Diagnosing STIs with Laboratory Help Flashcards
What assurance enables better care for adolescents in the clinic being treated for an STI?
Confidentiality assurance!
When a patient presents with dysuria, what is your initial leading differential?
UTI
What is your DDx for dysuria?
- UTI
- Genital Tract Infection - Cervicitis, Vaginitis
- Skin Related Abnormalities/Mucosall Perineal - Herpes, Trauma
What are the 5 P’s of a sexual Hx?
- Partners - Gender, Number
- Prevention of Pregnancy
- Protection from STIs
- Practices - type of sex
- Past Hx of STIs
What are the three big bugs that cause vaginitis?
- Trichomonas
- Bacterial Vaginitis
- Candida Vaginitis
What is the typical presentation of a person with trichomoniasis?
Generally females present with Syx with foul-smelling, frothy discharge, vaginal itching/redness, urge to urinate and dysuria
What is bacterial vaginosis?
Fewer than normal hydrogen peroxide producing lactobacilli and prevalence of other types of bacteria in the vagina
Typical presentation and sequelae of BV?
Odorous discharge and itching; Pregnancy complications/PID
What is the Dx? Typical description and presentation?
Candidiasis; Genital itching/ burning, cottage cheese-like discharge
A female patient has trichomonas. What are two findings that strongly suggest this Dx?
- Frothy gray/yellow-green malodorous discharge
- Cervical petechiae - Strawberry cervix
What vaginal infection(s) occur(s) at a vaginal pH of >4.5?
Bacterial vaginosis and Trichomoniasis
What tests are available for Trichomonas Dx?
- Culture
- Rapid Antigen Test
- DNA Probe
- Wet Mount
What tests are available for Candida Dx? What is typically used?
- DNA Probe
- Wet Mount
Largely a clinical Dx
What are Amsel’s Criteria?
3/4 need to be positive to Dx BV:
- Whiff Test - Fishy/Musty odor when KOH added to smear
- Clue Cells - bacteria attached to >20% of borders of epithelial cells
- ** Vaginal pH** > 4.5
- Homogenous non-inflamm discharge
pH paper shows pH > 4.5, a rapid Trich test is unavailable, we don’t have time to use a KOH test, and you’re too dumb to use a microscope. How are we going to determine whether the infection is BV or Trich?
Treat presumptively! (Tx for BV and Trich is Metronidazole)
When treating a patient for Trich, what is another important consideration?
Must Tx partner!
What is the most important cause of cervicitis?
Chlamydia
Important signs of chlamydia infection?
- Heavy/prolonged menses
- Spotting
- Dysmenorrhea
- Dyspareunia
- Vagina Discharge
What are the Syx of females and males with Gonorrhea?
Females:
- Yellow/bloody vaginal discharge
- Dysuria
- Dysmenorrhea
Males
- Painful penile discharge
- Burning with urination
- Orchitis
What is the gold standard to evaluate for cervicitis?
Nucleic Acid Amplification Test (NAAT)
When would you culture a suspected Gonorrhea/Chlamydia infection?
For medicolegal purposes
Describe the specimen collection method for NAAT
Both: 10-15 cc of urine > 2 hr after last void
Women: Vaginal swabs
Typical pH with a candida infection?
pH < 4.5
A KOH whiff test is positive. What is the Dx?
The Dx is either BV or Trich. BV is classically foul/fishy smell but Trich is often positive as well. Furrther testing is needed (Examine cervix, wet mount)
What are the typical findings on PE for candidiasis?
- Inflammation and erythema
- Cottage-cheese discharge
