Tropical Diseases - Aids
First reported widely in 1981, AIDS has become a priority of the U.S. Public Health Service. Researchers have isolated a virus, the human immunodeficiency virus ( HIV ), that they believe causes AIDS. This virus was initially called the human T-cell leukemia virus III ( HTLV-III ). Persons with AIDS (PWAs) are susceptible to a variety of unusual or rare illnesses called opportunistic diseases . These include Pneumocystis carinii pneumonia (PCP); Kaposi's sarcoma; thrush, or Candida albicans; dementia (AIDS dementia complex or ADC); herpes simplex; and meningitis.
Groups at highest risk of contracting AIDS include homo- and bisexual men and intravenous drug users in large cities; hemophiliacs; female prostitutes; heterosexuals with multiple partners in areas where AIDS is common; and recipients of multiple blood transfusions from areas where the disease was common between 1983 and 1985. Evidence suggests that the HIV virus may also be affecting more and more young people, particularly runaways. In “passive transmission,” a mother can pass AIDS to her child before or during birth.
Increasingly, medical authorities view AIDS as a disease with which victims may live for years. But AIDS is incurable. No treatment has successfully restored the immune system of an AIDS patient to normal functioning.
Once infection with AIDS occurs, the human body may take from six weeks to a year or more to produce antibodies. These appear in response to the virus's invasion of the blood stream. The symptoms that can follow may resemble those of flu or even the common cold. Symptoms may include swollen glands, or enlarged lymph nodes, in the neck, armpits, or groin; night sweats; fever; unexplained rapid weight loss; chronic, unexplained diarrhea; fatigue; loss of appetite, and bruising and bleeding that do not heal.
To prevent the spread of AIDS, the U.S. Public Health Service has recommended that persons at risk of contracting the disease should:
- • Not donate blood or plasma, sperm, body organs, or other tissues
- • Limit sexual contacts and be assertive with sexual partners about engaging only in safe sexual practices, which include the use of latex condoms and spermicides
- • Not engage in sexual acts in which exchange of body fluids, including semen, takes place
- • Refrain from sharing toothbrushes, razors, or other implements that could be contaminated with blood
- • If a drug user, limit drug use, do not let others use needles you have used, and do not leave needles or other drug paraphernalia where others might find and use them
- • Avoid or postpone pregnancy if testing positive for antibodies to AIDS, or a sexual partner of a man with a positive antibody test.
The Public Health Service has reported that no evidence indicates that the AIDS virus can be transmitted through casual kissing or other social contacts. But persons who have had positive antibody tests should let their physicians and dentists know about the test results. There has been no risk of contracting AIDS through blood donations or transfusions since the introduction of blood-screening procedures in 1985.
Testing and Treatment
A blood test called the ELISA (enzyme-linked immunosorbent assay) test has been developed to detect the presence of antibodies to the AIDS virus in human blood. The test has helped to eliminate nearly all questionable blood and plasma from the nation's blood supply—not to diagnose individuals. Laboratories have also used the Western Blot test to verify positive results from ELISA The HIVAG-1 test is the first designed to help physicians detect the AIDS virus and to monitor its development in the human body. Already in use, a rapid screening test, the Re-combigen HIV-1 Latex Agglutination test, can detect AIDS virus antibodies in five minutes. There are also home test kits available.
In recent years AIDS has been successfully treated with a new class of drugs called protease inhibitors, which are used in combination with the nucleoside analogs AZT, dd1, ddC, d4T, and 3TC. Protease inhibitors are indinavir, nelfinavir, ritona-vir, and saquinavir and others are being developed. This new treatment does not work for everyone, and the drugs are very expensive and have serious side-effects; however, in many patients the treatment reduces the presence of HIV in the blood to almost undetectable levels. Despite the success of this treatment, it is the conclusion of most researchers that the HIV virus can not be completely eradicated once a person has been infected.
Other drugs used to treat AIDS-related diseases include nevaripine, alpha-interferon, focarnet and ganciclor, and aerosolized pentamidine/ and neutrexin.