BMC finds 47.60% contacts of TB patients with latent TB

Mumbai: Eight months after the roll-out of the initiative to screen relatives of pulmonary tuberculosis (TB) patients in the city, Brihanmumbai Municipal Corporation (BMC) found 47.60% (3,645 out of 7,656) positive for latent TB.

TB is a disease caused by Mycobacterium Tuberculosis. A person with latent TB infection is non-infectious. It is said that about 5 to 10% of latent TB patients without treatment will develop TB at some point in time.

The corporation started screening close contacts of TB on July 18, 2022, as a part of the break-the-chain campaign to detect and cut down on transmission. The Interferon Gamma Release Assay (IGRA) tests have been used to detect latent tuberculosis infection (LTBI) among households.

“We are marching towards the end of TB and it is important to cut down on transmission. We, therefore, started screening the close contacts of drug-sensitive TB patients,” said Dr Mangala Gomare, executive health officer, BMC.

She said since the roll-out of the initiative, 2981 contacts found positive were put on the preventive TB treatment.

“It has been a game changer in the early detection of latent TB infection. 1,401 contacts found positive for latent TB have completed the preventive TB treatment,” said Dr Varsha Puri, Mumbai TB officer.

BMC said 664 contacts found positive for latent TB are yet to be put on treatment. “Some had medical reasons, some migrated and some refused. We are counselling them,” said a BMC health official.

While the contact found positive is put on TB preventive therapy- once a week for 12 weeks- BMC health official said the person will be followed up regularly for the next two years. “Those who test negative in IGRA test too will be screened for TB for two years. If the IGRA tests are negative, it implies the person does not have latent TB. As a more effective preventive measure, we will follow up with the person once every six months and screen for TB for the following two years,” explained Dr Gomare.

For IGRA testing, BMC has tied up with a private lab, InfeXn lab for end-to-end management. “We inform the InfeXn Lab about household contacts of newly diagnosed sputum-positive TB patients by district TB officers. The lab technician from InfeXn visits the house with the prior appointment of the eligible contacts and collects the blood sample which is followed by testing,” said a BMC health official.

Seeing the success of the initiative, BMC now plans to also include workplace contacts of TB patients. “Though it is difficult, we will try to include the workplace contacts of TB patients too by counselling them,” said Dr Gomare.

Dr Yatin Dholakia, secretary of the Maharashtra State Anti-TB Association, said identifying latent TB patients and putting them on TB preventive therapy will help prevent and curtail the disease progression. He said only patients who don’t have any active TB, should be put on TB preventive therapy. “It is a good initiative when we are talking about ending the disease by 2025. However, if IGRA is positive, more tests need to be done to ascertain that the person doesn’t have any form of active TB,” he said.