HIV: testing, PrEP and PEP

If you may have been exposed to HIV, contact a sexual health clinic or A&E now in the UK, or an emergency department or urgent care provider in the US and elsewhere. Ask about PEP. It must start within 72 hours, and the sooner the better.

PEP stands for post-exposure prophylaxis. It’s medicine you take after a possible exposure to HIV. Don’t wait for symptoms or a home test result before you get checked. If more than 72 hours have passed, still contact a sexual health clinic or doctor for advice on testing.

Testing does not depend on how you feel

HIV is a virus that attacks the immune system. Symptoms alone can’t tell you whether you have HIV. A test is the only way to know. There’s no cure at the moment, but with treatment most people with HIV live a long, healthy life.

Tests usually use blood or fluid from your mouth. No HIV test can find an infection straight after exposure. There’s a gap before it shows up, called the window period. The clinic will take this into account when they tell you when to test and whether you need follow-up. If a home antibody test suggests you may have HIV, you need another test through a health service to confirm it.

HIV isn’t spread by everyday contact such as hugging, kissing, sharing food or shaking hands. You don’t need HIV prevention medicine for these.

What undetectable equals untransmittable means

HIV treatment can lower the amount of virus in the blood until tests can’t detect it. People on treatment who keep it at that level don’t pass HIV on through sex. This is called undetectable equals untransmittable, or U=U.

The HIV team checks the amount of virus (viral load) with blood tests. U=U is about passing HIV on through sex. It isn’t a reason to share needles or other injecting equipment. CDC says an undetectable viral load probably lowers the risk from shared equipment, but no one knows by how much.

PrEP is prevention before exposure

PrEP stands for pre-exposure prophylaxis. It’s medicine for people without HIV who may be exposed through sex or injecting drugs. Options include pills and injections. PrEP lowers the risk of HIV, but it doesn’t prevent pregnancy or other STIs.

You need an HIV test before PrEP is prescribed, and regular visits and tests while you take it. Follow your clinician’s instructions on how to use it and when you can rely on it to protect you. Don’t stop prescribed PrEP without talking to your doctor.

Tell the clinician if you’re trying to get pregnant, are pregnant or are breastfeeding. CDC says PrEP can help prevent HIV at these times, and recommends asking your healthcare provider whether it suits you.

Access and advice differ between countries

In the UK, PrEP is free from NHS sexual health clinics. In the US, CDC says most insurance plans and state Medicaid programmes cover PrEP. Ask the service to check the cost of the medicine, appointments and lab tests separately. Help-to-pay programmes may cover different parts of care.

WHO recommends several ways to prevent HIV. These are PrEP pills, a dapivirine vaginal ring, and long-acting injections of cabotegravir or lenacapavir. Ask a local clinician which options they can offer and which suit you.

Advice on on-demand PrEP differs too. NHS information describes it as an option for some people, but CDC doesn’t recommend it. Ask your prescribing clinic for a plan that suits you. Don’t use someone else’s schedule.

Getting help after an exposure

If you may have been exposed within the last 72 hours, you need a check for PEP straight away through the services above. For an exposure longer ago, arrange a test with a sexual health clinic or doctor. If you may be exposed again and again, ask about PrEP and a longer-term plan to prevent HIV.

Before you leave, ask who to contact with questions about your medicine and when to come back. Write down the plan in the clinician’s words, including any follow-up appointments, so you can look back at it later.