New Delhi: Even as a Union Health Ministry team of doctors ascertains facts and starts analysis of reported cases of drug resistant Tuberculosis in Mumbai, the Ministry has taken objection to terming such cases as Totally Drug Resistant (TDR).
The central team has also 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.
The Health Ministry said as per WHO norms, such cases can be called `Extensively Drug Resistant-TB` (XDR-TB) and not `Totally Drug Resistant TB` (TDR-TB).
"The term TDR totally drug resistant TB is non- standardized and is misleading. 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," a Health Ministry statement said.
It added 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, while 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).
The Health ministry said the term "totally drug resistant" tuberculosis is neither recognized by the WHO nor by Revised National Tuberculosis Control Programme (RNTCP).
"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. 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," it said.
The ministry said 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 among the new cases and 0.5% among re-treatment cases.
Talking about the Hinduja hospital, which is not accredited to diagnose XDR or TDR, the Health Ministry said, "so far as the report from the 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.
It added a proposal for accreditation of Line Probe Assay (LPA) test has been received from the Hinduja Hospital and is under process.
As of now, the Revised National TB Control Programme has accredited only 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 central team comprises senior Chief Medical Officer, Central TB Division (CTD), Government of India, Consultant (Drug Resistant TB), CTD and National Programme Officer (Lab), WHO-India.