STIs (Gonorrhea, Chlamydia, Syphilis) Flashcards
Under IDA, notification should be done within ___h of diagnosis
What is the purpose of notifying?
What data must be notified?
72h
Notification purpose: monitoring and evaluating national control programmes, NOT for detection/contact tracing
Only demographic data (age, gender, ethinicity, nationality) requied for epidemiologic analysis
Partner notification is only mandatory for _____
HIV/AIDS
What are the modes of transmission of STIs?
- Sexual contact
- Direct contact of broken skin with open sores, blood, genital discharge
- Receiving contaminated blood
- Infected mother to child (pregnancy, childbirth, breastfeeding)
Classify the STIs into the following categories:
- Transmitted during pregnancy (across placenta, in utero)
- Transmitted during childbirth (maternal blood contact)
- Transmitted during breastfeeding
- Pregnancy: Syphilis, HIV
- Childbirth: Chlamydia, Gonorrhea, HSV, HIV
- Breastfeeding: HIV
Can STIs be transmitted through kissing?
Not in dry kissing
But may in deep wet kissing as gonorrhea, chlamydia, syphilis, herpes can be present in the mouth/throat of the infected person
What are the risk factors for STIs?
- Unprotected sexual intercourse (condom)
- Number of sexual partners/sexual contact with people who have multiple sexual partners
- MSM
- Prostitution (CSW)
- Illicit drug use - contaminated needle, risky sexual behaviour
What are some individual prevention methods for STIs?
- Abstinence, reduction of number of sexual partners
- Barrier contraceptive (condoms)
- Avoid drug abuse, avoid sharing needles
- Pre-exposure vaccination (for HPV, Hep B)
- Pre- and Post-exposure prophylaxis (for HIV only)
Why is the management and prevention of STIs important?
- Reduce related morbidity, progression to complicated disease
- Prevent HIV infection
- incr risk of HIV acquisition in pt w gonococcal, syphilis, and genital herpes
- Prevent serious complications in women
- STIs are main preventable cause of infertility (gonorrhea and chlamydia can damage fallopian tube and womb)
- Prevention of HPV reduces no. of women with cervical cancer, and reduces anal and rectal cancer in men
- Protect the babies
- Untreated STIs cause congenital and perinatal infections in the neonates, premature deliveries, neonatal death or stillbirth
Compare the incubation periods of the various STIs
Short incubation period (2 days to 3 weeks)
- Gonorrhea
- Chlamydia
- Genital Herpes
Long incubation period (2 weeks to months)
- Syphilis
Longer incubation period (several years)
- HIV
[GONORRHEA]
What bacteria causes gonorrhea?
How does it appear on gram stain?
Neisseria gonnorhoeae
Intracellular gram-negative diplococci (pink)
[GONORRHEA]
Transmission via?
- Sexual contact
- During childbirth
[GONORRHEA]
How is it diagnosed?
- Gram-stain of genital discharge
- Culture
- NAAT (urine PCR)
[GONORRHEA]
Uncomplicated gonorrhea affects the __________ area
If left untreated, can infect various sites and cause:
Uncomplicated urogenital gonorrhea
If left untreated:
- Urethritis
- Cervicitis
- Proctitis
- Pharyngitis
- Conjunctivitis
- Disseminated
[GONORRHEA]
Individuals may be asymptomatic.
If symptomatic, what is the presentation of uncomplicated urogenital gonorrhea for males and females respectively?
MALES:
- Purulent urethral discharge
- Dysuria
- Urinary frequency
FEMALES:
- Mucopurulent vaginal discharge
- Dysuria
- Urinary frequency
[GONORRHEA]
What are some complications that can arise from untreated gonorrhea? (males and females respectively)
MALES:
- Epididymitis
- Prostatitis
- Urethral stricture
- Disseminated disease
FEMALES:
- Pelvic inflammatory disease
- Ectopic pregnancy (since gonorrhea can affect the fallopian tube)
- Infertility
- Disseminated disease
In BOTH:
- Disseminated disease: skin lesions, tenosynovitis, monoarticular arthritis
[GONORRHEA]
Which class of antibiotics is no longer used in the management of gonorrhea due to increasing resistance?
Fluoroquinolone
- increasing resistance to ciprofloxacin
[GONORRHEA]
Treatment of gonococcal infection should be accompanied by _________
Anti-chlamydia therapy
*Unless chlamydia infection has been excluded
[GONORRHEA]
What is first line for the management of uncomplicated urogenital gonococcal infections?
IM Ceftriaxone 500mg, single dose (for <150kg)
IM Ceftriaxone 1g, single dose (for >=150kg)
If Chlamydia not excluded,
+ PO Doxycycline 100mg BD x7d
[GONORRHEA]
What are the alternatives for the management of uncomplicated urogenital gonococcal infections?
- IM Gentamicin 240mg + PO Azithromycin 2g single dose
- PO Cefixime 800mg single dose (+ PO Doxycycline 100mg BD x7d)
[GONORRHEA]
Is test of cure recommended for gonococcal infection?
US CDC - not required unless symptoms persists
DSC - recommended (worried of Ceftriaxone resistance)
[GONORRHEA]
Explain the management of sex partners
- Sex partners in last 60 days should be evaluated and treated. If last exposure >60d, then treat the most recent partner
- To minimize disease transmission, abstain from sexual activity for 7 days after treatment and resolution of symptoms
- To minimize risk for reinfection, abstain from sexual intercourse until all sex partners have been treated
[CHLAMYDIA]
Chlamydia infections are caused by what bacteria?
Chlamydia trachomatis (atypical)
[CHLAMYDIA]
Transmitted via?
- Sexual contact
- During childbirth
[CHLAMYDIA]
How is it diagnosed?
NAAT (PCR - urine or genital swab)
*Recall atypicals don’t appear well on gram stains
[CHLAMYDIA]
What is the clinical presentation?
SImilar to gonorrhea, but possibly milder
- Purulent discharge, dysuria, urinary frequency
- Can infect various sites, and cause complications as per gonorrhea (e.g., infertility, ectopic pregnancy in women, epididymitis, prostitis in men, disseminated disease)
[CHLAMYDIA]
What is the first line management?
PO Doxycyline 100mg BD, x7d
[CHLAMYDIA]
What are the alternative management?
PO Azithromycin 1g single dose
OR
PO Levofloxacin 500mg once daily, x7d
[CHLAMYDIA]
Explain the following:
- Why Doxycyline as first line
- Why Erythromycin is not recommended
- Why other FQs are not recommended
- Doxycyline is first line due to better cure rates
- Erythromycin is not recommended due to GI SEs that reduce adherence (gastric distress and motility - it is a motilin agonist)
- Levofloxacin is the only FQ effective against Chlamydia
[CHLAMYDIA]
Azithromycin may be used as first time if adherence is a concern (since it is single dose)
Explain the PK reasons as to why Azithromycin can be given 1g as a single dose for Chlamydia
Azithromycin:
- Long intracellular half-life (60-70h, 68h) vs serum half life (12h)
- Drug able to stay in WBC for next 3 days
[CHLAMYDIA]
Is test of cure required? Why or why not?
Not required as treatment for Chlamydia is highly effective
Less concerns of resistance etc.
Only required for specific concerns such as pregnancy, non-adherence, or if symptoms persist
[CHLAMYDIA]
Explain the management of sex partners
- Sex partners in last 60 days should be evaluated and treated. If last exposure >60d, then treat the most recent partner
- To minimize disease transmission, abstain from sexual activity for 7 days after single dose treatment or until completion of a 7 day regimen, and resolution of symptoms
- To minimize risk for reinfection, abstain from sexual intercourse until all sex partners have been treated
[SYPHILIS]
Syphilis is caused by which bacteria?
Treponema Pallidum (spirochete)
[SYPHILIS]
Transmitted via?
- Sexual contact
- During pregnancy (transplacental/in utero)
[SYPHILIS]
There are various stages of syphilis based on the clinical presentation.
Briefly describe each stage.
- Primary - more localised (painless ulcers/chancre at genital, anus, mouth) (may also have multiple, painful lesions)
- Secondary - more systemic (hematogenous and lymphatic spread can cause skin rash, mucocutaneous lesions, patchy alopecia, lymphadenopathy)
- Latent (early <1y, late >1y) - asymptomatic, internal organs affected, picked up by serology testing, determine based on pt history taking
- Tertiary - involve heart, eye, bones, joints (a/w cardiac involvement, blindness, gummatous lesions in joints - impaired movement)
- Neurosyphilis - CNS involvement (cognitive dysfunction, S&S of meningitis and stroke)
[SYPHILIS]
What are the two ways to diagnose syphilis?
- Darkfield microscopy of exudates from lesions (appear as wriggly spirochetes)
- 2 serological blood tests - treponemal and non-treponemal tests
[SYPHILIS]
Describe the treponemal test
Treponemal test
[E.g., T. Pallidum Haemagglutination test (TPHA), T. Pallidum Passive Particle Agglutination Assay (TPPA)]
- Uses the treponemal antigen to detect treponemal antibody
- More sensitive and specific than non-treponemal test
- Used as a confirmatory test
- Qualitative test: positive or negative result
- May remain reactive for life, not used for monitoring response to treatment
[SYPHILIS]
Describe the non-treponemal test
Non-treponemal test
[E.g., venereal disease research laboratory slide test (VDRL), rapid plasma reagin card test (RPR)]
- Uses nontreponemal antigen (cardiolipin) to detect treponemal antibodies
- Positive test indicate presence of any stage of syphilis
- Less specific, need treponemal test to confirm
- Quantitative test: result reported is the most dilute serum conc. with a positive reaction
- Antibody titres correlate with disease activity, used to monitor response to treatment (VDRL and RPR are not interchangeable)
- Non-treponemal test tItres decline after treatment, and can become non-reactive
[SYPHILIS]
Recall the 2 main antibiotics that have activity against spirochetes
- Penicillin G
- Tetracyclines
[SYPHILIS]
Explain the normal regimen for primary/secondary/early latent syphilis
IM Benzathine Penicillin G 2.4MU x1 dose
*Benzathine - distribute into storage tissue, prolonged release over a week
[SYPHILIS]
Explain the penicillin-allergic regimen for primary/secondary/early latent syphilis
PO Doxycyline 100mg BD x14d
*Counsel: take w food to reduce GI upset, take w full glass of water, remain upright for at least 30min to prevent esophagitis and heartburn, space 2h apart from multivalent ions
*SE: GI upset, photosensitivity
[SYPHILIS]
Explain the normal regimen for late latent/tertiary/unknown duration syphilis
IM Benzathine Penicillin G 2.4MU once a week x3 dose
[SYPHILIS]
Explain the penicillin-allergic regimen for late latent/tertiary/unknown duration syphilis
PO Doxycyline 100mg BD x28d
[SYPHILIS]
Explain the normal regimen for neurosyphilis
IV Crystalline Pen G 3-4MU q4h x10-14d
OR
IV Crystalline Pen G 18-24MU/day as a continuous infusion x10-14d
OR
IM Procaine Pen G 2.4MU once daily + PO Probenecid 500mg qid x10-14d
*Procaine - distribute into storage tissue, prolonged release over a day
*Probenecid inhibits renal tubular secretion of penicillin, thereby increasing its conc. and prolonging its effect
[SYPHILIS]
Explain the penicillin-allergic regimen for neurosyphilis
IV/IM Ceftriaxone 2g once daily x10-14d
*They do not share common R1 side chain, hence lower risk of cross-sensitivity
*However if there is still concern for cross-sensitivity:
- skin test to confirm penicillin allergy
- desensitization
[SYPHILIS]
What reaction might cause fever to develop within the first 24h of syphilis treatment?
Jarisch-Herxheimer reaction: acute febrile reaction accompanied by haedache and myalgia (occur within first 24h after therapy)
Antipyretics will help but not prevent
[SYPHILIS]
How to monitor for therapeutic response with syphilis treatment?
Monitoring for primary/secondary/latent:
- Quantitative VDRL/PRP at 3, 6, 12, 18, 24 months
- Treatment success = dcr of VDRL/RPR titre by at least 4 fold
Monitoring for neurosyphilis:
- CSF examination (draw via lumbar puncture) every 6 months until CSF normal (examine cell count, protein content etc.)
[SYPHILIS]
What is defined as treatment failure at 6 months for syphilis treatment?
Treatment failure at 6 months when:
- Show signs and symptoms of the disease
- Failure to dcr VDRL or RPR titre by 4 fold, or increase in titre
=> Retreat and reevaluate for unrecognized neurosyphilis
[SYPHILIS]
Explain the management of sex partners
- All at risk sexual partners should be evaluated for STIs and treated it tested positive
- Persons who receive syphilis treatment must abstain from sexual contact with new partners until syphilis lesions are completely healed (*careful assessment of response and symptoms resolution by the doctor)
