AIDS - A Generalized Overview

AIDS (acquired immune deficiency syndrome) is characterized by a profound impairment of immune system. It is caused by the human immunodeficiency virus (HIV) and represents the late stages of an HIV infection. AIDS affects the CD4 cell surface receptor molecule as well as the helper T lymphocytes. Combined therapeutic drugs have reduced plasma bioloads below detectable levels.

However, although the levels may be low, the patient is still considered positive. B lymphocytes are not affected but exhibit altered function due to infected T lymphocytes. The AIDS virus is detected in most body fluids but high quantities are found in blood, semen, and CSF fluid. High risk categories include homosexual, bisexual men; illegal injectable drug use; hemophiliacs; recipients of transfusions prior to 1985; infants of HIV mothers; promiscuous heterosexuals.

Epidemiology and Demographics

Approximately 688,200 cases were reported in US as of 1998. There are 21 million affected individuals worldwide. AIDS can affect individuals of all ages however, 98% of cases occur in those over the age of 12. A majority of AIDS patients are homosexual and bisexual males 54%; 26% are intravenous drug users; and 1% acquired the virus through transfusions. There has been a documented transmission from health care workers to patients however the numbers are strikingly low.

Classification and Staging

AIDS is categorized into three stages A, B, and C. Category A includes patients with acute symptoms or asymptomatic diseases, along with individuals with persistent generalized lymphadenopathy with or without malaise, fatigue or fever. Category B patients have symptomatic conditions, constitutional symptoms of fever, diarrhea and weight loss. Category C are those with AIDS as manifested by life threatening conditions identified by CD4+ T lymphocyte levels of less than 200 per cubic millimeter.

Testing

Because AIDS represents the end stage of an HIV infection, testing normally is initiated if a patient is suspected to have contracted the virus. These tests will look for specific antibodies to the RNA of the HIV virus. The most common test is called an Enzyme-linked immunosorbent assay (ELISA). This test is usually generally the first to be used if a patient is suspected to have contracted the virus. If a positive reading occurs, than a second test is administered to verify the results. Because of the high degree of accuracy that an ELISA test offers, other methods are generally not used. Additional tests include Western blot, polymerase chain reaction (PCR), and indirect fluorescent antibody (IFA).

Treatment

Unfortunately AIDS is a chronic condition and cannot be cured. Most therapies involve the use of cocktail drug therapy to reduce the viral load as well as prevent opportunistic infection. Drug classes such as nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and fusion inhibitors (FI) have all been FDA approved for AIDS therapy. Newer therapies are always on the horizon, however, due to the constant mutation of the HIV virus, it is difficult to formulate drug to combat the virus. As a result, AIDS remains to this day a non-curable chronic condition which ultimately ends in patient mortality.