Yes. A viral load test measures the amount of HIV in a person’s blood. An undetectable viral load means that the amount of virus in a person’s blood is too low for the test to measure. It does not mean that there is no HIV in the person’s body. A person who has a low or undetectable viral load can pass HIV to someone else, although the risk is probably lower than if he or she had a high viral load. Risk reduction measures, like using condoms and not sharing needles, still need to be taken.
