5th Lecture: DIAGNOSING (A SELECT GROUP OF) STIs W/THE HELP OF YOUR FRIENDLY LABORATORY Flashcards
what are the learning objectives?
- identify: the correct test to choose from the diagnostic microbiology lab to make a diagnosis of sexually transmitted infections (STIs)
- discuss: what clinical and laboratory data help you reach a correct diagnosis in a patient presenting with dysuria or genital discomfort
- understand: the importance of confidentiality in making ANY diagnosis in an adolescent patient
Epidemiology of STIs and young people
- 19 million new cases per year
- one-half occur in people ages 15-24
- most asymptomatic and undiagnosed - New research: 1 in 4 teens has an STI
- In 2006, one-third of new infections were among people ages 13-29 (may be as high as 50%)
Case: Erica
- Erica is a 16 yr old female who presents with dysuria (painful urination)
- What is your differential diagnosis?
Differential Diagnosis?
What are the characteristics of Trichomonas infection symptoms wise in females?
- Female: 50% are symptomatic
- Foul-smelling, frothy discharge
- Vaginal itching or redness
- Dyspareunia (pain with sexual intercourse)
- Urge to urinate and dysuria
- Post-coital bleeding
- Excessive or prolonged mense
What are the characteristics of Trichomonas infection symptoms wise in males?
- most are asymptomatic and often missed
- If symptoms occur can present as NGU
- Consider trich in males with recurrent urethritis post adequate treatment
what are the symptoms of bacterial vaginosis?
- odorous discharge
2. itching
what is the prevalence of bacterial vaginosis among STI clinic patients?
found in 24-47%
what is the sequelae of bacterial vaginosis?
- pregnancy complications
2. possible increase in pelvic inflammatory disease (PID)
what are the symptoms of Candidiasis symptoms in female?
- experience genital itching or burning
2. “cottage cheese-like” discharge
what are the symptoms of Candidiasis symptoms in male?
itchy penile rash
how do you diagnose Trichomonas?
culture
- sensitivity: 85-90%
- specificity: 100%
antigen detection
- sensitivity: 83%
- specificity: 97%
- available test: OSOM Rapid Test
DNA probe
- sensitivity: 60-70%
- specificity: 100%
Wet Mount
How do you diagnose Candida?
Largely clinical diagnosis –> women can take themselves to any pharmacy and treat themselves for this
In order to diagnose bacterial vaginitis the presence of at least three of the following four criteria is required (Amsel’s criteria)?
- Whiff test positive for fishy or musty odor when alkaline KOH solution added to smear
- Clue cells (bacterial attached to the borders of epithelial cells, more than 20% of epithelial cells) –> gram stain is gold standard
- vaginal pH > 4.5
- a homogenous non-inflammatory discharge
chlamydia symptoms in female?
- female up to 75% asymptomatic
- heavy or prolonged menses (remember! abnormal periods can be STI)
- spotting
- dysmenorrhea (painful menses)
- dyspareunia
- vaginal discharge
symptoms of chlamydia in males?
- up to 50% asymptomatic
2. itchy penile rash
symptoms of gonorrhea in females?
- females, 50% are asymptomatic
- yellow or bloody vaginal discharge
- painful urination
- dysmenorrhea
symptoms of gonorrhea in males?
- 50% asymptomatic
- discharge from the penis with pain
- burning during urination
- swollen testicles
what diagnostic test do you order for cervicitis?
- nucleic acid amplification test (NAAT)
- markedly amplifies target nucleic acids
- self-collected vaginal swabs offer another sensitive specimen
- can also use first 10-15 cc of urine specimens from men and women - culture (only for medical legal purposes
what are the characteristics of Nucleic Acid Amplified Tests
- markedly amplifies target nucleic acids
- self-collected vaginal swabs are great
- provider can obtain specimen if already performing an exam
- Can also use first 10–15 cc of urine specimens from men and women (Must be > 2 hours after last void)
In case of Erica, what should also be consider further?
- HIV testing and Syphilis testing
- Make sure vaccinated for Hep B and HPV
- counsel/motivational interviewing
1 in 4
teen has STI
confidentiality
ensures better care
Questions for History of Present Illness
- onset and duration of symptoms
- description of symptoms
- associated symptoms (nausea/vomiting, fever/chills, back pain, abdominal pain, sores/lumps/bumps
5 Ps for sexual Hx
- Partners
- Prevention of pregnancy
- protections forom STIs
- Practices (types of sexes: anal, vaginal, oral)
- Past Hx of STIs
