new MDR-TB test

If patients failing to complete the treatment, and wrong medication by the medical practitioners often leads to drug resistance in TB patients, diagnosing people who are resistant to the first-line drugs is fraught with long delays.

Starting next year, India will have a rapid test capable of diagnosing multi-drug TB (MDR-TB) in just two days. The conventional method used for diagnosing MDR-TB takes as long as 6-12 weeks for knowing the results. Even the rapid test being used takes about 21-28 days.

The long delay in diagnosing multi-drug TB leads to only about 2 per cent of such cases being diagnosed. The delay could also lead to the spread of the multi-drug resistant TB strains.

India is now preparing itself to evaluate the Haine MDR-TB test before it uses it on a regular basis. Evaluation is necessary to know the ability of the test kit, to detect multi-drug resistant TB, in the population where it is going to be used.

Five sites

The rapid test would be evaluated at five sites — SMS Medical College in Jaipur, Government Hospital for Thoracic Medicine in Chennai, ST Demonstration Centre in Ahmedabad, ST Demonstration Centre in Hyderabad, and AIIMS, Delhi.

In addition to the five sites, the Haine test would undergo evaluation at the Tuberculosis Research Centre (TRC), Chennai. “The evaluation at TRC is under the Model DOTS Project of the WHO,” said Dr. Ranjani Ramachandran, Assistant Director at TRC.

“TRC would soon start evaluating it and we will have the result in two months’ time,” Dr. Ramachandran said.

“The multicentric trials would begin in August,” said Dr. Yamuna Mundade, Medical Officer of the Foundation for Innovative New Diagnosis (FIND), India. FIND, along with the WHO, Stop TB Partnership and UNITAID is involved in making the test available in the developing countries.

Molecular testing

The test, based on molecular testing for diagnosing MDR-TB makes it necessary to evaluate the test kit in the population where it is going to be used.

The rapid test looks for the resistant genes in the sputum sample. The test will be compared with other rapid tests that are currently being used. It will be tested using samples where the multidrug resistance is already known as well as samples where it is not known.

“The initial validation will be using 250 samples from all sites and another 200 samples for demonstration in each site,” Dr. Mundade said.

Explaining on the need to do a multicentric testing, Dr. Mundade said: “There is a possibility of genetic variation for drug resistance [in India].” Genetic variation within India is a well known fact.