Miles to go in the fight against tuberculosis

While the incidence and mortality of TB is reducing at a slow pace the world over, drug-resistant variants such as RR-TB, MDR-TB, XDR-TB are on the rise.

Over 95% of tuberculosis (TB) deaths in 2015 occured in low-and middle-income countries - with India leading the count. While the incidence and mortality of TB is reducing at a slow pace the world over, drug-resistant variants such as RR-TB, MDR-TB, XDR-TB are on the rise. The short, standardised regiment needed for these variants is available in high-income countries while others continue to suffer as the second line of drugs prove elusive. The maps and graphs analyse the burden of the disease, which is one of the top 10 causes of death worldwide.

Map shows the estimated number of incident tuberculosis cases in 2015 (per 1,00,000 population)

In 2015, an estimated 1 million children became ill with TB and 1,70,000 children died of TB (excluding the ones with HIV). People who are infected with HIV are 20 to 30 times more likely to develop active TB. The risk of active TB is also greater in persons suffering from other conditions that impair the immune system.

 

Down but not enough

The world over, despite better reporting of the disease due to advanced tests, the total number of estimated cases is inching downward. But the rate of decline in TB incidence remained at only 1.5% from 2014 to 2015. This needs to accelerate to a 4-5% annual decline by 2020 to reach the first milestones of the End TB Strategy.

The second wave

Multidrug-Resistant Tubeculosis (MDR-TB) which does not respond to first-line of drugs is on the rise worldwide. The MRD-TB burden largely falls on China, India, and Russia, which account for half the number of global cases. About 9.5% of MDR-TB cases had Extensively Drug-Resistant TB (XDR-TB) in 2015. XDR-TB is a more serious form of MDR-TB.

Better reporting needed

The global treatment success rate fell in 2014, afters years of an increasing trend. The reason being, in the Indian data, 17% of the treatment outcome was categorised as "not evaluated". Thus, India's overall treatment success rate fell from 86% to 74%. The impact was big enough to be registered in the 2014 global numbers.

A top killer

While TB-related deaths are on a downward trend in most high-burden countries, it continues to rise in Nigeria. India and Nigeria accounted for 48% of global TB deaths among HIV-negative people. Globally, the number of TB deaths fell by 22% between 2000 and 2015, but TB remained one of the top 10 causes of deaths in the same year.

Low success rate

Worldwide, only 52% of MDR-TB patients are currently successfully treated.

Lesser still...

Worldwide, only 28% of XDR-TB cases are successfully treated. Wider use of new TB drugs could help to improve the situation.

Key:

SA - South Africa

PAK - Pakistan

NIG - Nigeria

INO - Indonesia

CHI - China

RUS - Russia

WOR - World Average

Data compiled by Vignesh Radhakrishnan, Graphic by Karthick S.T.