First discovered in 1981, AIDS has taken the lives of over 25 million people, and the World Health Organization today classifies HIV as a global pandemic. While there is no cure for HIV and AIDS, antiretroviral drugs have turned the prognosis of the disease from fatal to manageable. Here is a guide to understanding the cause and treatment of HIV and AIDS:

HIV (human immunodeficiency virus) attacks and weakens the immune system — which is the body’s primary defense from infectious diseases. When the immune system is compromised, the body is less able to prevent and fight infection. If left undetected and untreated, HIV infection can advance over time into AIDS (acquired immunodeficiency syndrome), which is the most advanced stage of HIV infection.

Flu-like symptoms will usually appear within a month or two after the initial HIV infection. These symptoms can include: fever, muscle soreness, rash, headache, sore throat, mouth or genital ulcers, swollen lymph glands, joint pain, night sweats and diarrhea. The symptoms of primary HIV infection can last for a few weeks. After this time, HIV enters into a latent stage, which can last around eight to 10 years, and during this time, there are usually no signs or symptoms of HIV infection. As the virus multiplies, the infection grows more severe, and the following symptoms may develop: fever, fatigue, weight loss, cough and shortness of breath. The presence of HIV is usually determined by a series of blood tests.

HIV is transmitted through body fluids including blood, semen, breast milk and genital fluids. Basic bodily contact like shaking hands, hugging or closed-mouth kissing does not cause HIV infection. HIV infection is most commonly caused by unprotected sex or drug users infected with HIV sharing needles or syringes.

HIV infection is best prevented by limiting the exchange of body fluids. Individuals at risk should always use a condom during sex, and intravenous drug users should not share needles or syringes. A woman who is pregnant and HIV-positive should not breast feed after giving birth. Do not share razors, toothbrushes nor any other object that might have blood on it. Anyone infected with HIV should still use these precautions with others who are also infected.

AIDS is the most advanced stage of HIV, and it is the final stage for a fatal case. HIV primarily affects the immune system’s CD4 cells, which are white blood cells that first respond to infections. As HIV takes its toll on the immune system, the body’s CD4 count decreases. Untreated HIV typically takes about a decade to advance into AIDS, but early intervention and treatment can significantly prolong that time period.

Treatment depends on a person’s overall health, including: the immune system’s health, amount of virus present in the blood, pregnancy or an individual’s willingness to commit to lifelong treatment. A treatment regimen most commonly consists of antiretroviral therapy.The U.S. Department of Health and Human Services recommends a minimum of three different HIV medications from at least two different drug classes. There are six drug classes that fight HIV in different ways. One class may keep HIV from reproducing itself. Another can block HIV from entering the immune system. Visit the Federal Drug Administration’s website to learn more about anti-HIV medication. For more information on HIV and AIDS, including federal resources for people infected with HIV, visit www.aids.gov.