Wednesday, November 12, 2014

Living with HIV – diagnosis, treatment and prevention

The plasma HIV RNA test (a viral load test) is recommended when recent infection is suspected. The test detects the virus in the blood within 9 days of infection; before the body develops detectable antibodies to it. The only way to diagnose HIV is to take a test which looks for signs of the virus in the blood. Presence of the virus in the blood is termed as HIV positive (HIV+). If no signs of the virus are found in the blood, the result is considered negative. It is diagnosed on the basis of positive results from two different HIV tests.

Antibody tests: The antibody tests check for HIV antibodies that the body produces in response to the infection. In most people, antibodies to the virus are not detectable during a window period of 3 to 12 weeks after infection. Hence, a HIV antibody test is not useful during this period. Retesting should be done after three months to confirm the test results. Some of the antibody tests are as follows:

    Rapid HIV antibody test, the most common HIV test, is done using blood, urine or saliva and can produce results within an hour.
    Enzyme-linked immunosorbent assay (ELISA) is an antibody test that is usually the first one used to detect HIV infection. If the result is positive, the test is usually repeated to confirm the diagnosis.
    Western blot test is one of the oldest but most accurate confirmatory antibody tests. It is done to confirm the results of two positive ELISA tests

Polymerase chain reaction (PCR, a viral load test) test finds either the RNA or the DNA of the HIV in white blood cells even if other tests are negative for the virus. The PCR test is very useful to find a very recent infection, screen blood for HIV before donation and in babies born to mothers infected with the virus.

Protein p24, the antigen on HIV that produces an antibody response in the body is produced in excess early in the infection. Antigen p24 tests detect these proteins in the blood. This test is usually not used for general HIV diagnostic purposes.

HIV-infected people may not have any symptoms of disease for eight to ten years or longer (asymptomatic period). Their CD4 (T-cell) count should be watched closely during this time. If they have a CD4 count below 200 and/or if AIDS-related conditions appear, then they are considered to have AIDS.

The two main goals of HIV treatment are:

  -  to prevent the virus from damaging the immune system
  -  to halt or delay the progress of the infection

Antiretroviral (ARV) drugs are used for treating and preventing HIV infection. They stop or interfere with the reproduction of the virus in the body.

HIV therapy includes combinations of drugs. Antiretroviral therapy (ART) consisting of combination of three or more antiretroviral drugs to suppress the virus. ART does not cure HIV infection. It controls replication of the virus thereby strengthening an individual’s immune system to fight off infections. These drugs must be taken at the right time every day. Incorrect or inconsistent therapy can mutate the virus causing resistance to treatment. In such cases, other medication options must be used. The amount of the virus in the blood (viral load) is measured to monitor the efficacy of the treatment. The goal of treatment is to get an undetectable viral load in lab tests.

There is no cure for HIV. But the progression of the virus in the body can be reduced to a near halt with continued adherence to appropriate antiretroviral therapy. If the infection has progressed to AIDS, treatment may also include drugs to fight and prevent the opportunistic infections. People with HIV need counselling and psychosocial support in addition to antiretroviral treatment. A high quality of life needs to be maintained with basic hygiene, adequate nutrition and safe water.

Can treatment prevent HIV from advancing to AIDS? Treatment with anti-HIV medications prevents the virus from multiplying and destroying the immune system, thus helping the body fight off infections and cancers and preventing HIV from advancing to AIDS.

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