How Are Sexually Transmitted Infections Diagnosed?
Diagnoses of some STIs are difficult. Chlamydia is asymptomatic and the mild symptomatology of syphilis in its early stages insidiously progress to cognitive impairment. Hepatitis may not be apparent without testing until there is impairment of hepatobiliary function. The rest of the STIs in general present with painful or disturbing signs and symptoms that prompt patients to seek care:
Herpes is exquisitely painful. The notoriety of HIV has raised a public sensibility toward testing after any unprotected sexual encounter. Trichomonas and bacterial vaginosis, in women, cause vaginal discharge, odor, and discomfort. Genital warts and molluscum contagiosum cause skin lesions that are innocuous but cosmetically disturbing and psychologically upsetting.
50% of those with an STI have an additional STI or more. For this reason, those at risk are screened for the elusive Chlamydia, syphilis, HPV, and hepatitis diagnoses whenever a patient is tested for any of the others.
The “exposure” panel for STIs include the following:
- HPV: Pap smear and HPV DNA testing in women for human papilloma virus. HPV in the cervix of women is tested as to its HPV “type,” as some cause cervical cancer while others only genital warts (condylomata).
- Trichomonas and bacterial vaginosis: A microscopic evaluation of vaginal and/or penile discharge.
- Chlamydia and gonorrhea: Cultures from the urethra and anus in men and the urethra, cervix, vagina, vaginal glands, and anus of women.
- Syphilis: A blood test that serves as a screen, and if positive, definitive antibody blood testing.
- Herpes simplex I and II: Cultures directly from the lesion.
- Hepatitis B and C: Blood work for the hepatitis antigens.
- Molluscum contagiosum: Simple inspection of the classic structures of this infection.
When patients present with later stages of an STI, advanced diagnostics are used. For example, gonorrhea spreading to the joints can be determined by joint fluid aspiration of a swollen, inflamed joint. Intra-abdominal cultures are possible during surgery for ovarian abscesses or infertility due to chlamydia or gonorrhea.