Central team examining Drug Resistant TB cases in Mumbai

A team of doctors, deputed by the Union Ministry of Health and Family Welfare, has reached Mumbai to ascertain facts about the reported cases of Drug Resistant TB cases.

The Ministry says, the cases should be called 'Extensively Drug Resistant-TB' (XDR-TB) and not 'Totally Drug Resistant TB' (TDR-TB) as per WHO norms, an official release said.

The central team has started analysis of the situation and is in touch with the health authorities of Maharashtra, Mumbai Municipal Corporation, while also involving experts from concerned stake-holders, including the Hinduja Hospital, Mumbai.

Hinduja hospital is not accredited to diagnose XDR or TDR, the release said. "So far as the report from Hinduja Hospital is concerned, this Hospital Laboratory is not accredited by the Revised National Tuberculosis Control Programme, for culture and sensitivity for second line drugs to diagnose Extensively Drug-Resistant (XDR)/Totally Drug Resistant (TDR) cases and is only accredited for conducting Drug Susceptibility Testing (DST) by liquid culture and sensitivity for first line drug only," it said.

Recently, a proposal for accreditation of Line Probe Assay test (LPA) has been received and is under process, it added.

As of now, the Revised National TB Control Programme has accredited only following three labs for conducting quality-assured second-line anti-TB drug susceptibility testing of flouroquinolones and injectables: National TB Institute (NTI), Bangalore; LRS Institute of TB and Chest Disease, New Delhi, and National Institute of Research in Tuberculosis, Chennai.

The use of term TDR ??" Totally Drug Resistant is non standardised and misleading, according to the statement.

The term "totally drug resistant" tuberculosis is neither recognised by the WHO, nor by the Revised National Tuberculosis Control Programme (RNTCP), it said.

"For now, these cases are defined as Extensively Drug Resistant Tuberculosis (XDR-TB), according to WHO definitions, and accordingly, can be managed by national XDR-TB treatment guidelines," it added.

Testing for resistance beyond XDR-TB is not advocated by WHO and poor clinical response to treatment has not yet been correlated with diagnosis of drug resistant TB, without Laboratory conformation from Accredited Labs.

Multi-Drug Resistant (MDR-TB) is defined as resistance to at least isoniazid and rifampicin (two of the most potent first line anti-TB drugs), with or without resistance to other first-line drugs, it said.

Extensively, Drug-Resistant TB (XDR-TB) is defined as resistance to at least Rifampicin, Isoniazid (i.e. MDR-TB) plus resistance to any fluoroquinolone, and to any of the 3 second-line injectable drugs (capreomycin, kanamycin and amikacin).

Current WHO recommendations advise against the use of the Drug Susceptibility Testing (DST) results for second line drugs beyond those used to identify XDR-TB to guide treatment.

Any type of Drug Resistant TB can only be diagnosed by Laboratory Test and not by clinical examination alone.

Preliminary results of second-line DST for MDR-TB patients from DOTS Plus sites and also isolates collected from Gujarat and Maharashtra drug resistance surveys show that there is not yet any XDR-TB amongst new cases, it said.