Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis (M. tuberculosis). TB bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal.
- People can have Tuberculosis (TB) disease and yet not display any of the characteristic symptoms associated with TB, such as cough. This is called subclinical TB.
- India’s national TB prevalence survey (2019-2021) found 42.6 % of the TB cases detected were subclinical and would have been missed if a chest X-ray was not included.
- Recently, the Tamil Nadu TB prevalence survey found 39% subclinical TB cases.
- Subclinical TB could be the reason why the incidence of TB has been coming down so slowly, despite improving case notification and finding as many symptomatic patients as possible.
- TB prevalence surveys done in high-burden countries in Asia and Africa have found a substantial proportion of subclinical TB, with the median being about 50%.
- Depending on how you define it and what symptom complex is used to define subclinical TB, the percentage varies from 30% to 80%.
(Sources: The Hindu and CDC)
