People & Their Problems

New Delhi, 3 April 2008

Tackling Tuberculosis

NEED FOR NEW EFFECTIVE DRUG

By Radhakrishna Rao

Notwithstanding rapid strides made by India in areas such as healthcare and medical research, the country continues to lag behind in fighting the scourge of tuberculosis (TB), dubbed not long back as a disease of poverty and insanitary conditions. According to the World Health Organisation, India with over 3.4-million tuberculosis patients, accounts for about one fifth of the global figure, making it the most TB prevalent country.

Perhaps the most disturbing feature of the TB scenario here is that 17 per cent of the patients who have availed treatment earlier have developed multi-drug resistance form of the malady. As pointed by the WHO, of all the fresh cases in the country, 1.2 per cent is infected with HIV and 2.8 per cent of all the new cases have been diagnosed with multi drug resistant TB. Union Health Minister Anbumani Ramdoss recently stated that one in the few new cases of TB in the world is in India and this imposes enormous burden on patients, families and communities. Worse, the combination of HIV and TB further complicates the problem. .

A study by the World Bank comes to the conclusion that the economic impact of TB deaths and benefits of TB control among the 22 high-burden courtiers are greatest in China and India, where the combination of growing incomes and decreased TB deaths are translating into a significant economic gain. Clearly, with western drug firms focusing on drugs for diseases prevalent in industrialised countries of the north, the need to evolve a new effective drug for TB has become all the more pronounced

In this context Dr. T.S. Balganesh, Head of Research at Astrazeneca, a pharmaceutical outfit says that India and the world urgently need a new drug against TB because the nature of the disease itself has undergone a radical change. "When we started work eight years ago on a new drug for TB, we began with the concept of developing one that shortened the duration of a treatment. But now my vision of a new drug for TB is any therapy that works and brings benefit to the ailing TB patients, especially those infected with the drug resistant TB. The duration of treatment is not an insurmountable logistic issue, but the need for relief for patient overrides everything else today" he adds.

As pointed out, not long back TB was closely linked to poor hygiene, nutritional deficiency and poor immune conditions. "All of them were pointers that if you had a robust health system and a clean and hygienic environment, TB could be controlled. By and large that has happened in most countries, as the general economic situation has improved and we have been able to control the spread of TB,” observes Balganesh but adds that “with the new societal changes impacting the immune system, you are now seeing TB all over, now in select population group. We are also seeing a more diverse face of TB. That is worrying part because you cannot change lifestyle so easily".

Earlier TB of the lungs was widely prevalent since the immune system of the patient blocked its spread to other parts of the body "That is the way the immune system reacts to TB causing microbe". This particular form of TB is caused by the microbe by name tubercle bacilli, which spreads from one person to another through air. The sneezing by a TB patient releases a large number of germs into the air where they remain suspended for a very long time.

As it is, TB can affect any group. But the diagnosis in children is rather difficult Patients usually have cough in septum lasting for about three weeks. Further, weight loss, poor appetite and extra sensitivity are the other symptoms associated with TB. Liquor consumption and tobacco addiction add to the vulnerability one develops for TB. Carelessness, ignorance and social stigma all conspire to make TB “a difficult to treat disease”. Moreover, many patients stop taking drugs half way through treatment and the poorer ones are not in a position to spare time and money to come to the clinics for proper treatment.

As things stand now, the resistance developed by the disease causing germs to a range of antibiotics, is highly worrying to medical researchers engaged in the battle against TB. In addition to HIV, diabetes is also known to add to the spread of TB. For diabetes is known to compromise the human immune system fighting against TB. Against this backdrop Dr. Balganesh says, "There is now a shift in how TB needs to be perceived in our socio cultural environment as against a century ago, where it was hygiene, nutrition and general well being .We thus must be pragmatic and take necessary steps about what we can do."

The bright spot in India's TB scenario is the successful implementation of the highly- effective DOTS (Directly Observed Treatment Short Course) which is being made available to every segment of the society. As pointed out by the WHO, DOTS is the best prescription to fight the menace of TB. Physicians too specializing in TB treatment say that only a combined crusade with the active cooperation of the government agencies and the NGOs, which incidentally are doing much better work can help combat TB. Experts attribute the spectacular increase in TB cases across the world to the emergence of multi drug resistant strains of the disease causing germs, spread of AIDS and bleak chances of new drugs hitting the market.

In a significant move, a group of Indian scientists has developed a molecule that promises to drastically cut down the time required for the treatment of TB to just two months. This novel molecule which has been tested on mice and guinea pigs and proven to be effective was developed under the Council of Scientific and Industrial Research's "New Millennium Indian Technology Leadership Initiative" by the pharmaceutical major Lupin in collaboration with the Hyderabad University, the National Chemical Laboratory, the Central Drug Research Institute and the Indian Institute of Chemical Technology.

All said and done, public health experts in India have expressed concern that the massive upsurge in HIV/AIDS cases in the country could lead to an increased incidence of TB infection. For most of those who get infected with TB causing micro organism in normal circumstances, don't develop the disease since their immune system keeps the disease causing germs under check. However, once HIV infection sets in they develop full blown TB. Medical experts on their part drive home the point that while a person with only a TB infection has just 10 per cent lifetime risk of developing active TB, the risk is six times higher for those infected with both TB and HIV.

Further, enough evidence has been gathered to show that TB accelerates the regression of an HIV infection into full blown AIDS. In this context, guidelines issued by the National AIDS Control Programme say, "If TB occurs in the early stages of infection when immunity is only partially compromised, it usually manifests as typical tuberculosis that affects the lungs. But as the HIV infection advances, patient can develop other lung infections that resemble tuberculosis or a form of tuberculosis." Guess research needs a greater push. ---INFA

 (Copyright, India News and Feature Alliance)