STI Flashcards
which STI legally required to be reported upon diagnosis
gonorrhoea, non-gonococcal urethritis, syphilis, chlamydia, genital herpes, HIV/AIDS, viral hepatitis
gonorrhoea general
1) causative organism
- neisseria gonorrhoea (intracellular gram neg diplococci)
2) mode of transmission
- sex, mother-to-child during childbirth
diagnosis of gonorrhea
1) gram stain of genital discharge
2) culture
3) NAAT
infectious site for gonorrhoea
urethritis, cervicitis, proctitis, pharyngitis, conjunctivitis, disseminated
clinical presentation of gonorrhoea
- can be asymptomatic
- symptoms
1) male: purulent urethral discharge
2) female: mucopurulent vaginal discharge
3) both: dysuria, urinary frequency - complications
1) male: epididymitis, prostatitis, urethral stricture
2) female: pelvic inflammatory disease, ectopic pregnancy, infertility
3) both: disseminated disease, skin lesion, tenosynovitis, monoarticular arthritis
management of uncomplicated gonorrhoea
- X fluoroquinolone (resistance)
- gonococcal infection treatment + anti-chlamydia therapy (doxycycline) for concurrent treatment unless X chlamydia
- 1st line: ceftriaxone
- alternative: gentamycin + azithromycin
chlamydia general
- causative agent: chlamydia trachomitis
- infect various site (similar to gonorrhoea)
- transmission: sex, mother-to-child
diagnosis of chlamydia
NAAT
clinical presentation of chlamydia
milder symptoms than gonorrhoea, similar complications to gonorrhoea
treatment for chlamydia
- 1st line: doxycycline
- alternative: azithromycin (use 1st cuz adherence), levofloxacin
management of sex partners for gonorrhea & chlamydia
- evaluate & treat sexual partner in last 60 days
- if last sexual exposure > 60 days then treat most recent partner
- if receiving treatment then abstain from sex 7 days after treatment (prevent transmission)
- abstain from sexual intercourse until all sexual partners treated (prevent reinfection)
syphilis general
- causative organism: treponema pallidum
- transmission: sex, mother-to-child (transplacental)
serological tests for syphilis
1) treponemal
- use treponemal antigen to detect treponemal activity
- confirmatory test cuz more sensitive & specific
- reactive for life X for monitoring response but if infected before
2) non-treponemal
- cardiolipin to detect treponemal antibodies
- types: VDRL slide test/RPR card test
- +ve test: any stage of syphilis
- quantitative test (measure response)
treat primary/secondary/early latent syphilis
1) IM benzathine pen G 2.4 million units
2) pen allergy: PO doxycycline 100mg BD 14 days
- take w food
- take w water + upright position at least 30 mins
- X milk, divalent cation (2 hrs)
- SE: GI, photosensitivity
treat late latent (> 1 yr)/unknown duration/tertiary syphilis
1) IM benzathine pen G 2.4 million units once a wk for 3 doses
2) pen allergy: PO doxycycline 100mg BD 28 days
treat neurosyphilis
1) IV crystalline pen G (3-4 million units q4h | 18-24 MU/d as continuous infusion 10-14 days) or IV procaine pen G (2.4 MU daily) + PO probenecid (500mg qid) 10-14 days
2) pen allergy: IV/IM ceftriaxone 2g daily 10-14 days
- concern cross-sensitivity: skin test to confirm pen allergy, desensitise if required
what is the function of PO probenecid in neurosyphilis treatment?
reduce secretion of penicillin = increase penicillin concentration in systemic
monitoring for syphilis treatmtent response - JH reaction
- acute febrile reaction + headache, myalgia
- within first 24 hrs
- not preventable, can give antipyretics to help
monitoring for syphilis treatment response - pri/secondary/latent
- quantitative VDRL or RPR 3, 6, 12, 18, 24 months
- treatment success if decrease of VDRL/RPR titre by at least fourfold
** lower antibody = lesser antibody titre (good) = body X producing antibody to fight antigen = little antigen
monitoring for syphilis treatment response - neurosyphilis
CSF examination every 6 month until CSF normal
syphilis management of sex partners
- all at risk sexual partners evaluated & tested
- X sex w new partners until all lesions healed
genital herpes causative agents
herpes simplex virus (HSV-1, HSV2)
- HSV-2 cause recurrence
cycle of HSV infection
1) primary mucocutaneous infection
2) infection of nerve ganglia
3) establishment of latency
4) reactivation
5) recurrent outbreak/flares
route of transmission for HSV infection
1) body fluids
2) intimate skin-to-skin contact
infection progress for HSV
1) Vesicles develop over 7 - 10 days
2) heal in 2-4 wks
3) intermittent viral shedding from epithelial cells
clinical presentation of genital herpes
1) multiple painful vesicles (break to form ulcerative lesions)
2) local itching, pain, tender inguinal lymphadenopathy
3) flu-like symptoms
- fever, headache, malaise
first few days after appearance of lesions
4) prodromal symptoms
- mild burning, itching, tingling
- prior to appearance of recurrent lesion
type-specific (HSV 1/2) serologic test
- Ab to HSV develop during first few wks after infection, persist indefinitely
- X useful for first ep of infection cuz take 6-8 wks for serological detection
- HSV-2 Ab = anogenital infection
genital herpes supportive care
1) warm saline bath relieve discomfort
2) symptom management: analgesia, anti-itch
3) good genital hygiene to prevent superinfection
4) counselling
MOA of antivirals for genital herpes
inhibit viral DNA polymerase -> inhibit DNA synthesis & replication
types of antivirals for genital herpes
1) acyclovir
- PO 400mg TDS 7-10 days
- severe/complicaations that require hospitalisation: IV 10mg/kg q8h x 2-7 days + PO 10 days
- hydration to prevent crystallisation in renal tubule
2) valacyclovir
- PO 1g BD for 7-10 days
pharmacological management of recurrent genital herpes
antiviral as chronic/suppressive therapy
advantages of chronic suppressive therapy for genital herpes
- reduce frequency by 70-80%
- X symptomatic outbreak = improve QoL
- long term safety & efficacy
- decrease risk of transmission + consistent condom use & abstinence
disadvantages of chronic suppressive for recurrent genital herpes
$$$$$$, compliance
chronic suppressive therapy regimen for genital herpes
- acyclovir 400mg PO BD
- valacyclovir 500mg PO OD
- valacyclovir 1g PO OD
- when indefinite suppression indicated:
** complicated disease course (disseminated disease: encephalitis, meningitis, keratitis)
** immunocompromised host
advantages of episodic treatment for genital herpes
1) Shorten duration & severity of symptoms
2) cheaper
3) more likely to be compliant
disadvantages of episodic treatment for genital herpes
1) require indication of therapy within 1 day of lesion onset or during prodromal that precedes some outbreaks
2) X reduce risk of transmission
possible meds for episodic treatment for recurrent genital herpes
- acyclovir 800mg oral BD 5 days
- acyclovir 800mg TID for 2 days
- valacyclovir 500mg oral BD 3 days
- valacyclovir 1g oral OD 5 days
