AIDS

Acquired immunodeficiency syndrome (AIDS) is a condition resulting from an infection with the human immunodeficiency virus (HIV).


General information
HIV attacks and weakens the immune system, which defends the body from infection. After being infected with HIV, the ability to resist infections and certain types of cancer is gradually lost. Eventually, life-threatening infections and cancers develop. Although there's no cure for AIDS, early detection and the use of certain medications can help an infected person stay healthier for a long time.

Causes/associated factors
HIV is present in the body fluids of an infected person. After being infected with HIV, there may be a brief flu-like illness, followed by a period of apparent health. During this time, the person is considered HIV-positive. The diagnosis of AIDS is made later, when certain infections, cancers or signs of immune system weakness develop.
Today, an estimated 1 million Americans are either HIV-positive or have AIDS. Worldwide, more than 36 million people are thought to be affected by HIV or AIDS. A small number of people infected with HIV remain free of AIDS more than 10 years after the initial infection. Researchers continue to study what makes them unique.

HIV and AIDS are most common among the following groups:

men who have sex with men
injection drug users who share needles
people who have multiple sexual partners
people who received blood products between 1977 and April 1985
people who have sex with anyone in the groups listed above
babies born to mothers who are infected with HIV

Transmission
Anyone who's HIV-positive or has AIDS can spread the virus to others. Soon after becoming infected, you become contagious for life -- even when you have no symptoms of infection.
Blood, semen, breast milk and vaginal secretions all contain enough of the virus to spread the disease. Urine, saliva, respiratory secretions and tears may also carry the virus, but not in quantities large enough to cause infection.

Rarely, HIV has appeared to spread through a human bite. However, most bites that could potentially transmit HIV don't result in an HIV infection.

Other body fluids withdrawn from a body cavity -- such as a joint, the abdomen or the spinal column -- may also be contaminated, but these fluids have never been documented to spread HIV. Any body fluid that contains visible blood, such as saliva during dental work, however, is capable of spreading HIV.

The virus can enter the body through mucous membranes, such as those lining the eyes, nose, mouth, genitals or rectum. Any break in the skin may also allow HIV to enter the body, as may occur with contaminated needles or other sharp instruments. This rule also applies to contaminated instruments used to pierce the skin for tattooing, body piercing or acupuncture. According to recommendations from the Centers for Disease Control and Prevention (CDC), such instruments should be used only once and thrown away properly or be sterilized between uses.

HIV can also spread through:

sexual contact (The virus can enter the body through the lining of the vagina, vulva, penis, rectum or mouth.)
sharing needles contaminated with HIV, most common with people who use injection drugs
accidental sticks from contaminated needles or other sharp instruments, most common in medical settings
When a woman who has HIV becomes pregnant, the virus can spread to her unborn child in the womb, during childbirth or through breast milk. The presence of other sexually transmitted diseases increases the risk of HIV entering the body during genital sexual contact or childbirth. Mothers who are HIV-positive should not breastfeed their children.

The screening and treatment of donated blood and blood products since 1985 in the United States and other countries have made the risk of acquiring HIV from contaminated blood and blood products very minor. This may not be the case in developing countries where the financial resources for screening are inadequate, however.

HIV doesn't spread through ordinary contact that doesn't involve body fluids, such as routine social or community contact. Because the virus can't survive outside the body for long, you can't pick up the virus from inanimate objects, such as toilet seats or doorknobs. When fluids infected with HIV dry, there's considered to be no risk of infection.


Signs/symptoms
Within a month or two of being infected with HIV, some people develop mild symptoms that last a week or two, such as fever, headache, fatigue, enlarged lymph nodes, sore throat or rash. Even people who have no symptoms with the initial infection are still highly contagious.
Next comes a period when no symptoms are present. For adults, this symptom-free period may last from many months to more than a decade. For children born with HIV, the symptom-free period is shorter, possibly lasting up to two years. Although no symptoms are present, the virus is actively multiplying, infecting and weakening the immune system. You remain highly contagious during this silent period.

Eventually, symptoms of the advancing disease develop. The advanced symptoms vary in timing, order of appearance and severity, sometimes appearing before the actual diagnosis of AIDS. They may include:

fever or chills
night sweats
fatigue
appetite loss
weight loss
swollen glands
cough or shortness of breath
persistent diarrhea
memory loss
skin rashes
mouth sores
joint or muscle pain
abdominal pain
for infants and children, failure to grow and develop normally
As the immune system weakens, various cancers and infections known as opportunistic infections may be identified. These include:

candidiasis (a fungal infection caused by Candida albicans) of the airways in the lungs or the lungs themselves, the trachea (windpipe) or the esophagus (the tube that connects the throat and stomach)
shingles, often disseminated (an infection caused by the same virus that causes chickenpox that produces stabbing pain and a rash)
genital or oral herpes
cytomegalovirus infection (CMV, another virus in the herpes family)
Pneumocystis carinii pneumonia (PCP, a type of pneumonia)
tuberculosis (an infectious disease that affects the respiratory system)
toxoplasmosis (a parasitic infection of the brain, eyes, liver and lungs)
cryptosporidiosis (a parasitic infection of the gastrointestinal tract)
histoplasmosis (a fungal infection of the lungs, liver or bone marrow)
cryptococcus (a fungal infection of the brain, liver or bones)
coccidioidomycosis (a fungal infection of the brain, liver, kidneys or bones)
salmonella (a bacterial infection of the gastrointestinal tract)
Kaposi's sarcoma (a rare type of skin cancer)
non-Hodgkin's lymphoma (cancer of the lymphatic system)
invasive cervical cancer
Eventually, AIDS may make it impossible to handle routine tasks or even perform basic personal care. It's not unusual to experience periods of severe or life-threatening illness, followed by periods of relatively good health. Without treatment, the life expectancy for someone diagnosed with AIDS is generally two to three years, but this has greatly improved with developments and progress in treatment.


Diagnosis
A simple blood test is often done to determine whether HIV is present in your system. Specifically, the blood is tested for antibodies (compounds that help neutralize or destroy foreign substances in the blood) to HIV. Sometimes saliva or urine samples are also tested. Most infected people have antibodies in their blood within one to three months after infection, but it may take up to six months for some people. The CDC recommends being tested six months after the last possible exposure. If you're tested sooner and the test is negative, you'll need to be retested at six months.
Home HIV test kits were approved by the U.S. Food and Drug Administration (FDA) in 1996. You simply place a finger-prick blood sample on a test card and mail it to a lab in a protective envelope. The results can be obtained a week later by calling a toll-free number.

Separate blood tests are done for newborns, who may have received HIV antibodies from their HIV-positive mothers even if they're not infected with the virus itself. For newborns, blood tests can typically determine the presence of HIV by age 6 months.

A blood test known as the CD4+T lymphocyte cell count is used to measure the progression of the HIV infection after the diagnosis is made. This count is an indication of the health or status of your immune system. When you're infected with HIV, the virus enters the CD4+T lymphocyte cells and progressively destroys them. Healthy people not infected with HIV have a CD4+T lymphocyte cell count of at least 1,000. Experts at the CDC consider anyone with a count of 200 or below to have AIDS. (The definition of AIDS also includes anyone who has advanced HIV infection and any of the 26 separate clinical conditions as outlined by the CDC, including those listed in the symptoms section above, even if the CD4+T lymphocyte count is above 200.)

Another blood test known as a viral load test may be done to measure the amount of virus in your blood. The results of this test can be used along with the CD4 cell count to help determine and evaluate treatment effectiveness.


Treatment
If you have HIV or AIDS, seek care from a doctor who regularly treats HIV patients. In addition to HIV treatment, remember the importance of general preventive care and treatment for routine medical problems. Avoid any activities that could spread HIV to others.
Medication therapy
When HIV was first identified, no medications were available to fight the virus. Today, intensive research efforts have lead to the development of medications that slow down or prevent HIV from reproducing in the cells of the immune system. Thus, medication therapy can often lengthen life and improve the quality of life for people infected with HIV.

The FDA has approved many medications for the treatment of AIDS in the past few years.

Nucleoside reverse transcriptase inhibitors (nRTIs) work by preventing the virus from reproducing early in its life cycle. Some of the medications in this classification include zidovudine (ZDV or AZT), lamivudine (3TC), stavudine (d4T), Combivir (AZT and 3TC) and didanosine (ddI).

Non-nucleoside reverse transcriptase inhibitors (nnRTIs) also prevent the reproduction of the virus. These include delavirdine, nevirapine and efavirenz.

Protease inhibitors (PIs) prevent the virus from reproducing later in its life cycle. These include ritonavir, nelfinavir, indinavir, amprenavir and saquinavir. Protease inhibitors are the most effective anti-HIV medications available today.

Entry inhibitors (including fusion inhibitors) work by preventing the virus from entering healthy CD4+T lymphocyte cells. Other HIV medications work after the cells have been infected. Only one medication, enfuvirtide (T-20), has been approved by the FDA so far.
No single medication or combination of medications has been able to suppress HIV permanently, but combinations of three or four of these medications can lower viral levels to the point where the virus can't be detected in the blood. These medication combinations, know as highly active antiretroviral therapy (HAART), are now the standard treatment for HIV. The best time to start treatment is still being studied. Resistance of the virus to the anti-HIV medications has become a growing problem, however. To help prevent resistance, it's important to take the medications exactly as prescribed. If you develop side effects, contact your doctor right away rather than changing the medication on your own.

In addition to antiviral medications, your doctor may recommend immunizations to prevent certain infections, such as the flu and pneumonia. You may also be prescribed routine antibiotics to help prevent infections.

Diet
It's important to prevent and treat malnutrition. Your doctor may prescribe medication to treat some of the weight loss that can accompany AIDS, as well as suggest vitamin supplements. If weight loss and diet are a concern, you may want to consult a registered dietitian.

To avoid food-borne infections, avoid eating meat, poultry or fish that hasn't been well cooked or adequately stored to prevent spoiling. Avoid unpasteurized milk and dairy products, as well as any foods containing raw eggs. If you choose to eat eggs, eat only those that have been well cooked. Make sure fresh fruits and vegetables have been thoroughly washed, and peel fruit before eating. Also make sure your water is safe. (Your local health department may be able to assist you with water evaluation.)

Lifestyle
It's important to exercise regularly and get adequate rest and relaxation.


Complications
AIDS often leads to a weak immune system, changes in mental status, certain cancers and frequent infections, some of which can be life-threatening. To avoid or ease depression and social isolation, seek appropriate counseling and support.

Pregnancy-specific information
If you're HIV-positive, seek counseling before conceiving. If you're pregnant and don't know your HIV status, make sure you're tested during the pregnancy. Routine testing is recommended by the CDC and the American College of Obstetricians and Gynecologists, and such testing is now required in some states.
Research has shown the risk of passing HIV to the baby decreases by up to 70 percent in HIV-positive women who take the medication zidovudine (also known as AZT or Retrovir) during pregnancy. The medication is started at 14 weeks and continued until delivery. The baby also receives the medication for the first six weeks after delivery. The use of zidovudine for a shorter period of time can reduce the transmission by up to 40 percent.

Recently, the medication nevirapine has also been found to be effective in preventing HIV transmission to babies. A single dose is given during labor and another is given to the baby after birth. Research continues in this area.


Senior-specific information
Growing older isn't considered a risk factor for HIV infection. As people who have HIV age, however, HIV progresses more rapidly to AIDS.

Prevention
Learning how to prevent the spread of HIV is the best way to protect yourself from AIDS. Avoid direct, unprotected contact with the blood, semen, vaginal secretions and other possibly infected body fluids of a person who has HIV or AIDS. Don't share intravenous needles or have unprotected sex with a person who may be infected with HIV. Also be aware that "protected" sex doesn't offer any guarantees.
Remember that people infected with HIV may appear to be in good health. You may ask any potential sexual partners to be tested for the virus before having sexual contact, but remember the test must be done six months after the last possible exposure to the virus to be accurate. You can't rely on a negative test result if you're not sure if the person has been exposed to the virus within the last six months. It's best to avoid sex with anyone who could be or is infected with HIV. If you choose to have sex, the correct and consistent use of latex or polyurethane condoms for any vaginal, anal or oral sexual contact will reduce the risk of getting or spreading the infection. Use only water-based lubricants with latex condoms to avoid breakdown of the latex by chemicals in other lubricants.

If you're HIV-positive or have AIDS, don't have unprotected sex, share needles, breastfeed, or donate blood, semen, breast milk or any type of bone or tissue. Inform any sexual partners of your HIV status before having sex, and inform your doctor as well.

If you have any risk factors for HIV infection, get tested. Early diagnosis and treatment can help slow the progression of the disease. Knowing your diagnosis will also allow you to take steps to prevent spreading HIV to others. Tests are often available through the local health department, doctor's offices and hospitals. There may be special HIV testing locations, as well as anonymous test sites. You may want to choose a location that also offers HIV and AIDS counseling. Of course, home testing is also available. If you're unsure of how to obtain testing in your area, contact the CDC National AIDS Hotline for further information.