HIV may still be found in genital fluids (semen, vaginal fluids). The viral load test only measures the amount of HIV in the blood. Although ART also lowers viral load in genital fluids, HIV can sometimes be present in genital fluids even when it is undetectable in the blood. But the amount of virus present may not be enough to establish infection
Your viral load may go up between tests. When this happens, you might be more likely to transmit HIV to your partner(s). Your viral load may go up without you knowing it because you may not feel any different. Some people have “blips” in their viral load results that often disappear when the next viral load test is done. A blip is usually a small increase that changes a person’s viral load test results from undetectable to detectable. Often the blip is small enough that the person is still considered to have a suppressed viral load and is unlikely to transmit HIV and or experience any signs of disease progression.
Sexually transmitted diseases (STDs) increase viral load in genital fluids. This means that if you are living with HIV and also have an STD, you may be able to transmit HIV to your partner(s) even if the blood viral load is undetectable.