Alzheimer's Disease

Source: Alzheimer's Association, 225 N Michigan Ave., 17th Fl., Chicago, IL 60601-7633; phone: (800) 272-3900; www.alz.org

Alzheimer's disease, the most common form of dementia, is a progressive, degenerative disease of the brain in which nerve cells deteriorate and die for unknown reasons. Its first symptoms usually involve impaired memory and confusion about recent events. As the disease advances, it results in greater impairment of memory, thinking, behavior, and physical health.

The rate of progression of Alzheimer's varies, ranging from 3 to 20 years; the average length of time from onset of symptoms until death is 8 years. Eventually, affected individuals lose their ability to care for themselves and become susceptible to infections of the lungs, urinary tract, or other organs as they grow progressively debilitated.

Alzheimer's disease affects an estimated 4.5 million Americans, striking men and women of all ethnic groups. Although most people diagnosed with Alzheimer's are older than age 60, some cases occur in people in their 40s and 50s. An estimated 10% of the population over age 65 have Alzheimer's, and the disease affects almost half of those over 85. In the United States, annual costs of diagnosis, treatment, and long-term care are estimated at $100 billion.

Diagnosis involves a comprehensive evaluation that may include a complete health history, a physical examination, neurological and mental status assessments, and other testing as needed. Skilled health care professionals can generally diagnose Alzheimer's with about 90% accuracy. Other conditions that can cause similar symptoms include depression, drug interactions, nutritional imbalances, infections such as AIDS, meningitis, and syphilis, and other forms of dementia, such as those associated with stroke, Huntington's disease, Parkinson's disease, frontotemporal dementia, and vascular disease. Absolute confirmation of diagnosis requires a brain biopsy or autopsy.

Treatments for cognitive and behavioral symptoms are available, but no intervention has yet been developed that prevents Alzheimer's or reverses its course. Some research suggests that risk factors for heart disease, such as high blood pressure, elevated cholesterol, and excess body weight may also increase risk of developing Alzheimer's. Studies also suggest that staying physically and mentally active and socially connected may be associated with a lower risk for the disease.

Providing care for people with Alzheimer's is physically and psychologically demanding. Nearly 70% of affected individuals live at home, where family or friends care for them. In advanced stages of the disease, many individuals require care in a nursing home. Nearly half of all nursing home residents in the U.S. have Alzheimer's.

People with Alzheimer's need a safe, stable environment and a regular daily schedule offering appropriate stimulation. Physical exercise and social interaction are important, as is proper nutrition. Security is also a consideration, because many people with Alzheimer's tend to wander. An identification bracelet listing the person's name, address, and condition may help ensure the safe return of an individual who wanders.
Warning Signs of Alzheimer's Disease

Forgetting recently learned information or inability to learn new information
Difficulty with everyday tasks such as cooking or dressing
Inability to remember simple words
Use of inappropriate words when communicating
Disorientation of time and place
Poor or decreased judgment
Problems with abstract thinking
Putting objects in inappropriate places
Rapid changes in mood or behavior
Increased irritability, anxiety, depression, confusion, and restlessness
Prolonged loss of initiative



Acquired Immune Deficiency Syndrome

Source: Centers for Disease Control and Prevention; www.cdc.gov

AIDS (Acquired Immune Deficiency Syndrome) is caused by the human immunodeficiency virus (HIV). HIV kills or disables crucial cells of the immune system, progressively destroying the body's ability to fight disease.

HIV is commonly spread through unprotected sexual contact with an infected partner. It is also spread through contact with infected blood. Where modern screening techniques are used it is rare to contract HIV from transfusion, but it can be contracted when intravenous drug users share syringes with others. Though HIV can be spread through semen, vaginal fluids, and breast milk, there is no evidence it can be spread through saliva. The rate of transmission from a pregnant woman to her infant is about 25% without treatment, but can be reduced to less than 2% with treatment. Studies have indicated no evidence of HIV transmission through casual contact such as the sharing of food utensils, towels and bedding, telephones, or toilet seats.

Some people experience flu-like symptoms a short time after infection with HIV, and scientists estimate that about half of those infected with HIV develop more serious, often chronic symptoms within ten years. Even when symptoms are not present, HIV is active in the body, multiplying, infecting, and killing CD4+ T cells, or "T-helper cells," the crucial immune cells that signal other cells in the immune system to perform their functions.

The term AIDS applies to the most advanced stages of HIV infection. According to the official definition set by the Centers for Disease Control and Prevention (CDC), an HIV-infected person with fewer than 200 CD4+ T cells can be said to have AIDS. (Healthy adults usually have 1,000 or more). An HIV-infected person, regardless of T cell count, is diagnosed with AIDS if he or she develops one of 26 conditions that typically affect people with advanced HIV. Most of these conditions are "opportunistic infections" that occur when the immune system is so ravaged by HIV that the body cannot fight off certain bacteria, viruses and microbes.

Months or years prior to the onset of AIDS, many people experience such symptoms as swollen glands, lack of energy, fevers and sweats, and skin rashes. People with full-blown AIDS may develop infections of the intestinal tract, lungs, brain, eyes, and other organs, with a variety of symptoms, and may become severely debilitated. They also are prone to developing certain cancers, especially those caused by viruses, such as Kaposi's sarcoma, cervical cancer, and lymphoma. Children with AIDS may have delayed development or failure to thrive.

HIV is primarily detected by testing a person's blood for the presence of antibodies (disease-fighting proteins) to HIV. In about 5% of infected individuals, HIV antibodies may take more than 6 months after exposure to reach detectable levels, but in most cases the antibodies are detectable in about 6 weeks. HIV testing may also be performed on oral fluid and urine samples. New rapid HIV tests can provide preliminary results in about 20 minutes.

The U.S. Food and Drug Administration has approved a number of drugs that may slow down the growth of HIV in the body and treat the infections and cancers associated with AIDS. The first group of drugs used to treat HIV, called nucleoside analog reverse transcriptase inhibitors (NRTIs), include the drug zidovudine (commonly known as AZT). Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have also been approved to treat HIV. A third class of drugs, called protease inhibitors, are also approved for HIV. In 2003 the FDA granted accelerated approval of Fuzeon for use with other anti-HIV drugs to treat advanced cases of infection. Fuzeon was the first among a new class of medications called fusion inhibitors; drugs in this class interfered with HIV's entry into cells by hindering the fusion of viral and cellular membranes.

Patients are typically given a combination of different drugs, because HIV can much more easily become resistant to a single drug. While these drugs extend the period between HIV infection and serious illness, they do not prevent the spread of the disease to others, and can have severe side effects.

Since there is no vaccine or cure for AIDS, the only protection is to avoid activities that carry a risk. When it cannot be known with certainty whether a sexual partner has HIV, the CDC recommends abstinence (the only certain protection), mutual monogamy with an uninfected partner, or correct and consistent use of male latex condoms.

