WHAT IS AIDS?

The term AIDS applies to the most advanced stages of HIV infection. CDC developed official criteria for the definition of AIDS and is responsible for tracking the spread of AIDS in the United States.

Symptoms of opportunistic infections common in people with AIDS include
• Coughing and shortness of breath
• Seizures and lack of coordination
• Difficult or painful swallowing
• Mental symptoms such as confusion and forgetfulness
• Severe and persistent diarrhea
• Fever
• Vision loss
• Nausea, abdominal cramps, and vomiting
• Weight loss and extreme fatigue
• Severe headaches
• Coma

Children with AIDS may get the same opportunistic infections as do adults with the disease. In addition, they also have severe forms of the typically common childhood bacterial infections, such as conjunctivitis (pink eye), ear infections, and tonsillitis.
People with AIDS are also particularly prone to developing various cancers, especially those caused by viruses such as Kaposi's sarcoma and cervical cancer, or cancers of the immune system known as lymphomas. These cancers are usually more aggressive and difficult to treat in people with AIDS. Signs of Kaposi's sarcoma in light-skinned people are round brown, reddish, or purple spots that develop in the skin or in the mouth. In dark-skinned people, the spots are more pigmented.

During the course of HIV infection, most people experience a gradual decline in the number of CD4+ T cells, although some may have abrupt and dramatic drops in their CD4+ T-cell counts. A person with CD4+ T cells above 200 may experience some of the early symptoms of HIV disease. Others may have no symptoms even though their CD4+ T-cell count is below 200.
Many people are so debilitated by the symptoms of AIDS that they cannot hold a steady job or do household chores. Other people with AIDS may experience phases of intense life-threatening illness followed by phases in which they function normally.

A small number of people first infected with HIV 10 or more years ago have not developed symptoms of AIDS. Scientists are trying to determine what factors may account for their lack of progression to AIDS, such as
• Whether their immune systems have particular characteristics
• Whether they were infected with a less aggressive strain of the virus
• If their genes may protect them from the effects of HIV
Scientists hope that understanding the body's natural method of controlling infection may lead to ideas for protective HIV vaccines and use of vaccines to prevent the disease from progressing.

DIAGNOSIS

Because early HIV infection often causes no symptoms, your health care provider usually can diagnose it by testing your blood for the presence of antibodies (disease-fighting proteins) to HIV. HIV antibodies generally do not reach noticeable levels in the blood for 1 to 3 months following infection. It may take the antibodies as long as 6 months to be produced in quantities large enough to show up in standard blood tests. Hence, to determine whether you have been recently infected (acute infection), your health care provider can screen you for the presence of HIV genetic material. Direct screening of HIV is extremely critical in order to prevent transmission of HIV from recently infected individuals.

If you have been exposed to the virus, you should get an HIV test as soon as you are likely to develop antibodies to the virus-within 6 weeks to 12 months after possible exposure to the virus. By getting tested early, if infected, you can discuss with your health care provider when you should start treatment to help your immune system combat HIV and help prevent the emergence of certain opportunistic infections (see section on treatment below). Early testing also alerts you to avoid high-risk behaviors that could spread the virus to others.

Most health care providers can do HIV testing and will usually offer you counseling at the same time. Of course, you can be tested anonymously at many sites if you are concerned about confidentiality.

Health care providers diagnose HIV infection by using two different types of antibody tests: ELISA and Western Blot. If you are highly likely to be infected with HIV but have been tested negative for both tests, your health care provider may request additional tests. You also may be told to repeat antibody testing at a later date, when antibodies to HIV are more likely to have developed.

Babies born to mothers infected with HIV may or may not be infected with the virus, but all carry their mothers' antibodies to HIV for several months. If these babies lack symptoms, a doctor cannot make a definitive diagnosis of HIV infection using standard antibody. Health care providers are using new technologies to detect HIV to more accurately determine HIV infection in infants between ages 3 months and 15 months. They are evaluating a number of blood tests to determine which ones are best for diagnosing HIV infection in babies younger than 3 months.

TREATMENT

When AIDS first surfaced in the United States, there were no medicines to combat the underlying immune deficiency and few treatments existed for the opportunistic diseases that resulted. Researchers, however, have developed drugs to fight both HIV infection and its associated infections and cancers.

HIV infection

The Food and Drug Administration (FDA) has approved a number of drugs for treating HIV infection. The first group of drugs used to treat HIV infection, called nucleoside reverse transcriptase (RT) inhibitors, interrupts an early stage of the virus making copies of itself. These drugs may slow the spread of HIV in the body and delay the start of opportunistic infections. This class of drugs, called nucleoside analogs, include
• AZT (Azidothymidine)
• ddC (zalcitabine)
• ddI (dideoxyinosine)
• d4T (stavudine)
• 3TC (lamivudine)
• Abacavir (ziagen)
• Tenofovir (viread)
• Emtriva (emtricitabine)
Health care providers can prescribe non-nucleoside reverse transcriptase inhibitors (NNRTIs), such as
• Delavridine (Rescriptor)
• Nevirapine (Viramune)
• Efravirenz (Sustiva) (in combination with other antiretroviral drugs)
FDA also has approved a second class of drugs for treating HIV infection. These drugs, called protease inhibitors, interrupt the virus from making copies of itself at a later step in its life cycle. They include
• Ritonavir (Norvir)
• Saquinivir (Invirase)
• Indinavir (Crixivan)
• Amprenivir (Agenerase)
• Nelfinavir (Viracept)
• Lopinavir (Kaletra)
• Atazanavir (Reyataz)
• Fosamprenavir (Lexiva)

FDA also has introduced a third new class of drugs, known at fusion inhibitors, to treat HIV infection. Fuzeon (enfuvirtide or T-20), the first approved fusion inhibitor, works by interfering with HIV-1's ability to enter into cells by blocking the merging of the virus with the cell membranes. This inhibition blocks HIV's ability to enter and infect the human immune cells. Fuzeon is designed for use in combination with other anti-HIV treatment. It reduces the level of HIV infection in the blood and may be active against HIV that has become resistant to current antiviral treatment schedules.

Because HIV can become resistant to any of these drugs, health care providers must use a combination treatment to effectively suppress the virus. When multiple drugs (three or more) are used in combination, it is referred to as highly active antiretroviral therapy, or HAART, and can be used by people who are newly infected with HIV as well as people with AIDS.
Researchers have credited HAART as being a major factor in significantly reducing the number of deaths from AIDS in this country. While HAART is not a cure for AIDS, it has greatly improved the health of many people with AIDS and it reduces the amount of virus circulating in the blood to nearly undetectable levels. Researchers, however, have shown that HIV remains present in hiding places, such as the lymph nodes, brain, testes, and retina of the eye, even in people who have been treated.

Side effects

Despite the beneficial effects of HAART, there are side effects associated with the use of antiviral drugs that can be severe. Some of the nucleoside RT inhibitors may cause a decrease of red or white blood cells, especially when taken in the later stages of the disease. Some may also cause inflammation of the pancreas and painful nerve damage. There have been reports of complications and other severe reactions, including death, to some of the antiretroviral nucleoside analogs when used alone or in combination. Therefore, health care experts recommend that you be routinely seen and followed by your health care provider if you are on antiretroviral therapy.

The most common side effects associated with protease inhibitors include nausea, diarrhea, and other gastrointestinal symptoms. In addition, protease inhibitors can interact with other drugs resulting in serious side effects. Fuzeon may also cause severe allergic reactions such as pneumonia, trouble breathing, chills and fever, skin rash, blood in urine, vomiting, and low blood pressure. Local skin reactions are also possible since it is given as an injection underneath the skin.
If you are taking HIV drugs, you should contact your health care provider immediately if you have any of these symptoms.

Opportunistic infections

A number of available drugs help treat opportunistic infections. These drugs include
• Foscarnet and ganciclovir to treat CMV (cytomegalovirus) eye infections
• Fluconazole to treat yeast and other fungal infections
• TMP/SMX (trimethoprim/sulfamethoxazole) or pentamidine to treat PCP (Pneumocystis carinii pneumonia)

Cancers

Health care providers use radiation, chemotherapy, or injections of alpha interferon-a genetically engineered protein that occurs naturally in the human body-to treat Kaposi's sarcoma or other cancers associated with HIV infection.

PREVENTION

Because no vaccine for HIV is available, the only way to prevent infection by the virus is to avoid behaviors that put you at risk of infection, such as sharing needles and having unprotected sex.
Many people infected with HIV have no symptoms. Therefore, there is no way of knowing with certainty whether your sexual partner is infected unless he or she has repeatedly tested negative for the virus and has not engaged in any risky behavior. You should either abstain from having sex or use male latex condoms or female polyurethane condoms, which may offer partial protection, during oral, anal, or vaginal sex. Only water-based lubricants should be used with male latex condoms.
Although some laboratory evidence shows that spermicides can kill HIV, researchers have not found that these products can prevent you from getting HIV.

RESEARCH

NIAID-supported investigators are conducting an abundance of research on all areas of HIV infection, including developing and testing preventive HIV vaccines and new treatments for HIV infection and AIDS-associated opportunistic infections. Researchers also are investigating exactly how HIV damages the immune system. This research is identifying new and more effective targets for drugs and vaccines. NIAID-supported investigators also continue to trace how the disease progresses in different people.
Scientists are investigating and testing chemical barriers, such as topical microbicides, that people can use in the vagina or in the rectum during sex to prevent HIV transmission. They also are looking at other ways to prevent transmission, such as controlling STIs and modifying personal behavior, as well as ways to prevent transmission from mother to child.

MORE INFORMATION

AIDSinfo is a comprehensive resource for up-to-date information on government and industry sponsored HIV/AIDS treatment and prevention clinical trials. AIDSinfo also maintains the most current, federally approved guidelines for treating and preventing HIV/AIDS in adults and children, for AIDS related illnesses, for managing occupational exposure to HIV and for preventing HIV transmission from mother-to-child during pregnancy.

AIDSinfo is sponsored by the National Institutes of Health (NIH) Office of AIDS Research, NIAID, National Library of Medicine, CDC, Health Resources and Service Administration, and Centers for Medicare and Medicaid Services.

AIDSinfo
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http://aidsinfo.nih.gov

Prepared by:
Office of Communications and Public Liaison
National Institute of Allergy and Infectious Diseases
National Institutes of Health
Bethesda, MD 20892
http://www.niaid.nih.gov/factsheets/hivinf.htm

© 2008 AIDS Support Group of Cape Cod