HIV/AIDS

DEFINITION

AIDS (acquired immunodeficiency syndrome) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body’s ability to fight the organisms that cause disease.

HIV is a sexually transmitted infection. It can also be spread by contact with infected blood or from mother to child during pregnancy, childbirth or breast-feeding. It can take years before HIV weakens your immune system to the point that you have AIDS.

There’s no cure for HIV/AIDS, but there are medications that can dramatically slow disease progression. These drugs have reduced AIDS deaths in many developed nations. But HIV continues to decimate populations in Africa, Haiti and parts of Asia.

CAUSES

Scientists believe a virus similar to HIV first occurred in some populations of chimps and monkeys in Africa, where they’re hunted for food. Contact with an infected monkey’s blood during butchering or cooking may have allowed the virus to cross into humans and become HIV.

How does HIV become AIDS?

HIV destroys CD4 cells — a specific type of white blood cell that plays a large role in helping your body fight disease. Your immune system weakens as more CD4 cells are killed. You can have an HIV infection for years before it progresses to AIDS.

People infected with HIV progress to AIDS when their CD4 count falls below 200 or they experience an AIDS-defining complication, such as:

• Pneumocystis pneumonia
• Cytomegalovirus
• Tuberculosis
• Toxoplasmosis
• Cryptosporidiosis

How HIV is transmitted

To become infected with HIV, infected blood, semen or vaginal secretions must enter your body. You can’t become infected through ordinary contact — hugging, kissing, dancing or shaking hands — with someone who has HIV or AIDS. HIV can’t be transmitted through the air, water or via insect bites.

You can become infected with HIV in several ways, including:

• By having sex. You may become infected if you have vaginal, anal or oral sex with an infected partner whose blood, semen or vaginal secretions enter your body. The virus can enter your body through mouth sores or small tears that sometimes develop in the rectum or vagina during sexual activity.
• From blood transfusions. In some cases, the virus may be transmitted through blood transfusions. American hospitals and blood banks now screen the blood supply for HIV antibodies, so this risk is very small.
• By sharing needles. HIV can be transmitted through needles and syringes contaminated with infected blood. Sharing intravenous drug paraphernalia puts you at high risk of HIV and other infectious diseases, such as hepatitis.
• During pregnancy or delivery or through breast-feeding. Infected mothers can infect their babies. But receiving treatment for HIV infection during pregnancy, mothers significantly lower the risk to their babies.

SYMPTOMS

The symptoms of HIV and AIDS vary, depending on the phase of infection.

Primary infection

The majority of people infected by HIV develop a flu-like illness within a month or two after the virus enters the body. This illness, known as primary or acute HIV infection, may last for a few weeks. Possible signs and symptoms include:

• Fever
• Headache
• Muscle aches
• Rash
• Chills
• Sore throat
• Mouth or genital ulcers
• Swollen lymph glands, mainly on the neck
• Joint pain
• Night sweats
• Diarrhea

Although the symptoms of primary HIV infection may be mild enough to go unnoticed, the amount of virus in the bloodstream (viral load) is particularly high at this time. As a result, HIV infection spreads more efficiently during primary infection than during the next stage of infection.

Clinical latent infection

In some people, persistent swelling of lymph nodes occurs during clinical latent HIV. Otherwise, there are no specific signs and symptoms. HIV remains in the body, however, and in infected white blood cells.

Clinical latent infection typically lasts eight to 10 years. A few people stay in this stage even longer, but others progress to more severe disease much sooner.

Early symptomatic HIV infection

As the virus continues to multiply and destroy immune cells, you may develop mild infections or chronic signs and symptoms such as:

• Fever
• Fatigue
• Swollen lymph nodes — often one of the first signs of HIV infection
• Diarrhea
• Weight loss
• Cough
• Shortness of breath

Progression to AIDS

If you receive no treatment for your HIV infection, the disease typically progresses to AIDS in about 10 years. By the time AIDS develops, your immune system has been severely damaged, making you susceptible to opportunistic infections — diseases that wouldn’t trouble a person with a healthy immune system.

The signs and symptoms of some of these infections may include:

• Soaking night sweats
• Shaking chills or fever higher than 100 F (38 C) for several weeks
• Cough
• Shortness of breath
• Chronic diarrhea
• Persistent white spots or unusual lesions on your tongue or in your mouth
• Headaches
• Persistent, unexplained fatigue
• Blurred and distorted vision
• Weight loss
• Skin rashes or bumps

When to see a doctor

If you think you may have been infected with HIV or are at risk of contracting the virus, see a health care provider as soon as possible.