What other tests do I need?

2 November 2023. Related: HIV positive people, Resources.

After you test HIV positive, your doctor will run a few other tests.

HIV test for recent infection (RITA, STARHS)

In the UK, another type of HIV test can help know whether this is a recent infection (within the last six months).

This is called RITA (Recent Infection Treatment Algorithm) or STARHS, or an avidity test.

The results are interpreted together with your recent risk of exposure and/or whether you had symptoms of early infection.

CD4 and viral load: two essential blood tests

Your CD4 count and viral load will tell you most about HIV and your general health.

These two blood tests tell you about how much HIV much have already affected your health.

The pattern from several results used to be more important than any single first result. However, most people now start treatment (called ART) rather than just monitoring results.
ART is now routinely recommended whatever your CD4 and viral load results.
So although the trend is more important than any single result getting information about the trend is now unusual.
In recent infection, the CD4 and viral load results reflect changes due to seroconversion.
In chronic infection (longer than 6-12 months) the results generlly show how much damage HIV has already done.

CD4 count

The CD4 count tells you how much or little damage HIV has caused to your immune system.

Results are given as the number of cells in a cubic millimetre of blood (cells/mm3).

Without HIV treatment (ART), the CD4 count is likely to fall over time.
In all countries ART is routinely recommended at any CD4 count.

Viral load

The viral load test tells you how much HIV is circulating in your body.

The result is given as the number of copies of HIV in a millilitre of blood (copies/mL).

Viral load is highest in the 2 to 4 weeks after infection. During this time, called seroconversion, viral load can be over 10 million copies/mL.
The general pattern is that over the next few months, without ART your immune system would control HIV and brings viral load down. This is usually to less than 50,000 and often much lower.
Then, without ART, viral load gradually increases, reaching between 50,000 – 100,000 copies/mL after the first few years.
ART is now routinely recommended for everyone though. This means many people will never see their viral load go this high.
ART reduces viral load to undetectable levels. This leads to better health and prevent HIV transmission.

Resistance tests

In the UK, everyone should also be given a drug resistance test.

This is because roughly 1 in 10 people (10%) will have a virus that is already resistant to one of more HIV drugs.

This information is important to know about so that you can use ART that will be active.

Some drug resistance becomes more difficult to detect as you get further from the time of infection. This is why UK guidelines recommend a routine drug resistance test when you are first diagnosed.

You may need to ask your clinic for this test and for the results.

Other tests

Your doctor should give you a full medical check-up.

This should include:

Your height, weight, waist circumference, blood pressure and full medical history.
Blood tests to check for other infections, including sexually transmitted infections and hepatitis A, B and C, and TB if you are at risk.
Other bloods tests with check your liver and kidney function, blood lipids (cholesterol etc).
The subtype of HIV that you have.
You should also have the chance to speak to a health advisor and/or counsellor over your psychological health and your reaction to the HIV diagnosis.

All these tests are to get a good overview of your current health and to get baseline results to see how your health changes over time.