RBC, platelate and WBC; from Left to Right
Normal CD4 count is 500-1200/cubic millimeter of blood. In HIV infection the count decreases. As CD4 cells constantly circulate in the blood to every part of body and attack the foreign intruder pathogens; a decrease in their number makes the defense system weak and vulnerable to any infectious disease. At that point HIV infection turns to the disease called AIDS (Acquired immune-deficiency syndrome).
In 2009, the WHO recommended that ART (Anti-retro-viral therapy, as HIV is a retro-virus) should be started when a key measure of immune system strength, the CD4+ cell counts, comes down to a concentration of 350 per cubic milliliter of blood. South Africa has instead decided to stick with the old standard of 200/cubic milliliter of blood to start ART.
Image via WikipediaThis strategy may be responsible for the alarming number of new cases of AIDS and unhindered spread of the disease in Africa.
While initial costs of adopting the new guidelines will be greater because of the increased number of people will be eligible for the treatment but, in the long run costs would be saved because of the reduced number of new infections