Types of HIV Testing
There are three main types of HIV tests: antibody tests, RNA (viral load) tests, and a combination test that detects both antibodies and viral protein called p24 (antibody-antigen test, or HIV Ab-Ag test). All tests are designed to detect HIV-1, which is the type of HIV in the United States. Some antibody tests and the combination test can also detect HIV-2 infections, which are usually limited to West Africa. No test is perfect; tests may be falsely positive or falsely negative or impossible to interpret (indeterminate, see below).
Positive test results are reportable to the health department in all 50 states and include the patient's name. This information is then reported to the CDC (without names) so that the epidemiology and infection spread rates can be monitored. The names sent to the state remain confidential and will not be reported to employers, family members, or other such people. Some states allow anonymous testing in which the patient's name is not recorded.