Sexually transmitted disease laboratory tests

Diagnosis
STI tests may test for a single infection, or consist of a number of individual tests for any of a wide range of STIs, including tests for syphilis, trichomonas, gonorrhea, chlamydia, herpes, hepatitis and HIV tests. No procedure tests for all infectious agents. STI tests may be used for a number of reasons: Not all STIs are symptomatic, and symptoms may not appear immediately after infection. In some instances a disease can be carried with no symptoms, which leaves a greater risk of passing the disease on to others. There is often a window period after initial infection during which an STI test will be negative. During this period the infection may be transmissible. The duration of this period varies depending on the infection and the test.
 * as a diagnostic test to determine the cause of symptoms or illness
 * as a screening test to detect asymptomatic or presymptomatic infections
 * as a check that prospective sexual partners are free of disease before they engage in sex without safer sex precautions (for example, in fluid bonding, or for procreation).
 * as a check prior to or during pregnancy, to prevent harm to the baby
 * as a check after birth, to check that the baby has not caught an STI from the mother
 * to prevent the use of infected donated blood or organs
 * as part of the process of contact tracing from a known infected individual
 * as part of mass epidemiological surveillance