Human Immunodeficiency Virus

Human immunodeficiency virus (HIV) is the virus that causes AIDS. HIV destroys CD4 cells, immune cells that help the body fight off infection and disease. A low CD4 cell count is an indication that your immune system is weakening and not able to protect you adequately. A CD4 cell count of less than 200 is one of the criteria for diagnosing AIDS. AIDS causes you to become susceptible to certain types of infection, parasites and some cancers. Following infection with HIV, it may take up to 10 years to develop AIDS. The National Institutes of Health reported in February 2005, however, that a new strain of HIV appeared to progress from infection to full-blown AIDS in less than 20 months, and possibly in only two to three months.

Causes

HIV is spread through sexual contact, shared drug needles or other situations in which people are exposed to infected blood, semen or vaginal secretions. For you to become infected with HIV, the blood, semen or vaginal secretions must enter your body.

HIV is not spread through:

• Using public restrooms

• Coughing or sneezing

• Hugging or touching

• Food or water

• Shared work or school space

Even if an HIV-infected person is otherwise healthy and has not yet developed AIDS, he or she can spread it to other people. If you already have another STD and are sexually active with a person with HIV, you're at greater risk for becoming infected with HIV.

Symptoms

Early symptoms of HIV, occurring weeks to months after exposure, include swollen lymph glands and flu-like illness. Later symptoms, occurring years after exposure, include:

• Persistent fevers and night sweats

• Persistent fatigue

• Unexplained weight loss or loss of appetite

• Prolonged diarrhea

• Swollen lymph nodes

• Skin infections such as ringworm, candida, thrush or molluscum contagiosum not normally seen in healthy adults

• Purple bumps on skin or inside mouth and nose

• Recurrent respiratory infections, shortness of breath or dry cough

HIV is diagnosed by testing blood for the presence of antibodies to the virus. HIV tests may not be positive immediately after infection because it may take three or more months for your body to develop these antibodies. In some cases it can take up to six months for an HIV antibody test to become positive. During that period, however, even though your test is negative, you remain infectious to other people.

There is no cure for HIV/AIDS, but many medications can dramatically prolong the lives of people infected with HIV by slowing replication of the virus and subsequently slowing damage to the immune system. In July 2006, the FDA approved a single-pill, once-a-day medication for the treatment of most cases of AIDS. The new medication simplifies the daily regimen of medicines.