Disease and man: AIDS
By Jeanne Smith, Contributor

ACQUIRED IMMUNE Deficiency Syndrome (AIDS)
is caused by the human immunodeficiency virus (HIV).

The disease severely weakens the body's immune system, by binding to the surface of T4 lymphocytes (type of white blood cells, also called T4 cells or helper cells) thus inactivating and destroying them. These T4 cells are an important part of the immune system, the destruction of these cells leaves the body susceptible to a number of opportunistic pathogenic diseases, any of which can cause death.

HIV may be transmitted in several ways; a person becomes infected with the virus, when body fluids from an infected person, enters his or her bloodstream. Persons may get infected:

* during sexual intercourse

* by sharing infected hypodermic needles (usually used by intravenous drug users).

* body fluids of an infected person getting on to cuts or wounds of uninfected persons

* blood transfusions from infected persons.

* prior to birth, the infected mother may transmit the virus to the foetus through the placenta;

* through breast milk (infants).

HIV is NOT spread by casual contact. Activities such as holding hands or embracing an infected person do not transmit the disease; nor is it spread through droplets of moisture from sneezing or coughing.

SYMPTOMS

HIV infection is not AIDS, an infected person may not develop symptoms for several years. Infected persons who do not develop symptoms are called carriers. The virus, or an antibody against the virus may be detected in the blood between six weeks to years after being infected.

Common symptoms include swollen lymph nodes, a persistent cough, fatigue, prolonged fever, loss of appetite, chronic diarrhoea and rashes on the skin; antibodies may also be detected in the blood.

The progressive destruction of the immune system results in AIDS. A number of opportunistic diseases may appear. These include tuberculosis, lymphoma, a rare type of pneumonia and kaposis sarcoma (a type of skin cancer).

Treatment and control

There is no known cure for AIDS, however the disease may be controlled by controlling the spread of the virus. Controlling the spread of the virus may be achieved by:

1. Practising good sexual habits such as:

* abstinence
* having one safe partner
* using condoms during sexual intercourse.

2. Testing donated blood for the presence of antibodies against HIV.

3. Testing pregnant women for antibodies and treating these persons in order to reduce the risk of infecting the baby; testing new born babies for antibodies and encouraging infected mothers not to breast feed.

4. Observing proper safety precautions when administering health care, for example wearing gloves and coats.

5. Using clean hypodermic needles and syringes.

6. Not taking drugs intravenously.

7. Tracing, testing and possibly treating sexual contacts of infected persons.

8. Public education to increase awareness about the methods through which HIV is spread and how to avoid getting the virus. Education may also prevent
social problems such as neglect or job loss.

Infected persons suffering with AIDS may be treated with drugs which may prevent many opportunistic diseases, enhance the immune system or treat the
symptoms of these opportunistic infections.

There are several social implications of AIDS. Persons with AIDS pressure the health services, the drugs used to treat AIDS are very costly. Victims are likely to suffer job loss or be neglected by family and friends. Some persons with the disease may be constantly ill, this reduces productivity. Victims also have shortened life expectancies.

*Jeanne Smith teaches Biology at the Queen's school. Send your questions and comments to the CXC Study Guide, the Gleaner Company Ltd., 7 North Street, Kingston; or email us at jcampbell@gleanerjm.com