Latent TB is still a threat

Every year on March 24, we observe World Tuberculosis Day, a day dedicated to spreading awareness about tuberculosis (TB) and working towards its total eradication. Mycobacterium tuberculosis, the bacteria that causes TB, mostly affects the lungs, however, it can also spread to other regions of the body. TB is one of the top ten causes of death worldwide and the World Health Organisation has set a goal to eliminate the disease by 2030. As per the Global TB Report 2023, India is responsible for 27% of all TB cases worldwide. 

Unlike TB infection, people with TB disease have symptoms that may be mild for many months. Thus, they tend to spread TB to others without even knowing it. Common symptoms of TB are prolonged cough (sometimes with blood), chest pain, weakness, fatigue, weight loss, fever, and night sweats.

It is estimated that approximately one-third of the world’s population harbours the latent form of Mycobacterium Tuberculosis (MTB) Bacilli, which poses a potential risk for future outbreaks. For over a decade, there has been a persistently high incidence and prevalence of TB in countries that also have a high background prevalence of human immunodeficiency virus (HIV). Certain factors, such as weakened immune systems, malnutrition, and tobacco use, can increase a person’s risk of developing TB disease. Recurrent TB disease occurs in patients who were previously treated for TB and develop a new disease episode again later in life. This may happen due to either relapse (the recurrence of the old infection) or reinfection (getting infected with a new strain). Relapse is associated with treatment failure, which can occur due to clinical management complexities leading to sub-therapeutic drug concentrations, drug–drug interactions, altered drug metabolism, or poor treatment adherence by the patient. The symptoms of recurrent TB can vary in clinical and radiologic symptoms and sometimes cannot be clinically distinguished from primary TB disease. In general, TB symptoms are gradual in onset and duration and can last anywhere from a few weeks to several months. However, in young children and patients with HIV co-infection, a more acute onset of disease has been
recorded. 

Gender disparities in TB

Gender disparities play a significant role in TB, with socio-economic inequities, patriarchal structures, poverty, caste, and class making women particularly vulnerable to TB. Women face unique socio-cultural barriers to diagnosis and experience delays or no diagnosis at all.

(The author is chairman, HOD & consultant in pulmonology and a lung transplant physician.)