Acute HIV infection is caused by the human immunodeficiency virus (HIV), a virus that gradually destroys the immune system.

Primary HIV infection; HIV seroconversion syndrome; Acute retroviral syndrome; HIV infection - acute

Primary or acute HIV infection occurs 2 - 4 weeks after infection with the human immunodeficiency virus (HIV). The virus is spread by:

• Sexual contact
• Contaminated blood transfusions and blood products
• Injection drug use with contaminated needles and syringes
• Passing through the placenta from an infected, pregnant mother to the unborn baby
• Breastfeeding (rarely)

After someone is infected with HIV, blood tests can detect antibodies to the virus, even if they never had any symptoms of their infection. This is called HIV seroconversion (converting from HIV negative to HIV positive by blood testing), and usually occurs within 3 months of exposure, but on rare occasions can by delayed up to a year after infection.

Following the initial infection, there may be no further evidence of illness for the next 10 years. This stage is called asymptomatic HIV infection.

Acute HIV infection can, but does not always, progress to early symptomatic HIV infection and to advanced HIV disease (AIDS). However, the vast majority of patients do ultimately progress to AIDS. To date there are a small number of people who have tested positive for HIV, but later no longer test positive and have no signs of disease. Although this is relatively rare, it provides evidence that the human body may be capable of removing the disease. These people are being carefully watched and studied.

HIV has spread throughout the world. Higher numbers of people with the disease are found in large metropolitan centers, inner cities, and among certain populations with high-risk behaviors.

Note: At the time of diagnosis with HIV, many people have not experienced any symptoms.

Acute HIV infection can appear like infectious mononucleosis, flu, or other viral illnesses. If symptoms occur, they are usually seen 1 - 4 weeks after becoming infected.

Any of the following symptoms can occur:

• Decreased appetite
• Fatigue
• Fever
• Headache
• Malaise
• Muscle stiffness or aching
• Rash
• Sore throat
• Swollen lymph glands
• Ulcers of the mouth and esophagus

These symptoms can last from a few days to 4 weeks, and then subside.

HIV ELISA/Western blot test is usually negative or undetermined during the acute infection and will become positive over the next 3 months.

HIV RNA test ("viral load") is positive in patients with acute HIV infection.

Lower-than-normal CD4 (white blood cell) count may be a sign of a suppressed immune system. The CD4 count usually improves 1 - 2 months after acute infection.

White blood cell differential may show abnormalities.

People with HIV infection need to be educated about the disease and its treatment so they can be active partners in making decisions with their health care provider.

There is still controversy about whether aggressive early treatment of HIV infection with anti-HIV medications (also called antiretroviral medications) will slow the long term progression of disease. You should discuss this option with your health care provider.

Follow these healthy practices in the early stages of HIV infection:

• Avoid exposure to people with infectious illnesses.
• Avoid settings and situations that could lead to depression. Maintain positive social contacts, hobbies, interests, and pets.
• Eat a nutritious diet with enough calories.
• Get enough exercise, but don't wear yourself out.
• Keep stress to a minimum.
• Practice safer sex. The disease is highly transmissible, especially in the first months after infection.

You can often reduce the stress of illness by joining a support group where members share common experiences and problems. See AIDS - support group.

There is no cure for HIV infection or AIDS. However, appropriate treatment can dramatically improve the length and quality of life for persons infected with HIV, and can delay the onset of AIDS.

The treatments for conditions that occur with early symptomatic HIV disease vary in effectiveness. Some infections and diseases are easier than others to treat with medications.

• AIDS (acquired immunodeficiency syndrome)
• Autoimmune diseases
• Cancers, typically Kaposi's sarcoma and lymphomas

Call for an appointment with your health care provider if you have had a possible or actual exposure to AIDS or HIV infection, or if you are at risk and have had symptoms like those of acute HIV infection.

For a comprehensive discussion, see the prevention section in AIDS.

Safer sex behaviors may reduce the risk of getting the infection. There is still a risk of getting infected with HIV, even if you practice "safe sex," because condoms can break. Abstinence is the only sure way to prevent sexual transmission of the HIV virus.

General guidelines:

• Do not have unprotected sexual intercourse with numerous partners or anyone who has multiple partners, uses IV drugs, or that has or may be infected with AIDS.
• Avoid injection drug use. If you do use such drugs, do not share needles or syringes.
• People with AIDS or who have had positive HIV antibody tests can pass the disease on to others and should not donate blood, plasma, body organs, or sperm. Do not exchange body fluids during sexual activity.

People who are at risk for HIV infection should have regular testing to ensure early diagnosis and prompt treatment.

Masur H, Healey L, Hadigan C. Treatment of human immunodeficiency virus infection and acquired immunodeficiency syndrome. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 412.

Sax PE, Walker BD. Immunopathogenesis of human immunodeficiency infection. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 408.