STI / HIV Lab Testing
HIV Testing
It is not uncommon for individuals to be unaware of the fact that they have HIV. In fact, 40% of new HIV infections are transmitted by individuals who are not aware that they have the virus. Testing for HIV is an important first step in maintaining a healthy lifestyle and preventing transmission of HIV.
When should I get tested?
Individuals who are at a higher risk than others should be tested for HIV. The following list includes a number of situations which might put you at a higher risk for HIV.
- If you are a man who has anal sex with other men.
- If you've had sex with someone who tested positive for HIV.
- If you've had more than 1 sexual partner since your last HIV test.
- If you've shared needles with someone else.
- If you've been diagnosed or treated for another STI.
- If you've been diagnosed or treated for hepatitis or tuberculosis.
- If you've had sex with someone who has had numerous partners, suffered from an STI, or shared needles.
If this is the case, you should test yourself for HIV at least once a year. It is of utmost importance to disclose your sexual and drug use history as well as your HIV status with your partner prior to engaging in a sexual relationship.
Why is it important to get tested early?
HIV treatment has been shown to be most effective if started as soon as possible. Treatment for HIV is referred to as antiretroviral therapy (or ART). Treatment with ART may reduce the amount of HIV virus present within the blood, and as a result lowers the likelihood of developing HIV-related illnesses. Individuals who take the HIV medicines regularly have a low amount of HIV virus in their system and as a result have a very low risk of transmitting HIV to others. If you are pregnant and HIV positive, ART may significantly reduce the chances of your baby being born with HIV.
People at risk of HIV who test negative may need to take "Pre-Exposure Prophylaxis". This is a form of treatment which is given to those who think they might come into contact with HIV. People who believe that have already come into contact with someone who is HIV-positive may need to take "Post-Exposure Prophylaxis" in order to prevent contracting HIV.
What tests are available for HIV testing?
Even though HIV tests are highly accurate, there is no HIV test which can detect the virus immediately after infection. There are 3 types of tests which can confirm HIV infection. These include nucleic acid tests, antigen/antibody tests, and antibody tests.
- Nucleic acid tests detect the virus in blood. This is not usually performed unless you are at a high risk of contracting HIV. This test can detect HIV 10-33 days after exposure.
- Antigen/Antibody tests can identify the immune cells which fight against HIV as well as antigens. Antigens are substances which activate your immune system. The antigen "p24" is produced before your immune system has the chance to fight against the disease. This test is carried out using blood testing and can detect HIV 18-45 days after exposure to the virus. There is also a rapid antigen/antibody test which can be carried out by pricking your finger. This rapid test may detect HIV 18-90 days after exposure.
- Antibody tests look for antibodies, which are a protein created by the immune system to detect bacteria, viruses, and harmful substances. This can detect HIV 23-90 days after exposure to the virus.
You can also purchase an HIV self-test kit. The HIV self-testing kit is available for purchase in local pharmacies. The kit gives you the ability to test for HIV at your own home. It requires a drop of blood. The result is available within 15 minutes.
The test has a window period of 3 months from the last sexual encounter. This implies that if you had sex with someone less than 3 months ago, the test is not accurate.
What do I do if I test positive?
If you test positive when using the self-test or the rapid test, you should book an appointment with the GU Clinic in order to confirm the diagnosis by calling 25457494/1.
HIV treatment has advanced so much in the last few years that HIV-positive people are expected to have a normal life expectancy. With prompt treatment with ART, the HIV viral load becomes so low that it becomes very difficult to transmit the disease to others, and the risk of developing AIDS is lowered.
Reference List:
https://www.hivmalta.com/testing
https://www.cdc.gov/hiv/basics/hiv-testing/hiv-self-tests.html
https://www.cdc.gov/hiv/testing/index.html
STI Testing
Many Sexually Transmitted Infections (STIs) do not always show symptoms. Testing is the only way to know for sure if you have an STI. Most STIs can be treated and cured.
When can I test for STIs?
There is no need to delay STI testing, especially if you had casual unprotected sex. However, there is also the 'window period', i.e. the length of time between when a person is exposed to a bacteria or virus and when it will show in a test.
- 2 weeks for Chlamydia and Gonorrhea tests.
- 4 weeks for HIV tests* (Lab tests and 4th Generation rapid tests).
- 12 weeks for Syphilis and Hepatitis B tests.
What are the tests for most common STIs?
Chlamydia
• A vulvovaginal specimen for a Nucleic Acid Amplification Test (NAAT) is the preferred specimen and test for chlamydia for persons with female genital characteristics. Vulvovaginal specimens can be self-taken by the individual being tested.
• Pharyngeal and rectal samples for NAAT should be considered when there is a history of potential exposure at these sites.
• A first catch urine sample for NAAT is the preferred sample and test for persons with male genital characteristics.
• If a test for chlamydia in the rectum is required, it should be submitted for a NAAT test.
• For men who have sex with men (MSM), a first catch urine sample for NAAT is the preferred sample and test.
• A vulvovaginal specimen for Nucleic Acid Amplification Test (NAAT) is now the specimen and test of choice for identification of Gonorrhea in asymptomatic persons with female genital characteristics. Vulvovaginal specimens can be self-taken by the individual being tested.
• Pharyngeal and rectal samples for NAAT should be considered when there is a history of potential exposure at these sites.
• A first catch urine sample for testing by NAAT is the preferred specimen and test for Gonorrhea in asymptomatic persons with male genital characteristics. The positive predictive value of this test will vary according to the prevalence in the population being tested. A positive result should be confirmed by a second swab for culture.
Syphilis
A venous blood sample is required for a syphilis screening test. In most laboratories, this will be a combined IgM and IgG syphilis antibody*.
*There is variation in the screening tests used by different laboratories.
Hepatitis B
A venous blood for sample is taken for a Hepatitis B screening test i.e. EIA for HBsAg. Tests for anti-HBcAb and anti-HBsAb.
Hepatitis C
A venous blood specimen is taken for a Hepatitis C antibody test.
Hepatitis A
A venous blood sample to check for Hepatitis A total antibody should be offered to MSM who are not known to be immune during local outbreaks.
Reference List:
https://www.bashhguidelines.org/media/1208/gc-2019.pdf
https://www.bashhguidelines.org/media/1084/sti-testing-tables-2015-dec-update-4.pdf