AIDS increases TB death risk

TUBERCULOSIS, the number one killer in India -- two million cases of active TB are diagnosed each year -- and the AIDS epidemic are showing a disturbing tendency of coalescing and infecting the same individual (WorldAIDS, No 23).

The risk groups of both diseases overlap in many countries in the developing world and people with the AIDS-causing human immunodeficiency virus (HIV) are more likely to develop active TB. One-third of the world's population is latently infected with TB. The World Health Organisation estimates some 4.5 million people, 98 per cent of them living in the developing world, are infected with both TB and HIV. "It has been proved without doubt," says WHO, "that dual infection of Mycobacterium tuberculosis and HIV triggers off active tuberculosis because of the weakened immune system."

In developing countries, 14 to 30 per cent of the AIDS patients have TB and 12 to 60 per cent of the TB patients are HIV positive. HIV victims suffering from active TB are three to four times more likely to die than active TB patients not infected by HIV.

AIDS patients are more likely to contract TB because it is more virulent than the other diseases that infect them due to their reduced immunity. TB occurs early in the course of HIV infection, often before signs of AIDS appear. An added complication is that thiacetazone, the main drug used to combat TB, can produce severe and sometimes fatal side effects in people with HIV.

Evidence from Africa indicates TB cases have increased over the past five years due to the rising incidence of HIV. Tanzania, Burundi and Malawi all report huge increases in the number of active TB cases. In Uganda, confirmed active TB cases doubled between 1984 and 1987. WHO estimates about 60 per cent of the TB patients in Uganda and Zambia are infected with HIV. In Africa, TB has become the primary cause of death in adults with HIV.

In Asia, where about two-thirds of the world's TB-infected population is concentrated, experts fear a spread of HIV-TB infection. According to one doctor, there are millions of people in Asia infected with TB just waiting for HIV to activate it.

The number of HIV-TB infected people in India is increasing, says Indian Health Association founder and secretary Ishwar Gilada. Whereas a 1988-89 survey at a Bombay hospital found 2 per cent of the TB patients were infected with HIV, this figure has now risen to about 15 per cent, says Gilada.

Though TB is not a major problem in the developed world, WHO says incidence of the disease has risen in nine European countries. In southern Europe, a growing number of cases, attributed primarily to immigration, seem to be linked to HIV. In Spain and Italy, TB infection rates among people with HIV are as high as 10 per cent.

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