Thursday, August 22, 2013

Required: Reliable TB diagnosis in private sector

There are diseases against which we humans are helpless. In many cases, only thing we can do is to prolong the inevitable death.... At the same time there are diseases – perilous ones, killing hundreds of thousands every year – we can get rid of with early diagnosis and proper medication.

If someone is dying because of illness in first category, we are completely helpless. What about people dying because of diseases in second category?

This question remembered me about a story I studied in school days. In Malayattoor Ramakrishnan’s semi-auto biographical novel – Verukal (Roots) - there is a character called Ramu who died because of Rabies. What makes this death different is, Ramu was about to see the doctor for diagnosis after bitten by a mad dog; on the way one quack advised him to go for blood testing. Blood test results were negative and he happily went back to home. After a number of weeks he started showing the symptoms of rabis and consulted a doctor. Doctor told them that, Rabies diagnosis is usually made from saliva, urine etc not blood. Had they know it earlier, Ramu might have lived for many more years.

Accurate diagnosis is the first battle against the war on any disease. If we can’t do it properly, then any amount of excellence in other fields won’t help the patient.

This rule is not different for TB too.

On 7th June 2012, GoI banned manufacture, sale, import, distribution of serology based kits (conducted on blood samples) for TB diagnosis. Problem with serology is its unreliable results. It often gives false positive and false negative results. According to a 2012 TOI report, “15 lakh TB serological tests are estimated to be done in India, with patients spending an estimated Rs 75 crore ($15 million) annually on such tests.”

By banning GoI did a fine job. However, another problem popped up. With serology based tests are out of scope, private labs turned in to Interferon Gamma Release Assays (IGRAs) for detecting TB. Problem with IGRA is, this test is for latent TB, not for active one.

What time demands is a reliable test for active TB in private sector as well.

In public sector GoI, under Revised National TB Control Programme (RNTCP), provides TB diagnosis and treatment free of cost to all patients. However in Indian medical sector government is not an all pervading force.

According to a Guardian report, “More than 70% of Indians seek first contact medical care in the private sector, and more than 50% of all TB patients in India are treated in the private sector... patients often begin seeking advice in the informal private sector (chemists and unqualified practitioners), then seek care from qualified practitioners, and eventually end up in the public sector for free treatment... while they do this, they continue to transmit the infection to others”

In such a situation, if we don’t have a reliable process for diagnosing TB in private sector...?

Delayed diagnosis will not only make it an epidemic, drug resistant but fatal as well.

Guardian report further points out that,

“TB testing practices in the private sector are completely different from those in the public sector. All over the world, sputum is the most important sample for diagnosis of lung TB... includes the traditional sputum smear test...Although not highly accurate, this test is still useful (and cheap) and should be more widely used in the private sector... WHO endorsed a new, rapid, two-hour DNA test called GeneXpert, which can diagnose TB with great accuracy and can also detect those with drug-resistance... another DNA test called Line Probe Assay... detect drug-resistance with high accuracy... liquid culture... is considered the gold standard for TB diagnosis and is the only test that can detect resistance to all major TB drugs.

DNA tests are expensive (in public sector it is subsidised to great extent) in private sector. Considering the importance of early diagnosis of TB and possibilities of transmission of diseases through air, it is very much critical to make an early as well as accurate diagnosis. Government can remove import duties on diagnostic kits and offer subsidies to private sector, if required to reduce the costs.

What time demands is right diagnosis in early stage.


For more information on TB read my earlier article – “TB - The Killer Disease and India”


1. Ban on inaccurate blood tests to diagnose TB - TOI
2. Experts question new TB test, say could lead to drug resistance - IE
3. Accurate TB tests needed in the private sector - Guardian
4. TB Facts

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