Can we stop drug-resistant TB?

Photo by bobbyramakantThis year’s World Tuberculosis (TB) Day on 24 March provided us with the opportunity to review responses to the disease.

TB is both treatable and curable and with the help of proper interventions we should be able to say ‘I can stop TB’. But can we say the same thing for drug-resistant strains of the disease?

Drug-resistant TB levels are at their highest in history, according to the World Health Organization (WHO) report ‘Anti-Tuberculosis Drug Resistance in the World’ released in February. The percentage of people resistant to at least one anti-TB drug is on the rise worldwide and has reached as high as 56.3% in Azerbaijan.

Multi drug-resistant TB, or MDR-TB, is a strain of the disease resistant to the effects of isoniazid and rifampicin – two of the most powerful first line anti-TB drugs. People with MDR-TB are significantly less likely to be successfully treated than people with drug-susceptible strains.

Global estimates indicate that 4.8% of TB cases involve MDR-TB and since treatment is available to just 10% of these people the vast majority will not receive the care they need when they need it.

About 50% of MDR-TB cases occur in India and China, due to their large populations. In Africa, which has also been hit hard by HIV, the number of drug-resistant TB cases is alarming. Across the former Soviet Union, almost half of all TB cases involved resistance to one drug and 1 in 5 cases will involve MDR-TB.

Extensively drug-resistant TB (XDR-TB) is virtually untreatable and is likely to emerge in areas where second-line anti-TB drugs are widely and inappropriately used. XDR-TB is more expensive and difficult to treat than MDR-TB, resulting in higher mortality rates. More than 40 countries have reported cases of XDR-TB, with the United Kingdom reporting its first case last week.

Studies suggest that the transmission of TB, and drug resistant strains of the disease in particular, is more likely to take place where there are high numbers of people living with HIV. Health-care facilities, such as antiretroviral treatment clinics, are just one place where improper controls could put people with HIV at risk of contracting TB.

TB is the most common opportunistic infection and is a leading cause of death among people living with HIV. Improving infection control procedures in health-care settings is just one way to save lives and stop the disease from spreading.

Laboratories in many countries do not have the capacity to test for drug-resistant TB, which makes scaling-up TB programmes difficult. The new WHO report only contained TB drug-resistance data for six African countries since most are unable to test for these strains of the disease. Developing countries’ capacities to test for drug-resistant TB is vital to the fight against the spread of the disease.

More supplies and better quality TB drugs and diagnostic equipment are urgently needed to tackle the problem. Better strategies for combating the disease also need to be developed so that world’s most vulnerable and hard-to-reach communities have access to treatment and drug resistance can be reduced.

Bobby Ramakant-CNS