One key challenge is the lack of uniformity in the diagnostic algorithm between the private sector and the public sector in this field
Tuberculosis continues to kill two Indians every three minutes and nearly 1,000 every day, yet the task of accurately diagnosing the disease gets relatively low priority. This often leads to delayed treatment, perpetuating the spread of TB and drug-resistant TB.
A key challenge in diagnosis is the lack of uniformity in the diagnostic algorithm between the private and public sector. In the public sector, sputum smear microscopy has been the primary method for diagnosis even though it misses half the cases.
In India’s vast private sector, until recently serological (blood) tests were used to diagnose TB even though they have no clinical basis for diagnosing TB. Yet, more than 73 types of serology kits for TB diagnosis are being marketed and produced, mostly in China and India. The market in India for these tests was estimated at a $15 million a year. In 2012, India issued a notification banning the manufacture, sale and distribution of serology-based testing kits. However, the private sector continues to recommend this test. Though the imports have stopped, Indian manufacturers continue to produce the kits, using loopholes in regulation at the State level.
Another disturbing development is the increasing pressure on the scientific community from corporates to publish results favouring the use of blood tests for TB detection. Recently, I was invited to address a TB symposium at the Mahatma Gandhi Institute of Medical Sciences in Sevagram, Maharashtra, where I was requested to voice my opinion against the ban and recommend that it be lifted. The organiser claimed he had discovered an indigenous serology kit for accurate TB detection and correct results. Unfortunately this was further supported by a group of leading scientists from the Central India Institute of Medical Sciences, Nagpur, who claimed that their serology test was accurate and was being routinely utilised for diagnosis. When I questioned the veracity of their data and efficacy claims, a barrage of letters against me was addressed to officials of the Government of India and participants for not supporting indigenous talent and technology. Interestingly, it was claimed that their tests are approved by the Food and Drug Administration (FDA) of Maharashtra and Karnataka. It is an irony that local FDAs are not under the jurisdiction of the Drug Controller General of India (DCGI) and State FDAs need not follow the instructions of the DCGI in approving such local kits/devices. So paradoxically, a test that a national FDA bans, the State approves.
Another disturbing trend is the increasing use of Interferon Gamma Release Assays to detect active TB, though the test is intended to diagnose latent TB, especially in children. Here again, while the DCGI has declined to renew the import licence for the foreign IGRA kit, a similar indigenous kit is being marketed and is misused for active TB diagnosis. The problem lies in the unregulated autonomy of the State FDAs, which can approve any test on the basis of some local understanding.
Fortunately, there are tests available today that are capable of providing timely and correct diagnosis, ensuring that no one is wrongly diagnosed. These tests include the polymerase chain reaction, line probe assay and GeneXpert or cartridge-based nucleic acid amplification test.
There is a need to investigate the manufacture of serological kits for TB in India and why local FDAs have not initiated action in this regard. Novel innovations developed by scientists must be debated and validated under the supervision and leadership of the Indian Council of Medical Research. The local FDAs are given autonomy to promote business in the respective States, but ethics and patient safety cannot be compromised. Hence, all approvals of new products must be reported to the Central Drugs Standard Control Organisation.
For evidence-based diagnosis, the Government of India’s Revised National Tuberculosis Control Programme, or RNTCP, has equipped several laboratories with an aim to ensure higher detection rates. The government should fund research and development on key issues.
One should not wait for a crisis to occur. Leading regulatory bodies like the DCGI must take a proactive role so that State agencies become answerable for incorrect actions. Until this happens, we will be depriving the patient of the basic right to be diagnosed and treated correctly.
(Dr. Sarman Singh is Professor and Head, Clinical Microbiology Division, Department of Laboratory Medicine, AIIMS, Delhi.