Limited data to support state’s TB preventive treatment of close contacts: Dr Zarir Udwadia

Mumbai: Last year, the state government started a six-month tuberculosis (TB) preventive treatment (TPT) for persons who are in close contact with TB patients. This was done in an effort to prevent the development of TB. However, in the latest edition of medical journal — Lung India — noted pulmonologist and tuberculosis expert Dr Zarir Udwadia questioned the state government’s programme.

As part of the state’s programme, all household contacts of MDR-TB patients, who have fluoroquinolone sensitivity, are put on TPT involving levofloxacin drug treatment for six months.

In the editorial titled- ‘Treating household contacts of MDR-TB patients: Are we being too hasty?’Dr Udwadia, the lead author, said there is limited data to support the approach taken by the state government and therefore, there is a need to evaluate the impact.

Incidentally, the HT in its August 30 report highlighted the fact that the city faces a shortage of at least four crucial medicines for treating drug-resistant tuberculosis that is greatly impacting patients. Several activist and patient groups wrote to the union health minister, Mansukh Mandaviya, earlier this week, appealing for their intervention to expedite the procurement of these medications.

Anti-TB medications, including Linezolid, Clofazimine, Cycloserine and Moxifloxacin, have been in short supply for over a month at both public treatment centres and private pharmacies.

Dr Udwadia in 2012 coined the term “totally drug-resistant TB cases (TDR-TB)” for 12 of his patients in whom none of the known TB drugs worked. It kicked up a worldwide furore with the World Health Organization (WHO) flying in teams to check the extent of treatment-resistant TB cases in Mumbai.

The editorial said that though they agree household contacts of MDR-TB patients are at high risk of TB infection and the disease offering these exposed contacts appropriate treatment is a huge priority if we are to ever achieve TB elimination goals. Despite the considerable risks to contacts, the editorial pointed out that there are many unanswered questions about the efficacy of any treatment in such patient populations.

The paper said in the absence of enough research, all the household contacts of MDR-TB patients should be very carefully followed up and promptly treated as soon as they are known to be infected. “This is a better strategy than all healthy contacts receiving treatment of unknown efficacy with toxic drugs, which may predispose them to possible future resistance,” read the editorial.

The editorial also quoted a study from South Africa by Verver and colleagues which used such genotypic techniques and showed that there was only 20% concordance between households, with the rest of the infections being acquired in the community due to “extensive social mixing.” “Treating such contacts infected by a sensitive strain, as if they had MDRTB, would clearly be inappropriate,” the editorial said.

TPT for MDR-TB contacts with 6 months of daily levofloxacin was first discussed in the WHO consolidated tuberculosis (TB) guidelines based on “low quality evidence with the conditional and cautious recommendation.” The editorial said we are carrying forward the same recommendations without accounting for the multiple challenges faced in a high TB burden country like India.

The editorial also pointed out that there are no clear answers on the optimal agents we should be offering household contacts exposed to a patient with MDR‑TB. “There is no clear data on a)whether a single agent will suffice or whether we should use combination therapy or b) whether the drug (s) chosen should be standardised or individualised as per the drug sensitivity test (DST) of the index case. The later approach would hugely add to the complexity,” said the editorial.

Dr Sunita Golait, state TB officer said it is a Central TB division directive that the state has followed. “Previously it was only for children (less than 5 years). Last year, on the Centre’s directive, the programme was rolled out for adults too and for close contacts of all TB patients including MDR-TB,” she said.

Dr Golait added no programme is rolled out without research/study. “I have not read the editorial and it is difficult to comment,” she said. With regards to the shortage of TB medicines, she said it will be fixed in a week’s time.

While the state rolled out the TPT last year, Brihanmumbai Municipal Corporation said they are in the process of rolling out the TPT with close contacts of TB patients with proven fluoroquinolone sensitivity. The city’s TB office also runs a TPT where close contacts of pulmonary TB in Mumbai are screened using Interferon Gamma Release Assay (IGRA) testing to detect latent tuberculosis infection (LTBI). The contact found positive is put on TB preventive therapy- once a week for 12 weeks. They are put on Isoniazid and Rifapentine treatment based on the IGRA findings. Between July 18, 2022 till March 23, 2023, 47.60% (3645 out of 7656) positive for latent TB.

HT reached out to Dr Zarir Udwadia but he did not respond till the time of going to press.