According to the National Institutes of Medicine, AIDS or Acquired Immune Deficiency Syndrome, is advanced HIV infection and is the sixth leading cause of death among people ages 25 to 44. HIV in its advanced stage severely impairs the body's ability to fight infection. As of 2008, there are 33 million people in the world living with HIV/AIDS, including 2.1 million children under the age of 15. The primary symptoms of AIDS are a CD4 count of less than 200 or having an opportunistic infection.
CD4 Count
A patient with HIV infection will have their blood counts monitored closely. The health care provider will check the red blood cell count to watch for anemia and a decrease in white blood cell count. A specific set of white blood cells, called T-cells or T-lymphocytes, play an important role in fighting infection in the body. The HIV virus attaches itself to the T-cells and destroys the cell. Unchecked, HIV can destroy the entire T-cell line, enabling opportunistic infections to take hold in the body. When checking the number of T-cells or T-lymphocytes that have been affected, a physician will order a CD4 count. A CD4 count of less than 200 is considered an AIDS defining condition, whether the patient is symptomatic or not.
Pneumocystis Pneumonia
Pneumocystis pneumonia (PCP), is a fungal infection that occurs in HIV positive patients with low CD4 counts. It is an opportunistic infection that is known as an AIDS defining illness. PCP in HIV positive patients develops slowly over weeks and months, according to the National Institutes of Health. Patients initially notice some shortness of breath with exertion, which advances until they are short of breath at rest. Fever, weight loss and possible respiratory arrest can occur. PCP is caused by Pneumocystis jirovecci, a ubiquitous soil fungus.
Kaposi's Sarcoma
Kaposi’s Sarcoma is a cancer of the skin, lungs and bowel, according to the National Institutes of Health. CD4 counts don’t necessarily have to be low, but the lower the count, the more likely the disease will occur. Kaposi’s Sarcoma is associated with the herpes virus HHV-8, or human herpes virus 8, occurring more frequently in men than in women. Kaposi’s causes abnormal tissue to grow under the skin and creates purple and red lesions that can be painful. These lesions can also grow in the mouth, nose and throat and in other organs. Bleeding may occur when the lesions invade the digestive tract. Kaposi’s is an AIDS defining illness.
