If you have had unprotected sex with a partner, you are at risk of picking up an STI ( sexually transmitted infection). It is commonplace for people to start worrying about this as soon as the sex is over and I often have patients asking me when they can accurately test for

STI’s. The problem is that most infections will take a while before we can detect them accurately by testing. This is called a window period. I thought it would be helpful for me to put up the window periods for different STI’s

We can test for HIV from as early as 10 days post contact now. This early detection test is very accurate and results take around 3-5 working days. There is also a test we can do 28 days post contact with results the same day. Finally there is the onsite HIV test, which can be done from 90 days post contact and gives an instant result.

Hepatitis B/C:
Early detection test from 10 days post-contact. Normal antibody testing can be done from 1-month post-contact but needs repeating at around 3 months.

From 1-month post-contact, repeat testing at 3 months advised

Herpes blood test:
From one-month post-contact, repeat testing at 3- 6 months post contact advised

From 7 days post-contact, don’t urinate for at least 2 hours before testing

Chlamydia :
From 10 days post-contact, don’t urinate for at least 2 hours before testing

However, as always if you have symptoms, it is better to get them checked out as soon as possible. Also if you think you have potentially been exposed to HIV, please see a Doctor as soon as possible as there are treatments we can provide to reduce the chances of infection. This is called PEP ( post-exposure prophylaxis) and needs to be started within 72 hours of the contact.