is resistant to drugs until treatment has been carried out. HIV is a complicating factor since it means that patients are already on a series of treatments and the weakened immune system means that a person is 20-30 times more likely to have latent TB become active.

Why is this happening? Phillips points to poor health systems.

Experts agree that the biggest driver for the growth in drug-resistant TB has been the deterioration in some countries’ health-care infrastructures, including TB programmes, since the 1990s — particularly in the former Soviet bloc. This decline has meant that patients are not diagnosed and treated; and in some countries, over-the-counter availability of anti-TB drugs also encourages people to take inappropriate second-line therapies, accelerating the growth of drug resistance. In a stroke of bad luck, the virulent and often drug-resistant ‘Beijing’ strain of TB, identified in 1995 in China, swept through Russia and eastern Europe just as the region’s public-health provision was being dismantled. “There was a confluence of the biology of the organism and its progress into Russia, where lots of people had a health-care system that was collapsing around their ears,” says McHugh. (In 2010, the Beijing strain was found in around 13% of active TB infections worldwide.) All of this helps to explain why the recent WHO report shows the highest burden of MDR TB in Russia’s Arkhangelsk province and in Belarus, Estonia, Kazakhstan, Kirghizia and Moldova.

The article continues by explaining what countries are doing to slow down the progress of TB before it becomes a major problem. Read the full article here.