STIs 1 PT 2 Flashcards
Chlamydia: Epidemiology
- Most common reported notifiable STI in Alberta
and Canada (>75% of all reported STIs) - Most common cause of urethritis and cervicitis
in North America - Infection can involve the urogenital tract as well
as cause rectal, pharyngeal and conjunctival
infection - Similar risk factors to gonorrhea, although
females may be more affected than males - ?Females less likely to infect males
- Males? More likely to infect females?
In 2017, 8% of cases were co-infected
with gonorrhea.
Chlamydia (like gonorrhea) can similarly introduce risk of infertility and reproductive damage (via PID/etc)
Chlamydia: Etiology & Transmission
PATHOGEN: Chlamydia trachomatis (obligate intracellular
ATYPICAL bacteria)
* Chlamydial “serovars” refer to “strains” of Chlamydia
trachomatis which behave differently (might be different
species)
* Serovars A-C = cause conjunctivitis aka. trachoma
* Serovars D-K = urogenital tract infection
* Serovars L1-L3 = invasive disease, another STI called
lymphogranuloma venereum (LGV)
TRANSMISSION:
* Predominantly sexual contact via contact with sexual
fluids or direct contact, vertical transmission
* Incubation Period: 7-21 days (longer than Neisseria
gonorrheae)
All Chlamydia species are “ATYPICAL” because they HAVE NO PEPTIDOGLYCAN CELL WALL (unable to stain)
Chlamydia: Clinical Presentation & Complications
Chlamydia is more ASYMPTOMATIC than gonorrhea = ? Reason for why more prevalent as STI?
There’s dogma that potentially Gonorrhea typically causes a more mutual purulent disease with a lot more discharge than Chlamydia.
Clinically speaking, that’s totally useless, and, generally speaking, as soon as somebody has
any signs of this area, as well as pain with sex discharge from the they’re getting tested for both. Gonorrhea and Chlamydia
Chlamydia & Reactive Arthritis
Reactive arthritis is an autoimmune inflammatory response
to some infections – one of them being Chlamydia
trachomatis infections (also gonorrhea, and some GI
bacterial infections)
The classic triad of features include:
* “Can’t see” (anterior uveitis)
* “Can’t pee” (urethritis/cervicitis)
* “Can’t climb a tree” (inflammatory monoarthritis)
Usually occurs 1-6 weeks after the infection.
Treatment: antibiotics for the infection if still present, NSAIDs
for acute phase of reactive arthritis
Most cases of reactive arthritis are short lived and resolve spontaneously.
Chlamydia: Epididymo-orchitis in Males
Chlamydia (and gonorrhea) can threaten male fertility
through epididymitis and epididymo-orchitis (infection
involving BOTH the epididymis AND testes).
PRESENTATION: scrotal pain, unilateral swelling/redness
and tenderness
PATHOGENS: bacterial, in men < 35 years mostly STI
organisms (Neisseria gonorrhea, Chlamydia trachomatis,
in older men can be GNBs)
TREATMENT: antibiotics targeting these organisms (e.g.,
ceftriaxone + azithromycin) typically for 2-3 weeks\
Epididmyal abscesses can form in the vas-deferens which requires surgical incision and drainage.
Chlamydia: Diagnosis & Recognition
Diagnosis often highly suspicious via history and
physical alone (often able to express discharge in males
in acute disease) but confirmed depending on the SITE
INFECTED:
URETHRITIS / CERVICITIS:
* Urine NAT Testing for G/C (also detects Neisseria
Gonorrhea if present) – detects DEAD organism as
well!
* NAT can also be done with cervical/urethral swabs
DIFFICULT TO CULTURE! (requires special media)
Diagnosis of gonorrhea/chlamydia is SIMPLE and only requires a URINE SAMPLE!
Memorizing Antibiotic Spectra: Beta-Lactam Antibiotics
Memorizing Antibiotic Spectra: Advanced & Adjunct Agents for Gram-Positive Pathogens
Memorizing Antibiotic Spectra: Agents for BL-Resistant Gram-Negative Infections
Memorizing Antibiotic Spectra: Atypicals & Anaerobes
VLD is useful for drug-resistant G+ organisms (MRSA/VRE). Clindamycin is rarely clinically useful and justified.
Tetracyclines can be useful elsewhere, but notice macrolides = ~atypicals only, metronidazole = anaerobes only.
although our natural penicillin, like Penicillin G, that you might use for syphilis, can’t kill Chlamydia. Interestingly, amoxicillin and amox-clav have proven clinical outcome data against Chlamydia.
No need to double up on treatment. If patients have already received
a course of a Moxicillin, if they have Chlamydia
Cephalosporins nor carbapenems do not cover atypicals
Floroquinolones do cover atypicals including chlamydia
ciprofloxacin, levo, moxi
Macrolides work
- Azi 1st line
Tetracyclines work
Chlamydia: Treatment Guidelines
Urethral, Cervical, Pharyngeal Infection &
Gonorrhea test is NEGATIVE
* Non-Pregnant/Non-Lactating Adults:
Preferred:
* Azithromycin 1 gm po in a single dose, OR
Alternate:
* Doxycycline 100 mg po twice daily for 7 days
* Pregnant/Breastfeeding Individual:
Preferred:
* Azithromycin 1 gm po in a single dose, OR
Alternate:
* Amoxicillin 500 mg po three times daily for 7 days
Rectal Infection
* Adults and children ≥ 9 years of age:
Preferred:
* Doxycycline 100 mg po twice daily for 7 days
Alternate:
* Azithromycin 1 gm po in a single dose
Test of cure is recommended
Short treatment strategies with STIs… proof of concept of short duration of therapy with antibiotics?
Chlamydia: Follow-Up & Test-of-Cure
- Test of cure (TOC) for genitourinary CT is not routinely indicated
- TOC is recommended when:
- Adherence is sub-optimal
- Treatment provided is not in-line with Alberta Guidelines
- Client is prepubertal
- A non-genital site is involved
- Client is pregnant
- NAAT, is the preferred test for TOC
- should be done 3-4 weeks after treatment to avoid false-positive results
- Re-screening of all individuals infected with chlamydia is recommended after 6
months because of the risk of re-infection
TOC is less important than with gonorrhea due to very low risk of DRUG-RESISTANCE!
Trichomoniasis: A Parasitic STI
PATHOGEN: Trichomonas vaginalis (flagellated,
sexually transmitted protozoan)
TRANSMISSION:
* Sexual contact (direct contact/fluids)
* More often infects FEMALES (~20% of females
@ reproductive age); very RARELY symptomatic
in males but they can be CARRIERs
* Co-infection with G/C is common
PRESENTATION/DIAGNOSIS:
* Frothy/yellow-green vaginal discharge +/- fishy
odor, soreness, dysuria, dyspareunia
* NAT+ available for urine, microscopic testing
The treatment of trichomoniasis involves METRONIDAZOLE 2 g PO as a single dose, or 500 mg PO BID x 5-7/7
Genital warts is one of the only STIs that can be prevented by an effective vaccine.
Human Papillomavirus (HPV) & Genital Warts
PATHOGEN: Human papillomavirus (HPV) (small
dsDNA virus, oncogenic potential)
* Most common viral STI
* Lifetime risk of HPV ~75%; majority subclinical
* 1-2% life-time risk of clinically visible warts
Increased risk of cervical cancer (women) and
oropharyngeal/rectal cancer (in men more
common).
9-Valent HPV vaccines HIGHLY EFFECTIVE at
preventing urogenital cancers and anogenital
warts.
Not all HPV types are oncogenic = the most important are HPV 16 and 18, although others emerge.
Human Papillomavirus (HPV): Recognition & Diagnosis
- Routine test for virus not
available - Clinical Diagnosis
- Direct examination (+/- hand
lens) - Colposcopy for visible warts
of cervix and anus and
urethroscopy if extensive
meatal warts - Pap smears
Diagnosis is often thought to be confirmed by response to liquid nitrogen treatment.
Genital Warts: Treatment Strategies
No treatment guarantees cure of clinical lesions
* Clearance of external genital warts in 80%, cervical
warts in 90-98% cases
* No treatment eradicates HPV infection
* All suspicious lesions (e.g., rapid growth, bleeding)
should be biopsied
There is NO evidence that ANY treatment is superior to
others – the choice in treatment strategy should be based
on CLINICIAN EXPERIENCE with a specific strategy:
* Cryotherapy (application of liquid nitrogen)
* Surgical therapy (uncommon expertise)
* Home-initiated therapies
Recurrence is common – so repeated treatments are almost always necessary to some extent!
Genital Warts: Recommended Home-Initiated Treatment
The approved HOME-initiated patient therapies include:
- Podofilox 0.5% solution; applied BID x 3/7 followed by
4 days no treatment, repeating the cycle x 4 - Imiquimod 3.75% (Vyloma) – has replaced Aldara (5%)
cream; applied ONCE at BEDTIME QHS x up to 8/52 - Sinecatechins 10% ointment; apply TID until complete
clearance of warts, not longer than 16/52
Treatment DURING PREGNANCY is a special management
consideration – cytotoxic agents (like ABOVE) should NOT
BE USED IN PREGNANCY: - During pregnancy, prefer liquid nitrogen therapy OR
trichloroacetic acid (provider administered)
Instead of memorizing all treatment strategies – become comfortable with ONE, then stick to it!
Genital Warts: HPV Vaccination
HPV HAS AN APPROVED VACCINE WHICH PREVENTS
CANCER! (can you name the other vaccine which can
prevent cancer?)
The goal of the vaccination is to reduce the risk of
anogenital warts and cervical/other cancers related to
HPV.
* Should be given at age 11-12 for ALL girls and boys (as
early as age 9 if question of sexual abuse/assault)
* Eligible to receive covered if up to age 26
* Able to receive after age 26 – but public health data
after this age are lacking; reasonable if at risk!
HPV vaccination can prevent cancer. Administration is recommended to ALL patients.
