A complex case

THE Human Immunodeficiency Virus (HIV) is a complex one which rapidly changes its structure. This is a reason why it has been difficult to find a cure or develop a vaccine for Acquired Immune Deficiency Syndrome (AIDS). HIV is part of a closely related g roup of viruses known as retroviruses. As the name suggests, this group goes against the natural order of things: instead of following the biological rule in which genetic commandments flow from the master molecule deoxyribonucleic acid (DNA) to ribonucl eic acid (RNA), retroviruses reverse the process. The effect of the reversal of genetic hierarchy is catastrophic. Simply put, it enables HIV to incapacitate the white blood cells to fight disease.

It is important to distinguish between full-blown AIDS cases and an HIV infection. People infected with HIV may take between seven and ten years to develop AIDS. Other factors such as malnutrition and poor health could speed up the progression of the dis ease.

Tuberculosis (TB) and HIV form a deadly duo with the latter riding piggyback on the passive TB bacterium. The bacterium is supposed to be present in one-third of the world's population but it gets activated only if the immune system is weak. The presence of HIV not only severely affects a TB carrier but results in the mutatation of the bacterium, which becomes resistant to known TB cures. The prevalence of multi-drug resistant TB (MDR-TB) is worldwide. The World Health Organisation (WHO) estimates that the rate of MDR-TB in India is on the increase, especially in Mumbai where HIV infection rates among TB patients is estimated to be above 40 per cent.