HIV: commonly asked questions

National HIV Testing Week begins on Saturday 17th November 2018 and World AIDS Day on December 1st, so now is the best time to look over some of the most commonly asked questions about HIV (human immunodeficiency virus) testing and treatment!

How soon can HIV be detected by a blood test after contracting the virus?

Generally, it is one month after exposure to HIV that the virus is easily detectable in the blood. Tests done less than one month after exposure are considered unreliable. (1)

What is the window period for HIV testing?

The window period is the one-to-three month time frame following possible exposure to HIV, depending which test you use. The window period for the lab test is 28 days but is 90 days for the “Home” test. If you test before the recommended time frames then the HIV test may need to be repeated. This applies whether an earlier test came back positive or negative, as results from tests conducted earlier than the recommended “window period” for HIV can be unreliable, as previously mentioned. (1)

However, you shouldn’t wait until you may be in the window period before seeking medical help - you should do this as soon as you can if you believe you may have come into contact with HIV. Within the first 72 hours after suspected exposure, a type of medication called post-exposure prophylaxis (PEP) can be taken, which may prevent the infection from taking hold altogether. (1)

Can you receive instant results from an HIV Test?

Tests which provide instant results are available to use. Some genitourinary medicine (GUM) clinics and sexual health clinics offer finger prick testing, and home testing kits can be purchased from some online or high street pharmacies. (1)

How can I test for HIV at home?

There are a number of tests available from Webmed Pharmacy which allow you to test or take a sample in the comfort of your own home.

How accurate are HIV Tests?

• The latest 5th generation HIV lab test kit is 99.8% effective at detecting HIV at least 28 days after potential exposure. It contains a sterile lancet and a test tube. A blood sample is collected by pricking the little finger with the lancet and massaging a small amount of blood into the tube. This is then sealed (further instructions are found in the kit) and sent off to a lab for testing using the pre-paid envelope included. Results should be available two to three days after the sample is received by the lab – you will be able to access these via your secure account.

• The 3rd generation INSTI HIV Home self test allows you to sample and test for HIV yourself, all within just 60 seconds. It is only reliable if used at least 90 days after potential exposure. Like the lab test, blood is collected by pricking the finger (full instructions supplied in the kit). The result is clearly shown as one dot for HIV negative, two dots for HIV positive. Negative results are at least 99.5% accurate and positive results are at least 99.8% accurate.

• The PrEP annual test kit can be used if you are taking pre-exposure prophylaxis (PrEP) – this medicine is used by HIV negative people to prevent infection with HIV. This test can be performed yearly to check HIV status and also kidney function, which can be affected by taking PrEP.

• The pre-treatment PrEP test kit is suitable if you are thinking of starting PrEP. It checks your HIV status, kidney function and also whether you have hepatitis B.

What should I do if I test positive for HIV?

If you get a positive result, seek medical help. You will need to have regular blood tests to monitor the levels of a type of cell called CD4 lymphocytes. CD4 lymphocytes are one of the types of cells that make up the immune system and are also the cells that are targeted by HIV. HIV particles ‘hijack’ the CD4 lymphocytes, replicate themselves within the cells, and are then released in greater numbers when the cell dies, going on to infect further cells. You will need to start treatment to keep your CD4 levels high enough to keep you in good health - if someone with HIV does not start treatment, their CD4 levels will eventually fall so low that they will be at risk of serious infections such as flu, pneumonia and tuberculosis, which their immune system will not be able to cope with (this is known as AIDS  - see below). (2)

Even if your CD4 levels are high, you will still need to start medication to limit the progression of the disease. The aim of treatment is to achieve an undetectable viral load (levels of HIV in the blood being so low that they do not show up on blood tests).

What medications are available for HIV?

There is a wide range of HIV medications available, which are grouped into the following categories:

Other HIV medications outside these categories include enfuvirtide and maraviroc, which work in different ways to the medications listed above. (3)

Taking HIV treatment correctly should allow you to stay in good health, free from symptoms and to achieve a normal lifespan.

What is the difference between HIV and AIDS?

We often hear the abbreviations ‘HIV’ and ‘AIDS’ used interchangeably, but they are not the same! AIDS, or acquired immunodeficiency syndrome, is the most severe stage of HIV. It is characterised by CD4 levels falling so low that the body is very susceptible to opportunistic infections and cancers. Without treatment, AIDS will lead to death, usually within around three years. Fortunately, it is rare in the present day for people in the UK with HIV to progress to AIDS thanks to the thorough prevention, testing, monitoring and treatment strategies. (4)

References

1. NHS Choices. HIV and AIDS: Diagnosis [cited 16 Nov. 18] Available at: https://www.nhs.uk/conditions/hiv-and-aids/diagnosis/

2. NAM Aidsmap. Factsheet CD4 cell counts [cited 16 Nov. 18] Available at: https://www.aidsmap.com/

3. British National Formulary (version 2.1.6) [Mobile application software]. Retrieved from: www.bnf.org

4. CDC. What is HIV? [cited 16 Nov. 18] Available at: https://www.cdc.gov/hiv/basics/whatishiv.html

   Author: Gabby Gallagher MPharm

   Medically reviewed by: Superintendent pharmacist Margaret Hudson BSc(Hons)MRPharmS 28/11/18