Totally drug-resistant tuberculosis in India
Several reports have been published in India over the last week about a strain of tuberculosis (TB) that is resistant to all existing TB drugs. Here is a preface and early links to new reports. Go to the page on Totally drug-resistant tuberculosis in India for new background, full text of news reports and links, sources and backgrounders (most provided by ProMED-mail, a programme of the International Society for Infectious Diseases).
New Scientist has reported: “We currently have 12 confirmed cases, of which three are dead,” says Zarir Udwadia of the Hinduja National Hospital and Medical Research Centre in Mumbai, and head of the team whose diagnoses of four cases has just been published. The emergence of the disease in such a densely populated city is a major concern as it could spread so easily. “We know one patient transmitted it to her daughter,” Udwadia told New Scientist. “It’s estimated that on average, a tuberculosis patient infects 10 to 20 contacts in a year, and there’s no reason to suspect that this strain is any less transmissible,” he warns.
For patients, the outlook is grim. “Short of quarantining them in hospitals with isolation facilities till they become non-infectious – which is not practical or possible – there is nothing else one can do to prevent transmission,” says Udwadia. The worry is that if it continues spreading, TB will become incurable again and patients will have to rely on their immune system, rather than medical intervention, to overcome the illness – a scenario last seen a century ago.
A communication on ProMED has said: “[Multidrug-resistant TB or MDR-TB refers to tuberculosis that is caused by a strain of _Mycobacterium tuberculosis_ resistant to 2 of the most effective drugs used to treat TB, isoniazid (INH) and rifampin. Extensively drug-resistant TB or XDR-TB refers to a subgroup of MDR-TB strains that are additionally resistant to any of the fluoroquinolone class of drugs (e.g., levofloxacin. moxifloxacin, or gatifloxacin) and any of the 3 injectable drugs used to treat tuberculosis (capreomycin, kanamycin and amikacin).”
Report – Following the discovery of 4 cases of totally drug resistant tuberculosis (TDR-TB) in a Mumbai hospital 3 days ago, 2 confirmed cases with the deadly new strain of TB have been detected at the Rajiv Gandhi Institute of Chest Diseases (RGICD) in Bangalore. But the scarier scenario is this: one among them, a 56-year-old man (the hospital has not disclosed his name), has gone absconding, raising the threat perception many levels higher, considering that he could infect others with the deadly strain.
Report – Even as 2 cases of totally drug-resistant tuberculosis (TDR-TB) have been detected in Bangalore, one of the patients is missing. This poses a grave threat of rapidly spreading the deadliest strain of _Mycobacterium tuberculosis_, the bacterium that causes the disease.
Report – According to Udwadia, the drug-resistant nature of the TB-causing _Mycobacterium tuberculosis_ increases with mutations of the strain often catalysed by incorrect and erratic administration of 2nd-line drugs. “An audit of the patients’ prescriptions showed that 3 of the 1st 4 patients received unsupervised 2nd-line drugs often in incorrect dosages by private practitioners in an attempt to treat their multi-drug resistant TB (MDR-TB). By the time they were referred to us, they had moved from the MDR stage and the XDR stage to TDR-TB,” he said.
Report – News of some of the cases was published on 21 Dec 2011 in an ahead-of-print letter to the journal Clinical Infectious Diseases. That letter describes the discovery and treatment of 4 cases of TDR-TB since last October . On Saturday [7 Jan 2012], the Times of India disclosed that there are actually 12 known cases just in one hospital, the P. D. Hinduja National Hospital and Medical Research Centre; in the article, Hinduja’s Dr. Amita Athawale states: “The cases we clinically isolate are just the tip of the iceberg.” And, as a follow up, the Hindustan Times reported yesterday [8 Jan 2012] that most hospitals in the city — by extension, most Indian cities — don’t have the facilities to identify the TDR strain, making it more likely that unrecognized cases can go on to infect others.