7% TB CASES IN CITY INVOLVE CHILDREN

Multi-drug resistant (MDR) TB cases are those in which bacteria that cause tuberculosis develop resistance to at least isoniazid and rifampicin, the two most powerful anti-tb drugs

WHY DOES IT OCCUR? Incomplete treatment

doses of medicines Infection by bacterial strain that is already resistant to many drugs

Extensively Drug Resistant (XDR) TB is a form of MDR TB that is resistant to at least four of the core anti-tb drugs. XDR-TB patients can be cured, but the likelihood of success is lower compared to patients with ordinary or MDR cases In drug-sensitive tuberculosis (DST) cases, isoniazid and rifampicin (which don’t work in MDR cases) are effective

then rushed to the laboratory to isolate the RNA from the samples. “Interestingly, what we found was that we were able to detect bacterial RNA from the masks of patients who were not able to produce sputum. This method in future can be used in the interest of diagnosis,” said research officer Kalpana Sriraman, who developed the method.

Out of the 25,000 TB patients registered with the government in Mumbai, roughly 7% are paediatric cases, said Dr Daksha Shah, the city’s municipal TB officer. “It is a challenge within the programme to diagnose TB in chil-

RISE IN TB CASES FROM 2015 TO 2017

dren because of issues related to sputum collection. This new method is welcomed, but needs to be verified by experts,” she said.

The new method of detection could also help researchers find out how infectious a patient is. “Currently all TB tests check bacterial DNA, which could either be from dead or live bacteria. RNA on the other hand is isolated from viable bacteria. To an extent, RNA levels can tell how infectious or non-infectious a patient is,” said Sriraman added. While both DNA and RNA carry genetic information, DNA stores it and RNA acts as a messenger of the DNA to produce proteins. Researchers plan to study the sample masks collected. “The data using the RNA method will hopefully help us understand the exact time it takes for a patient to become non-infectious, a reason why this study impinges upon the public health angle,” Dr Mistry added. The FMR researchers said that so far, there is no concrete evidence to suggest that it takes two weeks of treatment for a patient becomes non-infectious. A 2014 international study suggested that a day of efficacious treatment may be enough to break the transmission.