What It Is
HIV and STD screening tests are a group of laboratory tests used to detect infections that can be transmitted through sexual contact, including HIV along with various bacterial, viral, and parasitic infections grouped under the broader category of sexually transmitted diseases.
What They Check
Depending on the specific infection being tested for, these tests may detect antibodies the body produces in response to an infection, antigens produced by the infecting organism itself, or the genetic material of the organism directly. Different infections are often tested for using different specific methods best suited to detecting that particular organism.
Why They're Used
HIV and STD screening tests are commonly used as part of routine sexual health checkups, when specific symptoms suggest a possible infection, or as a precaution following potential exposure. Regular screening is also commonly recommended for people in certain circumstances where ongoing risk of exposure may be present.
How They're Done
Most of these tests require a blood sample, though some, depending on the specific infection, may instead use a urine sample or a swab taken from a relevant area. Results for some rapid tests can be available within minutes, while others require laboratory processing that takes longer.
Background
Testing methods for sexually transmitted infections have developed considerably over the past century, with major advances following the identification of HIV in the early 1980s, which led to significant investment in developing accurate, reliable testing methods for it specifically. Testing technology across this category has continued to advance, including the development of increasingly rapid tests, and screening remains an important tool for identifying and managing these infections at an early stage.