The human immune deficiency virus, HIV, is responsible for a syndrome where the immune system becomes unable to fight off infection (AIDS). HIV attacks the immune system, leading to a chronic and progressive illness that makes a person susceptible to infections and cancer.
People infected HIV usually show no immediate symptoms. A few weeks after being infected, characteristic signs of viral illness may appear: fever, sore throat, fatigue, enlarged lymph nodes, muscle and joint pain. The symptoms will pass, and so the victim may think it was just a cold or flu.
This stage is followed by the early signs of HIV infection: weight loss with no apparent reason, constant fatigue, low stamina, fever that lasts several weeks, night sweats, diarrhoea, either episodic or constant, dry cough, enlarged lymph nodes in the neck, groin area and armpits. Bruise-like spots may appear on the skin and the inside of the mouth.
Although some people can remain symptomless for many years, HIV starts destroying the immune system that guards against infection. This eventually leads to full-blown immune deficiency – AIDS.
HIV-infected people are not eligible to be donors.