AIDS

What is HIV infection and AIDS?
How does it occur?
What are the symptoms?
How is a test for HIV infection done?
Who is at high risk for HIV infection?
How can exposure to HIV be avoided?
Instructions for using latex condoms
ELISA and Western Blot Tests

What is HIV infection and AIDS?

The Human Immuno-deficiency Virus or HIV is the organism that ultimately causes AIDS. Soon after first getting the HIV infection the person has a short, self limiting ‘flue-like disease. This only lasts a few days and is so mild that many persons do not even know it. The virus slowly destroys the ability of the body to resist common communicable diseases. When tha resistance of the body is so reduced that infections can no longer be resisted, the person is said to have AIDS. The mean period between getting the HIV infection and developing AIDS is 9.8 years. In other words, in 9.8 years half the HIV infected persons can be expected to develop AIDS and conversely it must be emphasized that half the persons will still be well and healthy at this time.

Once a person has lost the ability to resist common infections and has developed AIDS, the prognosis is poor and death usually comes in 12 to 18 months unless anti-retroviral treatment is initiated. On anti-retrovirals a person can be expected to be sustained for long time. The infection is not cured and treatment must continue life-long.


It must be stressed again that in the early stages of HIV infection, the person feels well and is able to function normally. Examination by a doctor will not reveal any illness and the only detected abnormality is a positive blood test. Such persons should be encouraged to live normally and continue their normal occupation.

AIDS is a serious illness caused by infection with the human immunodeficiency virus (HIV). HIV breaks down the body's immune system, so the person with AIDS can no longer fight off disease successfully. As a result, secondary infections, cancer can more easily take root in the body.

It takes from 6 weeks to several months for the body to form sufficient antibodies (proteins produced in response to infection to show a positive test). When these antibodies can be detected in the blood, the patient is said to be HIV-positive. AIDS is a much later stage when the ability to fight off serious infections is lost.

How does it occur?

HIV is spread by unprotected penetrative sexual contact with an infected person. It can also be acquired when infected blood enters the persons’ blood by sharing needles or the transfusion of infected blood and organ transplants. Infection can also be transmitted from an infected mother to her child in the uterus, during delivery or while breastfeeding.

The virus is also found in smaller amounts in tears, saliva, brain, spinal fluid, urine, and faeces although contact with these bodily fluids is not likely to transmit the virus. Casual contact such as by shaking hands, social kisses, touching an infected person, touching something that the person has handled, using public toilets or telephones, or using swimming pools does NOT spread HIV. The available information also bears out that HIV is not spread by mosquito or other insect bites.

What are the symptoms?

The symptoms of AIDS are the symptoms of the diseases that attack the body because of a weakened immune system. One should never, therefore, attempt to diagnose HIV infection on the basis of symptom or signs only. Patients with HIV/AIDS may present with a variety of manifestations which include:

 



It is important to always keep in mind that all the above symptoms are non-specific and commonly occur in a variety of conditions. To establish a diagnosis of HIV/AIDS a blood test that has been confirmed is essential. A physical examination and other tests are necessary to rule out other illnesses.


How is a test for HIV infection done?

Most of the blood tests used to detect HIV infection work by detecting the presence of HIV antibodies. Keep in mind that early in infection there may not be sufficient antibodies present in the blood to give a positive reaction even though the person has HIV infection. This period is known as the “Window Period” and is dangerous as though the person has a negative test, infection can be spread through sex or blood.
The commonest test used is the ELISA test. The result of a single ELISA (or Rapid / Spot tests) should never be taken to indicate infection but merely as an indication for repeated tests to confirm the result. The WHO recommends that ERS (ELISA, Rapid or Spot) always be repeated to confirm the diagnosis, preferably using a different make of test kit. The Western Blot test is no longer recommended as a mandatory confirmatory test. A single positive test does not indicate infection and must always be confirmed. A negative test does not guarantee that a person is not infected where the risk exposure has occurred recently. If the person has only recently been infected, the antibodies may not yet have been formed (window phase). It may take up to 3 to even 6 months for someone to develop adequate antibodies after exposure to the virus. A confirmed positive test indicates that the person has been exposed to the virus and has developed antibodies but may not necessarily progress to full-blown AIDS.

Who is at high risk for HIV infection?


How can exposure to HIV be avoided?

The best way of self-protection is to learn as much as possible about HIV infection, avoid risky behaviour, and follow guidelines for protection. Abstinence, non-penetrative sex or a stable relationship between mutually faithful partners is optimal. Where this is not possible, risk can be substantially reduced by the following:



At this time, there is no cure or vaccination that will prevent HIV infection, though a lot of research is being done for a vaccine. Anyone engaging in high-risk behaviour should contact a physician to arrange for a complete physical examination and blood tests.

Instructions for using latex condoms:




ELISA and Western Blot Tests

The most common test for AIDS is the ELISA (Enzyme-Linked Immuno-Sorbent Assay), which is performed on a blood sample. This test is very sensitive and detects almost all persons infected with the human immunodeficiency virus (HIV) except during the first few weeks of infection. The ELISA test detects the body's immune response to HIV.

Single tests must not be used to diagnose HIV infection. False positive test results are not infrequent with the ELIA and similar tests. Before making a diagnosis that a specimen is HIV positive, the test result must be confirmed by one or even two repeat tests, even on the same specimen if sufficient sample is available. The confirmatory repeat tests can be ELISA or Rapid / Spot tests. It is preferable to use test kits that are different when doing a confirmatory tests. Confirmation by the Western Blot test is no longer the recommended procedure.

Anyone with a positive test for HIV infection should seek follow-up medical evaluation, interpretation of the results, counselling, and advice for possible lifestyle changes. A negative HIV antibody test implies either the person has not been infected with the HIV virus or does not have a detectable level of HIV antibodies. If the results of the same test done six months later are still negative for HIV antibodies, AIDS infection is highly unlikely, assuming there have been no high-risk activities in those six months.