Sunday, July 22, 2001		Keeping fit

TUBERCULOSIS (TB) has over the centuries been referred to as ‘consumption’ as its cause was not known. Perhaps it was referred to as such because it consumes the patient slowly.

In 1882, the German microbiologist, Dr Robert Koch (who was given the Nobel Prize in 1907 for his discoveries) proved that mycobacterium tuberculosis was the cause of this disease. This was a historic scientific discovery. However, no definite treatment was available till the middle of the previous century and people would go to a sanatorium located in a clean and cool environment (Kasauli, Dharampur, Tanda and others), where good nutrition, cod liver oil and the clean air was expected to cure the disease.

The first effective drug for TB, streptomycin, was discovered by Wakesman in 1945, PAS was added in 1948 and other drugs came subsequently.

The disease has assumed an alarming proportion in the past few years. The National Tuberculosis Control Programme was started in 1962 by the Government of India, but it has not achieved its goal. The revised National Tuberculosis Control Programme was introduced from 1993 in a phased manner and it is hoped that it will fare better.

Incidence in India

India has about 10-12 million TB patients and every year, nearly 1.5 million new cases are added and nearly half a million patients die. This means that one patient is dying every minute of a disease that is curable. These figures relate to pulmonary tuberculosis which is easily diagnosed. Perhaps, the incidence of tuberculosis involving the lymph nodes, bones, joints, gastrointestinal tract, and the brain is much the same.

At the global level the picture is not better. In the annual report on global tuberculosis issued by the WHO on the eve of World TB Day March 24, it has been estimated that 8.4 million people contracted TB in 1999 and the biggest rise in number of cases was in sub-Saharan Africa, where the high incidence was due to the combination of HIV and TB. About 2 million people die of TB and half a million die with concurrent HIV infection. The report goes on to say that although TB is curable only 23 per cent of the people with active TB have access to satisfactory treatment.

The disease is caused by a tiny bacteria which can be seen under the oil immersion lens of the microscope. It is the size of 2-4 millimicron and gives a beaded appearance. It can be seen after a special stain in which one of the steps is discolouration of the stain with acid. These bacteria are resistant to discolouration with acid and therefore known as acid fast bacilli. Doctors often refer to this disease as caused by AFB to avoid mentioning TB in the presence of a frightened patient.

The infection takes place by inhalation of small droplets containing 3-5 bacteria. The bacteria are blown into the air by a patient of lung TB through coughing, sneezing and even talking.

Paradoxically, it is a small droplet which is far more infectious as it keeps floating in the area even after drying as compared to a big droplet which settles on the floor. Good ventilation therefore, is very essential to prevent the spread of TB. Even talking closely to a known patient of TB should be avoided. A tissue paper or a mask helps to reduce transmission of the disease. Dark, damp, closed housing units, which are also overcrowded, are the breeding grounds of TB. Unfortunately, it is not essential to be an inmate of these houses to get the infection. One may get infection during a casual encounter with a patient in a bus, train,market place, cinema hall, social gathering, school or a business place.

It has long been recognised that having TB infection is not synonymous with the having the disease. Otherwise all doctors and paramedical persons would get TB. It has been estimated that one-third of the world population gets infected with this bacteria at one time or the other but only a few people contrast the disease. The secret, therefore, lies in the state of immunity of the person. When the infection is acquired, initially it remains dormant. But the main disease occurs later when the immunity or the resistance of the patient, for some reason, goes down and the disease starts its active course. Anything that impairs the immunity of an individual, therefore, increases the risk of active TB. This is why AIDS, which cripples the immunity of an individual, poor nutrition, administration of strong immunosuppressive drugs, as in the patients of organ transplantation, smoking and diabetes mellitus, all predispose a person to TB.

A new development that is causing anxiety in our own country and to the world community is the multidrug resistant disease, which is difficult and very costly to treat. The multidrug resistant disease is defined as the disease caused by bacteria which are resistant to the two best-known drugs — isoniazid and rifampacin. This has occurred over the years and has now assumed very serious proportion. It has resulted from half-hearted treatment as a result of ignorance of the patients and the medical profession as well as poor implementation of the TB eradication programme at the community level. The patients often do not complete the treatment suggested to them and stop it the moment they feel better symptomatically. Besides, physicians also do not follow the rules of the game and in spite of well-formulated drug regimes at the national level as well as those prescribed by the WHO, every doctor seems to follow his own plan. Somebody has aptly said that there are as many TB treatment plans as there are doctors.

The bacteria also have their own methods of resistance to drugs and they undergo genetic mutation and develop resistance to drugs. Once a person is infected with this kind of TB, the treatment has to be carried out with what are known as the ‘second-line drugs’ which are costlier, more toxic and not easily available. The treatment may cost as much as Rs 200-400 a day for these patients as compared to Rs 22-25 a day for an ordinary patient of TB.

The problem is under active consideration at all levels. At the national level, the revised National TB Control Programme has been started in a phased manner and different blocks in different states are being covered by what is known as the DOTS programme. Primarily, this meant that since patients do not seem to take drugs regularly they should be given drug’s under observation. But this programme means much more than just giving drugs to the patients. It means surveillance of the area, monitoring their progress and providing them drugs under direct supervision. The Tuberculosis Research Centre, Madras, under the ICMR has done a tremendous job in the field. This centre is also responsible for the concept of DOTS. Somehow, the formulations of this centre have not been translated into field programmes effectively.

A gigantic effort would be needed to stem this epidemic and a sociological, educational, economical and medical effort would be needed to make a dent in this.