2: Diagnosis of STIs Flashcards
Diagnosis is made by microscopic visualization of organism in vaginal discharge. Point-of-care tests typically have higher sensitivity and specificity.
Trichomoniasis
Diagnosis by NAATs or culture. NAATs testing not formally approved for rectum or pharynx testing.
Gonorrhea
Vaginal cx or antigen testing or mobile/motile trichomonads identified on saline wet mount; Vaginal pH >5.
Trichomoniasis
Culture is a sensitive and highly specific method of diagnosis, but is no longer routinely performed because of the availability of nucleic acid amplification tests (NAATs).
Trichomoniasis
Can use first-catch urine or vaginal swabbings. Use NAATs, cell culture, direct immunofluorescence, enzyme immunoassay (EIA), and nucleic acid hybridization tests.
Chlamydia
Dark-field examination (bacteria present on sore) and direct fluorescent antibody.
Syphilis (early)
Serologic test for antibodies. Confirm with serologic test for RNA presence.
Hep C
H. ducreyi bacteria on culture definitive.
Chancroid
Diagnosis by NAATs preferred.
Chlamydia
Diagnosis is by physical exam and biopsy can be performed on cervical lesions if diagnosis is uncertain (esp if cancer suspected).
HPV
Painful ulcer w unilateral bubo. Darkfield microscopy eliminates syphilis. Serologic tests for syphilis and HIV.
Chancroid
Diagnosis based on findings of pelvic organ tenderness and signs of lower genital tract infection, including mucopurulent cervicitis and cervical friability. No single lab test is available.
PID
Isolation in cell culture or by polymerase chain reaction (PCR) is the preferred test.
Herpes
Serology results during latency and late infection stages.
Syphilis (this is confirmatory)
Initial screening is conducted with standard enzyme-linked immunosorbent assay (ELISA) or enzyme immunoassay (EIA) tests. Rapid tests are also available and yield results in minutes.
HIV
Confirmatory test is Western blot (WB) or indirect immunofluorescense assay (IFA).
HIV
Viral culture is less sensitive than PCS, but may work during vesicular stage of infection.
Herpes
Staining shows the cellular bodies.
Molluscum
Genital ulcers that are negative for syphilis and HSV.
Chancroid
Serologic type-specific glycoprotein G (IgG)–based assays. Not recommended in the general public. Used for false negatives and for asymptomatic partners of infected women.
Herpes
Serologic markers such as surface antigens and antibodies, as well as immunoglobulins.
Hep B
Discharge on exam. Negative gonorrhea test. WBC on gm stain of discharge. >2 WBCs per oil immersion on intraurethral smear. Positive leukocyte esterase test on first void urine. Microscopic exam of sediment from spun first void urine.
Nongonococcal Urethritis (NGU)
DNA testing with pap smear.
HPV (21+ age only)
Cerebrospinal fluid and reactive serologic tests (CS-VDRL and CSF FTA-ABS).
Neurosyphilis
Organism can only be identified by culture on a special medium that is mostly out of use. Low sensitivity even using this method.
Chancroid
Rule out diagnosis mainly. +Cervical motion tenderness/chandelier sign.
PID
Presumptive diagnosis with nontreponemal (VDRL and RDR) and treponemal serologic (FTA-ABS and TP-PA) tests.
Syphilis
Endometrial biopsy with histopathologic evidence of endometritis. Transvaginal sonography or magnetic resonance imaging techniques showing thickened, fluid-filled tubes with or without free pelvic fluid or tubo-ovarian complex, or Doppler studies suggesting pelvic infection (e.g., tubal hyperemia). Laparoscopic abnormalities.
PID (most specific criteria for diagnosis)
Diagnosis is by physical exam and history. Nits are usually visible to the naked eye. Crusts or scabs may be seen in pubic area.
Pediculosis (Lice)
