How long does it take for an STI (for example HIV/AIDS) to be picked up by a test?
If you are exposed to the Human Immunodeficiency Virus (or HIV), the virus that causes AIDS, it takes some time (a few days to months) for your body to develop antibodies against the virus that can be detected by the blood test. This is the reason why it is recommended to have a second blood test 3 to 6 months later to detect any new antibodies. In the meantime, use condoms to protect you and your sexual partner. STI’s that are picked up by culture (such as chlamydia or gonorrhea) are generally detectable right away, especially if there are symptoms. If you have any ulcers on your genitals, these should be swabbed for herpes and syphilis while they are still visible. If a syphilis infection is new the blood test may not yet be positive. Talk to your doctor. If there is any doubt, these tests can be repeated in a few months.
