Context

Scientists have discovered a Cure for the Deadliest Strain of Tuberculosis.

About

• Tuberculosis has now surpassed AIDS as the world’s leading infectious cause of death, and the so-called XDR strain is the ultimate in lethality. It is resistant to all four families of antibiotics typically used to fight the disease.
• Only a tiny fraction of the 10 million people infected by TB each year get this type, but very few of them survive it.
• There are about 30,000 cases in over 100 countries.
• Last year, there were more than half a million drug resistant TB cases in the world.
• The treatment to cure this strain is extraordinarily difficult. A typical regimen in South Africa requires up to 40 daily pills, taken for up to two years.

Tuberculosis

• Tuberculosis (TB) is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs. Tuberculosis is curable and preventable.
• TB is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air.
• Anti-TB medicines have been used for decades and strains that are resistant to 1 or more of the medicines have been documented in every country surveyed. Drug resistance emerges when anti-TB medicines are used inappropriately, through incorrect prescription by health care providers, poor quality drugs, and patients stopping treatment prematurely.
• Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to isoniazid and rifampicin, the 2 most powerful, first-line anti-TB drugs. MDR-TB is treatable and curable by using second-line drugs. However, second-line treatment options are limited and require extensive chemotherapy (up to 2 years of treatment) with medicines that are expensive and toxic.
• In some cases, more severe drug resistance can develop. Extensively drug-resistant TB (XDR-TB) is a more serious form of MDR-TB caused by bacteria that do not respond to the most effective second-line anti-TB drugs, often leaving patients without any further treatment options.

New Treatment

• It is a three-drug regimen consists of bedaquiline, pretomanid and linezolid — collectively known as the BPaL regimen.
• Pretomanid is the novel compound developed by the New York-based non-profit organisation TB Alliance and which received the FDA greenlight on Wednesday.
• This treatment involves only five pills of the three drugs daily taken over just six months.