IC18b PR3151 STI Flashcards
what are the bacteira STIs?
syphilis
gonorrhea
nongonococcal urethritis
chancroid
LGV (lyphogranuloma venereum)
Granuloma inguinale
what is the bacteria causing syphilis?
treponema pallidum
what is the bacteria causing gonorrhoea?
Neisseria gonorrheae (gram negative intracellular diplococci)
what is the bacteria causing nongonococcal urethritis?
CUM:
- chlamydia trachomatis
- ureaplasma
- mycoplasma genitalium
what is the bacteria causing chancroid
haemophilus ducreyi
what is the bacteria causing LGV
chlamydia trachomatis
what is the bacteria causing granuloma inguinale
calymmatobacteria granulomatis
what are the viral STIs?
anogenital herpes
anogenital warts
viral hepatitis
HIV/AIDS
molluscum contagiosum
what is the virus causing anogenital herpes
HSV type 1 -2 (herpes simplex)
what is the virus causing ano genital warts
HPV
what is the virus casuing hepatitis
hep A B C
what is the virus causing molluscum contagiosum
molluscum contagiosum virus
what are fungal STIs?
vaginal candidiasis
what is the fungi causing vaginal candidiasis
candida albicans
what are the parasite STIs?
scabies
pediculosis pubis
what is the parasite causing scabies
Sarcoptes scabiei
what is the parasite causing pediculosis pubis
Phthirus pubis
what are the two STIs that can also be transmitted via non-sexual contact?
vaginal candidiasis and
scabies
what STis need to be reported for MD131 under the infectious diseases act?
syphilis
gonorrhea
nongonococcal urethritis
chlamydia
genital herpes
viral hepatitis
HIV/AIDS
when should MD131 be reported?
within 72 hours
what is the purpose of MD131?
for monitoring and evaluation of national control programmes
what is collected in MD131?
demographic data (age, gender, ethnicity, nationality)
not for contact tracing or case detection
what special actions must be taken for HIV/AIDS?
partner notification is mandatory
what are the modes of transmission of STIs?
1) contaminated blood
2) sexual intercourse with a contaminated individual
3) contact of broken skin with eg open sores, genital discharge
4) mother to child
relate pathogen to transmissio
1) pregnancy
2) child birth
3) breast feeding
1) pregnancy: HIV, syphilis
2) child birth: chlamydia, HSV, gonorrhea
3) breast feeding; HIV
what are the risk factors for STIs
unprotected sex
multiple sex partners
illicit drug users
commercial sex workers
male-male sex
what are the individual prevention methods for STIs?
abstinence and reduction in number of sex partners
barrier contraceptives
avoid drug abuse and sharing needles
pre exposure vaccination: HPV, hepB
pre and post exposure prophylaxis:
gonorrhea transmission method
mother to child during childbirth
sexual intercourse
diagnostic test for gonorrhea
culture
gram stain
NAAT nucleic acid amplification test
infection sites for gonorrhea
Urethritis
Cervicitis
Proctitis (rectal)
Pharyngitis
Conjunctivitis
Disseminated
symptoms of uncomplicated urogenital gonorrhoea? (male and female)
male: purulent urethral discharge, dysuria, urinary frequency
female: mucopurulent vaginal discharge, dysuria, urinary frequency
complications of gonorrhea if untreated?
Males –epididymitis, prostatitis, urethral stricture, disseminated disease
Females –Pelvic inflammatory disease, ectopic pregnancy, infertility, disseminated disease
Both -Disseminated –skin lesions, tenosynovitis, monoarticular arthritis
treatment recommendations for uncomplicated gonorrhoea
avoid fluoroquinolones due to high rates of resistance
add on therapy (doxycycline); treatment of gonorrhoea should be accompanied by anti-chlamydial therapy (typically occur together)
what is the first line regimen for gonorrhea treatment?
for adults <150kg
- ceftriaxone IM 500mg single dose
for adults ≥150kg
- ceftriaxone IM 1g single dose
concurrent anti-chlamydia treatment (if not excluded)
- doxycycline PO 100mg BD x 7days
what is the alternative regimen for gonorrhea treatment?
1)
gentamicin 240mg IM single dose
AND
azithromycin 2g PO single dose
OR
2)
cefexime 800mg PO single dose
ADD on doxycycline PO 100mg BD x7 days if chlamydia not excluded
management of sex partners for gonorrhoea?
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.
To minimize disease transmission, persons treated for gonorrhoea should be instructed to abstain from sexual activity for 7 days after treatment (ie. 7 days after receiving treatment and resolution of symptoms, if symptom was present).
To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all their sex partners have been treated.
chlamydia description? pathogen, mode of transmission, symptoms
by chlamydia trachomatis
similar mode of transmission and presentation as gonorrhoea
first line treatment regimen for chlamydia?
PO doxycycline 100mg BD x 7 days
alternative treatment regimen for chlamydia?
PO azithromycin 1g single dose
OR
PO levofloxacin 500mg OD x7days
which drug no longer recommended for chlamydia?
erythromycin due to GI side effects affecting adherence
other FQs are also ineffective (minus levofloxacin)
management of sex partners for chlamydia?
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.
To minimize disease transmission, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy, or until completion of a 7-day regimen and resolution of symptoms if was present.
To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all their sex partners have been treated.
transmission methods for syphilis
mother to child (during pregnancy)
sexual contact
what is the diagnosis test used for syphilis
darkfield microscopy of exudates from lesions
how many tests (and type of tests) are needed for syphilis?
2 serological tests:
1 treponemal and 1 non-treponemal test
describe the treponemal tests used for syphilis
Uses treponemalantigen to detect treponemalantibody
EgT. pallidum Haemaggluntinationtest (TPHA), T. pallidum passive particle agglutination assay(TPPA)
Treponemal tests are more sensitive and specific than nontreponemal tests, used as confirmatory tests.
May remain reactive for life, hence not for monitoring response to treatment
describe the non-treponemal tests used for syphilis
Uses nontreponemalantigen (cardiolipin) to detect treponemalantibodies
2 different commonly used test
a) Venereal Disease Research Laboratory (VDRL) slide test
b) Rapid plasma reagin(RPR) card test
The result reported in the quantitativeVDRL/RPR test is the most dilute serum concentration with a positive reaction (eg result 1:16 positive means at 1:32 no reaction seen)
Antibody titres correlates with disease activity and hence used as a tool to monitor response to treatment(VDRL/RPR are not interchangeable; need to use the same test for monitoring)
Nontreponemal test titres usually declines after treatment and can become non-reactive with time
first-line treatment regimen for primary, secondary or early latent (<1yr) syphilis?
benzathine pen G IM 2.4 mu single dose
first line treatment regimen for late latent (>1yr) or unknown duration syphilis?
benzathine pen G IM 2.4 mu once a week x 3 doses
first line treatment regimen for neurosyphilis?
iv crystalline pen G 3-4 mu q4 x10-14 days
OR
iv crystalline pen G 18-24 mu continuous infusion x10-14 days
OR
im procaine pen G 2.4 mu OD + PO probenecid 500mg QD
x10-14 days
(pen allergy) alternative treatment regimen for primary, secondary or early latent (<1yr) syphilis?
PO doxycycline 100mg BD x10-14days
(pen allergy) alternative treatment regimen for late latent (>1yr) or unknown duration syphilis?
PO doxycycline 100mg BD x28days
(therapeutic response syphilis) what is an accompanying reaction after syphilis therapy?
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.
Antipyretics will help but not prevent.
(pen allergy) alternative treatment regimen for neurosyphilis?
IV/ IM ceftriaxone 2g daily x 10-14 days
If concern for cross-sensitivity –skin test to confirm penicillin allergy, desensitize if necessary
(therapeutic response syphilis) monitoring for Primary / secondary/ Latent syphilis?
what indicates tx success?
HOW frequent should monitoring be?
Quantitative VDRL or RPR at 3, 6, 12, 18 and 24months
treatment success = decrease of VDRL or RPR titre by at least fourfold (eg1:64 to 1:16)
(therapeutic response syphilis) monitoring for neurosyphilis?
CSF examination every 6 month until CSF normal
what indicates treatment failure for syphilis?
Treatment failure at 6 mths
- show sign and symptoms of disease or
- Failure to decrVDRL or RPR titre by fourfold OR incr(1:16 to 1:64)
Retreat and re-evaluate for unrecognised neurosyphilis
Managementof sexual partners for syphilis?
All at risk sexual partners should be evaluated for STIs and treated if tested positive.
Persons who receive syphilis treatment must abstain from sexual contact with new partners until the syphilis lesions are completely healed. Patient with syphilis need careful assessment of whether they have responded and if their symptoms resolved by the doctor, it is goodto advise patient to check with the doctor if they have been fully treated.
what are the characteristics of genital herpes?
caused be HSV type 1 and 2
mainly type 2
chronic and lifelong infection,
may be asymptomatic while shedding (of epithelial cells) and transmission occurs.
what is the cycle of infection for genital herpes?
five stages:
primary mucocutaneous infection,
infection of the nerve ganglia,
establishment of latency,
reactivation, and
recurrent outbreaks/flairs.
how long do genital herpes vesicles take to develop and heal?
7-10 days
2-4 weeks to heal
method of transmission for genital herpes?
body fluids
intimate skin contact
presentation/symptoms of genital herpes?
classical painful multiple vesicular or ulcerative lesions
Also local itching, pain, tender inguinal lymphadenopathy
Flu-like symptoms (e.g., fever, headache, malaise) during first few days after appearance of lesions.
Prodromal symptoms like mild burning, itching or tingling are seen in approximately 50% of patients prior to appearance of recurrent lesions (in recurrent disease).
Symptoms less severe in recurrent disease (less lesions, heal faster, milder symptoms)
what are the diagnostic tests for genital herpes?
virologic
type specific (hsv1 or2) serology tests
what are the virologic tests used for genital herpes?
viral cell culture
NAAT(pcr)
to identify hsv dna from genital lesions
what is the purpose and indication for type-specific tests for genital herpes?
to test for HSV antibodies = hsv-2 atb = anogenital infection
not recommended for the first episode as takes 6-8weeks for antibodies to develop and serological detection
when best to initiate antiviral tx for genital herpes?
within 72hours
what is the supportive care for genital herpes
1) Warm saline bath relieves discomfort
2) Symptoms management –analgesia, anti-itch
3) Good genital hygiene to prevent superinfection
4) Counseling regarding natural history, e.g., it is a chronic lifelong condition with possible recurrences
treatment regimen for 1st episode of genital herpes?
include serious illness
acyclovir
PO 400mg TDS for 7–10 days
OR
IV 5-10 mg/kg q8h x 2-7 days, complete with PO for a total 10 days (for severe disease or complications that requires hospitalisation)
or
valacyclovir
PO 1g BD for 7–10 days
counselling for acyclovir
Counselling:
Take without regard to food, after food if GI upset. SE: Malaise, headache, NVD.
Maintain adequate hydration to prevent crystallisation in renal tubules.
moa of acyclovir
inhibit viral synthesis and replication by inhibiting viral dna polymerase
how to manage recurrent genital herpes?
Antiviral as Chronic Suppressive or Episodic Therapy
Choice is based on patient’s preference
counselling for valacyclovir
Counseling: Per acyclovir including hydration. Headache is main SE.
pros of chronic suppression therapy for genital herpes?
many patients report no symptomatic outbreaks
reduces the frequency of recurrences by 70%–80% in patients who have frequent recurrences (i.e.>6 recurrences per year)
hence improved quality of life
established long-term safety & efficacy
decr risk of transmission (in combination with consistent condom use and abstinence during recurrences)
regimen for chronic suppression therapy for genital herpes?
acyclovir 400mg BD
or
valacyclovir 1g OD
(can go down to 500mg OD if patients <10 recurrences per year)
or
famicyclovir 250mg BD
cons of chronic suppression therapy for genital herpes?
Cost
Compliance
what is the duration of chronic suppressive therapy for genital herpes
patients to discuss with physician on length of therapy as recurrence diminishes over time
note that patients with complicated disease e.g., disseminated disease (encephalitis, meningitis, keratitis) OR immunocompromised may require indefinite therapy
pro of episodic therapy for genital herpes?
Shorten duration and severity of symptoms
Less costly vs chronic suppression
Patient more likely to be compliant
con of episodic therapy for genital herpes?
Requires initiation of therapy within 1 day of lesion onset or during the prodrome that precedes some outbreaks
Does not reduce risk of transmission
counselling for genital herpes
Educate concerning the natural history of the disease
Encourage them to inform their current and future sex partners
Sexual transmission of HSV can occur during asymptomatic periods.
All persons with genital herpes should remain abstinent from sexual activity with uninfected partners when lesions or prodromal symptoms are present.
The risk of HSV sexual transmission can be decreased by the daily use of valacyclovir or acyclovir by the infected person.
Recent studies indicate that latex condoms, when used consistently and correctly, might reduce the risk for genital herpes transmission.
Risk for neonatal HSV infection
Increased risk for HIV acquisition
regimen for episodic therapy for genital herpes?
PO acyclovir 800mg BD x5 days
or 800mg TDS x2 days
OR
PO valacyclovir 500mg OD x 5 days
management of sex partners for genital herpes?
Symptomatic sex partners should be evaluated and treated in the same manner as patients who have genital lesions.
Asymptomatic sex partners of patients who have genital herpes should be questioned concerning histories of genital lesions, and encouraged to examine themselves for lesions and seek medical attention early if lesions occur. May be offered type-specific serologic testing for HSV-2.
PK of acyclovir vs valacyclovir
BA 10-20% vs 50% (valacyclovir)
both t1/2 = 3h
when to initiate episodic therapy
during prodromal symptoms or within 1 day of lesion onset
