IC18: STIs Flashcards
What are the risk factors for STIs? (5)
1) Unprotected sexual intercourse (no barrier method)
2) Number of sexual partners (have multiple sex partners or contact with someone with multiple sex partners)
3) MSM (Gay sex)
4) Prostitution (Commercial Sex worker, CSW)
5) Illicit drug use
Risk of being exposed to blood from contaminated needles
Higher chance of risky behaviour due to drug use
What are non-pharmacological advice for STI prevention?
1) Abstinence and reduction of number of sexual partners
Long term, mutually monogamous relationship with an uninfected partner
2) Barrier contraceptive methods
Male latex condoms when used consistently and correctly
3) Avoid drug abuse and sharing needles
4) Pre-exposure vaccination
HPV (Human papilloma virus), Hepatitis B
5) Pre- and Post- exposure prophylaxis
What are the symptoms of uncomplicated urogenital gonorrhea?
1) Dysuria
2) Urinary frequency
3) Purulent Urethral discharge (in males)/ Mucopurulent vaginal discharge (in females)
What diagnostic tests can be done for patient with gonorrhea?
1) Gram stain of genital discharge
2) Culture (done if suspect will have resistance to get AST)
3) NAAT (Nucleic Acid Amplification Test; PCR)
What is the treatment regimen for uncomplicated gonorrhea if patient is 100kg and the drug of choice is available?
Ceftriaxone 500mg IM single dose + PO Doxycycline 100mg BD x 7 days (if Chlamydia not excluded)
What is the treatment regimen for uncomplicated gonorrhea if patient is 151 kg and the drug of choice is available?
Ceftriaxone 1000mg IM single dose + PO Doxycycline 100mg BD x 7 days (if Chlamydia not excluded)
What is the treatment regimen for uncomplicated gonorrhea if the drug of choice is not available?
Gentamicin 240mg IM single dose + PO Azithromycin 2g single dose
- No need Doxycycline as Azithromycin can cover both Gonorrhea and Chlamydia
- AG to prevent Macrolide resistance
OR
PO Cefixime 800mg single dose (not available in SG)
How would you manage the sex partners of someone who has been diagnosed with Gonorrhea?
o Sex partners in the last 60 days should be evaluated and treated. If last sexual exposure > 60 days, the most recent partner to be treated.
o Abstain from sexual activity for 7 days after treatment (i.e. 7 days after receiving treatment and resolution of symptoms, if present).
o To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all their sex partners have been treated.
How would you manage the sex partners of someone who has been diagnosed with Chlamydia?
o Sex partners in the last 60 days should be evaluated and treated. If last sexual exposure > 60 days, the most recent partner to be treated.
o Abstain from sexual intercourse for 7 days after single dose therapy, or until completion of a 7-day regimen and resolution of symptoms if present.
o To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all their sex partners have been treated.
Is test of cure for Gonorrhea recommended in SG?
Yes
State when test for cure of Chlamydia necessary
Test of cure is not required unless specific concerns (e.g. pregnancy, non-adherence) or symptoms persist
State the recommended regimen for Chlamydia if patient is adherent
PO Doxycycline 100mg BD for 7 days
State the recommended regimen for Chlamydia if patient is non-adherent
PO Azithromycin 1g single dose
Which FQ may be used in Chlamydia as alternative regimen and state the regimen
PO Levofloxacin 500mg once daily for 7 days
What are the tests used to confirm a diagnosis of syphilis
Darkfield microscopy of exudates from lesions
* Look for spirochete (wriggly) bacteria
Requires 2 serological tests (mainstay): treponemal and non-treponemal tests
Compare and contrast the Treponemal and Non-treponemal tests.
1) Treponemal test use treponemal antigen while non-treponemal use non-treponemal antigen (e.g cardiolipin) to detect presence of trepnemal antibody
2) Treponemal test more sensitive and specific than non-treponemal test
3) Treponemal used as confirmation test but not for monitoring of response. Non-treponemal used to monitor response to treatment
4) Nontreponemal test titres usually declines after treatment and can become non-reactive with time. Treponemal test may remain reactive for life, hence not for monitoring response to treatment
What are examples of Treponemal tests?
a) T. pallidum Haemaggluntination test (TPHA)
b) T. pallidum passive particle agglutination assay (TPPA)
c) Venereal Disease Research Laboratory (VDRL) slide test
d) Rapid plasma reagin (RPR) card test
TPHA and TPPA
What are examples of non-Treponemal tests?
a) T. pallidum Haemaggluntination test (TPHA)
b) T. pallidum passive particle agglutination assay (TPPA)
c) Venereal Disease Research Laboratory (VDRL) slide test
d) Rapid plasma reagin (RPR) card test
VDRL, RPR
What is the result reported for VDRL/RPR test?
The most dilute serum concentration with a positive reaction (e.g. result 1:16 positive means at 1:32 no reaction seen) -> high antibody load = higher ratio (need more dilution till negative reaction)
What is the recommended regimen for a patient who was diagnosed with Syphilis in the doctors office today ? (Pt had syphilis symptoms 11 months ago but did not seek treatment; no penicillin allergy reported)
IM Benzathine penicillin G 2.4 million units x 1 dose
What is the recommended regimen for a patient who was diagnosed with Syphilis in the doctors office today ? (Pt had syphilis symptoms 11 months ago but did not seek treatment; penicillin allergy reported)
PO Doxycycline 100mg BD for 14 days
What is the recommended regimen(s) for someone with syphilis and presents today with difficulty walking due to gummatous lesions?
IM Benzathine penicillin G 2.4 million units once a week x 3 doses
OR
PO Doxycycline 100 mg bid x 28 days (penicillin allergy)
What are the possible regimens for a person with Neurosyphilis?
IV Crystalline penicillin G 3-4 million units q4h or 18-24 MU/d as continuous infusion x 10-14 days
OR
IM Procaine penicillin G 2.4 MU daily plus PO probenecid 500mg QDS x 10-14 days
OR
IV/IM Ceftriaxone 2g daily x 10-14 days (if penicillin allergy)
Define what is considered as treatment failure for syphilis and how to manage it
Defined as (at 6 months):
* Show sign and symptoms of disease or
* Failure to decrease VDRL or RPR titre by fourfold OR increase (e.g 1:16 to 1:64)
Management:
* Re-treat and re-evaluate for unrecognised neurosyphilis
State how you would monitor a patient with syphilis (no neurosyphillis)
Monitor for:
1) The Jarisch-Herxheimer reaction is an acute febrile reaction frequently accompanied by headache, myalgia, and other symptoms that usually occur within the first 24 hours after any therapy for syphilis.
2) Quantitative VDRL or RPR at 3, 6, 12, 18 and 24 months to measure response
o 6, 12 and 24 months are the key times
o Treatment success = decrease of VDRL or RPR titre by at least fourfold e.g. 1:64 to 1:16)
State how you would monitor a patient with neurosyphillis
Monitor for:
1) The Jarisch-Herxheimer reaction is an acute febrile reaction frequently accompanied by headache, myalgia, and other symptoms that usually occur within the first 24 hours after any therapy for syphilis.
2) Quantitative VDRL or RPR at 3, 6, 12, 18 and 24 months to measure response
o Treatment success = decrease of VDRL or RPR titre by at least fourfold e.g. 1:64 to 1:16)
3) Lumbar puncture (CSF examination) every 6 months until CSF normal
How would you manage sex partners of patient with Syphilis?
o All at risk sexual partners should be evaluated for STIs and treated if tested positive.
o Persons who receive syphilis treatment must abstain from sexual contact with new partners until the doctor says ok to resume.
What are the clinical symptoms of HSV?
o Classical painful multiple vesicular or ulcerative lesions (when vesicles burst)
o Also local itching, pain, tender inguinal lymphadenopathy
o Flu like symptoms (e.g., fever, headache, malaise) during first few days after appearance of lesions.
o Prodromal symptoms like mild burning, itching or tingling are seen in approximately 50% of patients prior to appearance of recurrent lesions (in recurrent disease).
o Symptoms less severe in recurrent disease (less lesions, heal faster, milder symptoms)
What are the diagnostic tests available for first episode of HSV?
- Viral cell culture (hard to do so not main diagnostic test)
- NAAT (PCR) for HSV DNA from genital lesions (main test)
What diagnostic tests are available for HSV (not first episode)
- Virologic Tests:
1) Viral cell culture (hard to do so not main diagnostic test)
2) NAAT (PCR) for HSV DNA from genital lesions (main test) - Type-specific serologic tests (HSV-1 or HSV-2)
What are the clinical effects of antiviral treatment of HSV?
o Reduce viral shedding
o Reduce duration of symptoms and
o Reduce time to healing of 1st episode
- Note: Does not prevent latency or affect frequency and severity of recurrent disease after drug is discontinued
State the possible antiviral regimens for first episode of herpes (assuming non-severe disease)
Acyclovir:
PO: 400mg TDS for 7-10 days
Valacyclovir:
PO 1g BD for 7-10 days (higher F so can give less freq compared to Acyclovir)
Duration of treatment can extend beyond 10 days if healing incomplete
State the possible antiviral regimen(s) for first episode of herpes (severe disease/ hospitalisation/ immunosuppressed)
IV Acyclovir: 5-10 mg/kg q8h x 2-7 days, followed by PO to complete a total 10 days therapy
What are the possible regimens for chronic suppressive therapy of HSV?
- PO Acyclovir 400mg BD
- PO Valacyclovir 500mg once daily*
o Might be less effective for patients with frequent recurrences (>10 per year) - PO Valacyclovir 1g once daily
o Preferred over 500mg regimen if > 10 recurrence per year
PO Famcyclovir 250mg BD also possible but not in SG