Tuberculosis (TB) has remained a major infectious disease in developing and poor countries despite all efforts from health agencies to manage and control it. In fact, even an easy and effective way to diagnose the disease has remained a challenge. Emergence of drug resistant strains has made its management more complex.
The steps
It makes the situation in countries like India, with the highest TB burden in the world, even more serious, requiring urgent attention and novel methods of intervention. It is within this context that two major policy initiatives — to make TB a notifiable disease and to ban serological tests — taken by the combined efforts of several government agencies are noteworthy, timely and laudable.
Making TB a notifiable disease simply means that all TB cases diagnosed nationally and treated in the public or private sector will have to be notified through an information technology-based network dedicated for this purpose. This is an important development because for the first time, India will have a serious and structured process to find out the actual disease burden. This has multiple implications. Not only will this allow doctors and researchers to map the disease spread more accurately but it will also help in identifying areas of high disease burden, the nature of disease and susceptible age groups. This information will be most useful to the TB control programme as it will allow them to focus and/or reorient their efforts for maximum effect, especially for patients in the private sector. Moreover, it will allow patients easy access to appropriate and free TB therapy, ensure compliance and complete cure. A clearer knowledge of the nature and extent of the disease burden will also help State and Central government agencies to plan and execute both short- and long-term strategies for TB control. This will also provide invaluable information for medical scientists involved in the development of new diagnostics, drugs and vaccines against TB.
The second policy decision to ban serological diagnostic tests for TB is no less significant. Serological or blood tests are based on the successful detection of certain molecules (antigens) from the pathogen, or detection of the body’s immune response to the pathogen (antibody response mostly). These are routinely used for diagnosis of diseases like HIV/AIDS, malaria and hepatitis. In principle and in practice, when effective, these tests are economical, easy to use and quick in diagnosis of a disease condition.
Serological testing
However, it has not been possible to develop an accurate serological test for TB so far. The main reason for this is that in disease endemic countries like India, where most of the population has been exposed to TB, these serological tests are completely ineffective. Although healthy, with no symptoms of pulmonary disease, most of us are likely to test positive for TB and in inexperienced hands will perhaps be started on TB treatment. The dependence on such unreliable tests can only do harm, especially serious, in case of TB, because many will end up undergoing TB therapy without any need for it. Several scientific studies have clearly shown that serological tests for TB are not only of no value but also add to the gravity of the problem by resulting in multi-drug resistant (MDR) TB. The World Health Organisation has already advised all TB control programmes against the use of any of these. Thus, the ban by law in India has come not a day too soon. However, it should be emphasised that the ban is only on the serological tests that are used currently for TB and not for serological tests per se. If in future, a reliable and accurate serological test is developed, it will certainly be allowed to be used once its efficacy is proved.
Detecting genetic material
The obvious query in any thinking person’s mind would be: does this ban on serological tests in any way hamper doctors from diagnosing and treating those suffering from TB and requiring urgent attention? The short answer is a definite “no” because these tests are of no value. Moreover, highly efficient tests based on detecting genetic material from the TB bug are now available and in use in many TB endemic countries. These tests are highly reliable, quick and, more significantly, also address the problem of detection of most forms of drug-resistant TB. The challenge seems to be the price of the technology.
There is hope that in the future, home-grown and locally manufactured technologies will be discovered and made available for public use.
These two landmark decisions indicate the positive energy that gets generated when various agencies manage to work in harmonious synchronisation. It is difficult to imagine that such vital decisions could have taken place without care, consultation and the coordinated efforts of all stakeholders in the public sphere involved in the control of TB, along with government agencies like the office of the Drugs Controller General of India, Ministry of Health & Family Welfare (Revised National Tuberculosis Control Programme), Ministry of Communications & Information Technology and Indian Council of Medical Research. All these and several others involved in advocacy to control the disease need to be congratulated. These efforts also reflect the seriousness with which government and health providers in the country have decided to approach one of the most serious health problems in the country. There is hope and every reason to believe that with the combined efforts of public and private health providers, TB and MDR-TB can be effectively managed.
(Prof. Virander S. Chauhan is Director, International Centre for Genetic Engineering and Biotechnology, New Delhi.)
