If the Lancet’s recommendation on latent TB is to be implemented by the UK and other developed nations, every Indian who wants to visit these countries may have to undergo a nine-month-long medication for latent TB.
However, Lancet’s recommendation is easier said than implemented. A number of ethical and medical issues are involved in treating people with latent TB.
Since two-thirds of latent TB cases are difficult to detect or are likely to be mis-diagnosed, as a precautionary measure, every Indian visitor would be recommended to consume latent TB medicines. This will put a heavy financial burden on individuals. Moreover, it can also create an unnecessary resistance to TB if the person does not carry latent TB germs.
Even active TB germ in India is “shy” in the sense that it does not spread as aggressively as its counterparts in other countries.
“Suggesting that a person undergo tests for latent TB and putting him on medication is a gross violation of human rights. Unless you find the bacteria in the sputum or the lung is damaged, you cannot ask him or her to take medication, which is highly toxic and causes harm to liver,” said Dr Niyaz Ahmed, senior patho-biologist and professor (adjunct), Institute of Life Sciences, University of Hyderabad.
According to Dr Ahmed, the Monteux test based on skin reaction to mycobacterial protein components is cross-reactive and could produce false positive and false negative results in case of 70 per cent of Indians. Similar difficulties could be encountered with the Interferon-gamma test.
India has so far not experienced any institutionalised outbreak like the fatal outbreaks of New York and Kwazulu Natal.
The Indian TB strains are less aggressive and controllable. Indians enjoy a distinct natural protection from latent TB due to the facts that their genetic makeup is different, their strains are different and their immune system is already primed due to a saprophytic antigenic background and/or by Helicobacter infection.
The UK should therefore, not be worried for Indians. They should, in fact, be worried about the Pakistanis and Sri Lankans, who do not have the ancestral strains of TB bacteria (TbD1+) in their countries.