How effective is STI screening for HIV infection?

HIV tests look for virus, viral components, or the immune response to infection. These markers do not all appear at the same time. A test taken soon after exposure may be negative even when infection is developing, so the clinician may recommend testing again after the relevant window for the test used.

A reactive screening result is not the final diagnosis. The laboratory performs follow-up testing to confirm or clarify it. A non-reactive result is reassuring when testing is done at the appropriate time, but it should be interpreted alongside the exposure date, prevention medicines, and any symptoms.

Arrange confidential testing and tell the clinician exactly when and how the exposure occurred. If the exposure was recent, ask immediately whether post-exposure medication could be suitable; it is time-sensitive and should not wait for routine screening. Do not donate blood or share injecting equipment while awaiting advice.

Use condoms or pause sexual contact until you understand the result and follow-up plan. If a result is reactive, attend confirmatory testing and treatment counselling promptly. Modern care can control HIV and protect health, so a reactive screen is a reason for follow-up rather than a conclusion by itself.

Seek urgent medical advice after a recent high-risk exposure, especially if you develop fever, rash, sore throat, swollen glands, or a flu-like illness. These symptoms can have many causes, but early assessment may affect prevention and testing choices. Pregnancy or breastfeeding after a possible exposure also needs prompt advice.

Ask which HIV test is being used, when it can detect infection, whether repeat testing is needed, and whether post-exposure medication or testing for other STIs is appropriate.