How Accurate is a Rapid STD Test?

Rapid STI test performance varies widely depending on the infection, test technology, specimen type, collection method, and timing. Sensitivity describes how often a test detects an infection that is present and is not the same as overall accuracy. Some rapid HIV tests and rapid molecular tests for chlamydia and gonorrhea perform very well, but results vary by the specific test, specimen, infection site, and timing. Patients should check the performance information for the test being used. Testing too soon after exposure can miss an infection. The reason depends on the test: HIV and some other tests look for antibodies or antigens, while tests for infections such as chlamydia and gonorrhea may not detect the organism early enough after exposure. Testing too soon after exposure can increase the chance of a false-negative result. The relative likelihood of false-negative and false-positive results depends on the specific test and the population being tested. Whether a positive result needs additional testing depends on the infection and the test used. For example, a reactive rapid HIV screening result must be followed by supplemental testing, while some other rapid molecular test results may not routinely require confirmation. The convenience of same-day results makes rapid testing valuable for initial screening, but healthcare providers often recommend follow-up testing for comprehensive STD screening.