STD Testing Procedures
by Erik Steel
A variety of procedures are used to detect the presence of sexually transmitted diseases. Some STDs can reliably be diagnosed based on visual cues, while others require blood or other fluid testing.
HIV tests are performed on blood, oral fluid or urine samples. Most HIV tests check for the presence of antibodies to the virus, although RNA tests can directly detect the virus and can give results somewhat earlier in infection.
Swabbed samples of cervical secretions, or urine or discharge from the penis can be used to test for chlamydia. People who test positive for chlamydia will sometimes also be advised to be tested for gonorrhea.
A sample is taken from the place on the body where infection is suspected; in addition to reproductive organs and the rectum, gonorrhea can infect the throat. Men's urine can be quickly and Gram stained for the presence of the bacterium, while other samples must be examined for bacterial DNA in the lab.
Genital herpes can be diagnosed during an outbreak by symptoms found visually during an examination, although a stain or culture can be taken to confirm diagnosis. When there are no symptoms present, a blood test can be run to detect antibodies or a sample can be taken from blood, tissue or spinal fluid to detect the virus directly.
Syphilis can be detected with a dark-field microscope using a swab from a syphilitic chancre. A blood test can also be used to detect antibodies.
A pap smear can detect evidence of human papillomavirus (HPV) infection but not HPV itself. A swab taken during a pap smear can be used to screen for the presence of HPV DNA.