Prof. Dr. Shyam P Lohani

Tuberculosis (TB) is the seventh leading cause of death and a major cause of mortality in Nepal. This contagious disease is caused by bacteria called mycobacterium tuberculosis and mostly affects the lungs. It can also be spread from lungs to other parts of the body, including glands to the abdomen to urinary tracts to sexual organs and even to the skin. It is transmitted through tiny droplets in the air when a patient with active TB coughs or sneezes. Even though a significant proportion of the population carries bacteria in their body (latent tuberculosis) but has not yet become ill and they do not pose threats of transmitting it to other people. Until the immune system is intact or strong, the bacteria in one’s body remain inactive and cause no symptoms. However, there are conditions in which our immune system is compromised and the bacteria become active and cause infection. There have been reports of zoonotic transmission of infection-causing TB bacteria to humans and vice-versa.
There have been growing issues of Rifampicin Resistant Tuberculosis (RR TB), Multi Drug-Resistant Tuberculosis (MDR TB) and Extensively Drug-Resistant Tuberculosis (XDR TB). RR TB is that in which one of the most effective TB drugs called rifampicin is resistant. If two important drugs rifampicin and isoniazid are resistant, then the disease is called MDR TB. In XDR TB, at least four of the most important drugs are resistant which includes rifampicin, isoniazid, one of the fluoroquinolones and the second line injectable anti TB drugs. Both MDR TB and XDR TB require more expensive second-line drugs, toxic as well as require to be administered for a longer period of time. The drug-susceptible TB can turn in to MDR and XDR TB. The most important is the drug compliance issue when a patient with susceptible TB does not complete the full course of the treatment. MDR and XDR TB are transmitted in the same way as drug-susceptible TB.
Epidemiology
About one quarter (two billion) of the world population has latent tuberculosis (TB). People with latent TB are those who are infected by tubercular bacteria but have not yet fallen sick and will not transmit the disease to another person. However, it has been estimated that approximately up to 15 per cent of them have a lifetime risk of developing active disease. People who are HIV positive are 20-30 times more likely to develop active TB (WHO, 2019). Other people with a compromised immune system are prone to develop a disease such as people with severe kidney disease, certain cancers, during chemotherapy, and diabetes. People with organ transplants, malnutrition, a very young age, and advanced age are predisposed to develop active TB. Some drugs predispose people to active TB includes immunosuppressants, drugs for rheumatoid arthritis, psoriasis and Crohn’s disease.
In 2017, 10 million people worldwide developed active TB and 1.6 million died from the disease including 0.3 million who were HIV positive (WHO, 2019). There were 32,474 active TB cases detected in the fiscal year 2018-19 in Nepal and about 6,000 deaths were due to tuberculosis in the same fiscal year. The data shows approximately 89 cases are detected every day and about 16 deaths attributed to TB per day (NTC, 2019). Analysing data from an economic perspective, this preventable, as well as a curable disease, put a comprehensive amount of burden on the national economy as most of the people infected are among the economically productive age group. WHO has estimated that the global burden due to TB is approximately US$ 12 billion annually. It has been estimated that every dollar invested in containing TB will return more than US$ 40 besides a society that is healthy and vibrant.
Challenges
The annual rate of decline of TB is 1-2 per cent. However, to achieve the Sustainable Development Goal (SDG) target of ending the epidemic by 2030 needs a 4-5 per cent rate of decline by 2020 and 10 per cent by 2025 (WHO, 2015). With a TB case incidence rate of 163 per 100,000 and a case detection rate of only 112 per 100,000, there are still about 30 per cent of cases that are undetected every year. Since a patient with one active TB can transmit the disease to 10-15 people over the year, it still is posing threats to hundreds of thousands of people in the country.
There are several challenges for developing countries like Nepal to end this epidemic. Geographical, social, familial, and educational factors pose significant barriers to contain TB. The difficult geography and access to health care facility are one of the barriers to low case detection as well as treatment success. The social stigma associated with the disease deters people accessing health care in societies that are entangled with poverty and a low level of awareness about the disease. Gender bias also plays a crucial role for women in accessing the diagnosis and treatment of TB. The voluntary testing of TB for those Nepali seasonal workers coming from the neighboring countries at the border check posts, the sensitisation and mobilisation of female community health volunteers (FCHV), involvement of community leaders, and extensive mass awareness campaign through various media can be the effective measures for our country to tackle and contain the burden due to TB.

(Prof. Lohani is the Clinical Director of the Nepal Drug and Poison Information Centre and can be reached at lohanis@gmail.com)