There are a number of tests that are used to find out whether a person is infected with HIV, the virus that causes AIDS. These include the HIV antibody test, P24 antigen test and PCR test. There are other types of HIV testing, which are used once a person has been diagnosed with the virus. These include the CD4 test (Usually, the CD4 test is used to determine when a person should start treatment. HIV attacks a type of immune system cell called the T-helper cell. The T-helper cell plays an essential part in the immune system by helping to co-ordinate all the other cells to fight illnesses. HIV damages and destroys T-helper cells; as a result, there are fewer cells available to help the immune system. A major reduction in the number of T-helper cells can have a serious effect on the immune system.
A CD4 test measures the number of T-helper cells (in a cubic millimetre of blood) which is known as a CD4 count. Someone who is not infected with HIV normally has between 500 and 1200 cells/mm3. In a person infected with HIV, the CD4 count often declines over a number of years.
HIV drug treatment is generally recommended when the CD4 test shows fewer than 350 cells/mm3. World Health Organization (WHO) 2010 guidelines recommend starting treatment for all patients with CD4 counts of ?350 cells/mm3 in all countries.1 Although most resource-limited countries aim to follow these guidelines, a number still observe the WHO's 2006 guidelines, which recommend starting treatment at less than 200 cells/mm3.
viral load test. Viral load refers to the amount of HIV in the blood. If the viral load is high, T-helper cells tend to be destroyed more quickly. Therefore, the aim of antiretroviral treatment is to keep the viral load as low as possible.
In places where it is available, a viral load test is carried out shortly after antiretroviral treatment is started. If the treatment is working effectively, the viral load will drop to the undetectable level – below 50 copies/ml. Ideally this will happen within 24 weeks of starting treatment, but for some it can take 3 to 6 months. On the other hand, some people never reach undetectable.
Viral load tests are then carried out every few months. As some viral load tests can produce slightly different results on the same sample of blood, the results are monitored over a period of time.
A Rapid Test
These tests are based on the same technology as ELISA tests, but instead of sending the sample to a laboratory to be analysed, the rapid test can produce results within 20 minutes.
Rapid tests can use either a blood sample or oral fluids. They are easy to use and do not require laboratory facilities or highly trained staff.
All positive results from a rapid test must be followed up with a confirmatory test, the results of which can take from a few days to a few weeks.
In addition to an introduction to the different types of test, we also look at the good reasons why it is important to get tested for HIV and what an HIV test involves.
What are the reasons to get tested for HIV?
For people who think they may have been exposed to HIV, having a test and receiving a negative result (which means they are not infected with HIV), can put their mind at rest.
If the HIV test is positive, there are a number of things that can be done to help a person cope with the result and lead a healthy life.
A person who tests positive will at some point need to take antiretroviral treatment to slow down the virus and maintain a healthy immune system. The longer a person remains unaware of their infection, the less likely it is that the treatment will work. Doctors can monitor an HIV positive person’s health in order to provide the right treatment regimen at the right time.
If a person is aware of their HIV infection they can take steps to protect other people. They can practice safer sex(Safe sex’ is any activity through which you are at no risk of becoming infected with HIV or an STD. 'Safer sex' refers to sex in which the risk of becoming infected with HIV or an STD is minimized by use of condoms ). and inform previous sexual partners that they may have been at risk of infection.
Those who test positive who were thinking of starting a family can learn about ways to protect their child from becoming infected with HIV through MTCT(Mother-to-child transmission (MTCT) is when an HIV-infected woman passes the virus to her baby. This can occur during pregnancy, labour and delivery, or breastfeeding. Without treatment, around 15-30 percent of babies born to HIV-infected women will become infected with HIV during pregnancy and delivery. A further 5-20 percent will become infected through breastfeeding.
In and around Luton they are also number of places where people can go to have an HIV rapid Test. CAFPH has in the past carried out a pilot scheme in rapid testing we are also planning to do HIV Rapid Testing again in future.
Community HIV Testing - please contact the following if you need to book for an HIV Test
Blenheim Medical centre
9 Blenheim Crescent
Telephone: 01582 404 012
19 Russell Avenue
Tel: 01727 842532
Text Number: 07800 473 104
Luton and Dunstable Hospital
Gum Clinic - Sexual Health Clinic
Free and confidential HIV testing - same day result - Monday to Thursday - 01582 497070 - www.ldh.nhs.uk