Sexually transmitted infection

Introduction

• Signs and symptoms can be subtle so need high index of suspicion
• 13-24yo; pregnant women and MSM are at higher risk
• The 5P’s (CDC)
  • Partners – Sexually active now/ever, how many recent partners, men/women/both?
  • Prevention of pregnancy – Trying to conceive, any form of contraception?
  • Protection from STI – Any protection used, what kind, when
  • Practices – What kind/s of sexual contact have you had?
  • Past history of STI – Ever diagnosed/treated, recurring symptoms or diagnoses, ever been tested for STI/HIV, partner ever tested/diagnosed/treated

General recommendations

• If STI suspected – Azithromycin 1g PO stat and in 7 days + Ceftriaxone 500mg IV stat + Metronidazole 400mg PO BD for 14 days (Trichomonas)
• Always obtain pregnancy test
• If one STI suspected, screen for HIV/syphilis/hepatitis
• Educate and arrange follow-up
• Advise that partner must seek treatment before re-engagement in sex

Urethritis, cervitis and/or discharge

• Gonorrhoea
• Chlamydia
• Trichomoniasis
• Ureaplasma urealyticum
• Mycoplasma genitalium
• HSV
• Adenovirus

Urethritis, cervitis and/or discharge

• Chlamydia
  • Clinical
    • Frequently asymptomatic, especially in women
    • In men can cause urethritis, epididymitis, proctitis, Reiter’s
    • Women tend to have asymptomatic cervicitis, vaginal discharge, intermenstrual spotting and dysuria
    • Complications in women include PID, ectopic pregnancy and infertility
  • Diagnosis
    • Men
      • First-pass urine PCR >90% sensitive and 99% specific
      • Take anal and pharyngeal swab in MSM (even if asymptomatic – can self-collect)
    • Women
      • Endocervical swab PCR
      • Self-collected vaginal swab PCR (2^nd best)
      • First pass urine PCR not as sensitive in women and only indicated if above not possible
      • Anorectal swab if patient has had anal sex or has anorectal symptoms (can self-collect)
  • Treatment
    • Azithromycin 1g PO now and in 7 days
    • Doxycycline 100mg BD for 7 days
    • Refer partners within last 60 days for testing
    • Avoid sexual contact for 7 days from treatment completion and symptoms resolved
    • Encourage women to be re-tested at 3 months due to high rate of recurrence

• Gonococcal
  • In women mostly asymptomatic and often co-existing Chalmydia
  • If symptomatic, women usually present with vague lower abdominal pain and mucopurulent cervicitis after 7-14 day incubation period
  • 80-90% of men develop symptoms within 14 days with dysuria, penile discharge, epididymitis or prostatitis
  • Can cause proctitis and can be isolated from pharynx (but rarely causes pharyngitis itself)
  • Diagnosis
    • Men
      • First pass urine PCR if no discharge. If MSM anal and pharyngeal swabs for PCR + culture even if asymptomatic
      • Urethral swab culture if discharge present
    • Women
      • Endocervical swab PCR + culture if discharge present
      • Self-collected vaginal swab PCR + culture if not examined
      • First pass urine PCR only if above not available
      • Pharyngeal swab PCR + culture if oral sex
      • Anorectal swab PCR + culture if anal sex or symptoms
    • NAAT not validated for non-genital sites
    • Gonococcal culture is highly specific but not as sensitive as NAAT and allows antimicrobial sensitivity patterns

• Non-gonococcal urethritis
  • Alternative pathogens such as Ureaplasma urealyticum, Mycoplasma genitalium, HSV and adenovirus are more commonly seen in older men
  • Specific tests not indicated for U. urealyticum or M. genitalium
  • Trichomoniasis
    • Flagellated protozoan causing disease mostly in women
    • Should be routinely screened via first pass urine PCR in men or FPU/high-vaginal swab in women
    • Associated with high prevalence of coinfection with other STI’s, especially HIV
    • Ranges from asymptomatic to severe PID
    • If symptomatic, typically malodorous, thin watery discharge, vulvar irritation, burning, pruritic, dysuria, urinary frequency, dyspareunia and lower abdo pain
    • Symptoms often worse during menstruation
    • Classic yellow-green frothy discharge is rare
    • Examination usually yields vulvar inflammation, punctate cervical haemorrhages
    • May present in men as urethritis
    • Treatment – Metronidazole 400mg BD for 14 days + TREAT PARTNERS TO PREVENT RE-INFECTION + referral of partner to STI clinic due to high rates of co-infection

Disseminated gonococcal infection

• Pustular or petechial acral skin lesions on an erythematous base, asymmetrical arthralgia, tenosynovitis or septic arthritis and fever
• Seen in 3% of gonorrhoeal cases
• Two syndromes:
  • Triad of tenosynovitis, vesiculopustular rash and polyarthralgia
  • Purulent arthritis without skin lesions
  • May have cross-over
• Tenosynovitis is uncommon in other forms of infectious arthritis
• Rash described as acral (dorsal surface of feet/ankles or wrist/hands
• DDx
  • Meningococcal arthritis
  • Hep B (urticarial rash and polyarthritis)
  • Post-streptococcal arthritis (transient non-pustular rash)
  • Rheumatoid arthritis
  • Psoriatic arthritis
  • Reactive arthritis
  • Acute HIV infection
  • Secondary syphilis (palm and sole involvement)
  • Lyme disease

• Disseminated gonococcaemia
  • BC positive in 4-70% of cases (more likely if tenosynovitis, dermatitis and polyarthralgia as likely bacteraemic in this stage)
  • Mucosal site swabs – Often positive despite no symptoms at these sites
  • Synovial fluid – Only positive in purulent gonococcal arthritis in 50% of cases. Even less likely if arthritis/tenosynovitis/dermatitis
  • Pustular skin lesion samples – Yield only 105 positive culture
• Treatment
  • Ceftriaxone 500mg IV stat
  • Treat disseminated disease with Ceftriaxone 2g IV daily for 1-2 days then change to augmentin BD for total 14 days

Reiter’s syndrome

• Reactive arthritis
• Usually presents as acute asymmetric oligoarthritis 2-6 weeks post-dysentery or venereal disease
• Mostly lower extremities
• +- psoriatic-type eruption (but NOT petechial/maculopapular)
• Classical triad is rarea

Genital ulcers

• Syphilis
• Herpes simplex
• Donovanosis (Granuloma inguinale)
• Chancroid
• Lymphogranuloma venereum

Genital ulcers

Syphilis

Introduction

• Caused by spirochaete Treponema pallidum.
• Nicknamed the great imitator
• Transmitted by direct contact with syphilitic ulcers or by infected blood through microtrauma e.g. sexual intercourse or IVDU
• Rising incidence, especially in IVDU

Classification

• Primary
  • Painless chancre with indurated borders at the point of entry
  • Can be easily missed, especially if inside vagina/rectum, mouth
  • Non-tender lymphadenopathy is common
  • Incubation time 10-90 days (mean 21 days), lesions appear at 3-6 weeks
  • Typically on genitals/perianal area, mouth or lips
  • Resolves spontaneously over a few weeks
• Secondary
  • 3-6 weeks after primary stage with non-specific sore throat/malaise and rash on trunk and flexor surfaces, spreading to palms and soles
  • Non-itchy, dull red-pink and papular rash
  • May also have alopecia
  • Condylomata lata intertrigenous rash can also occur
  • Can also present with hepatitis, AKI, cranial nerve palsies, ocular signs, meningitis and arthritis
  • Rash resolves spontaneously
• Latent period
  • Between secondary and tertiary clinical stages
  • May last years
  • Asymptomatic and relies on serology for diagnosis
  • Early phase (first 1-2 years)
    • Highly infectious and can pass to sexual partners or vertically
  • Late phase (>1-2 years)
    • Significantly reduced infectivity
    • Can still pass vertically
• Tertiary or latent
  • Develops in 30% of patients after secondary syphilis
  • Occurs 3-20 years after initial infection
  • Granulomatous (gummata), meningitis, dementia, neuropathy (tabes dorsalis) and thoracic aneurysm
  • Very uncommon
• Congenital
  • Miscarriage, stillbirth or congenital disease
  • Early congenital (first 2 years of life)
    • Similar to secondary syphilis in first weeks of life
  • Late congenital
    • Chronic interstitial keratitis, deafness, bony disease, typical facial appearance and CNS disease
    • Classic Hutchinson incisors (spiral), frontal bossing, saddle nose, bowed sabre shins and swollen knees (Clutton joints)

Diagnosis

• Serology
  • VDRL and rapid reagin tests detect non-specific antibodies to cardiolipins released in infection and are used as screening, detect disease activity and response to treatment
    • Not positive until 1-4 weeks after chancre arises
    • Must confirm with Treponema pallidum-specific antibody assay
  • Nontreponemal antibody tests (VDRL, rapid reagin) are 100% sensitive and specific in secondary syphilis
  • Treated patients end up with negative nontreponemal antibody testing and these non-specific tests are used as a guide to treatment effect
  • Treated patients maintain positive specific Treponemal antibody assays for life
  • False positive serology occurs in IVDU, autoimmune diseases, pregnancy and older age
• PCR testing
  • This is the key to early diagnosis of primary syphilis. Swab any potential ulcer.
• Treatment
  • Primary and secondary – Penicillin G 2.4 million units stat
• Jarish-Herxheimer reaction
  • Mostly in early syphilis treatment with acute febrile reaction, headache, myalgia within 24 hours of therapy
• Treat sexual partners from last 90 days
• Treatment of tertiary syphilis
  • Pen G 2.4 million IU IM weekly for 3 weeks

HSV

• Most genital infections are HSV-2
• 10-25% of infections likely asymptomatic with ongoing shedding
• Clinical
  • Prodrome 2-24 hours of itch, burn, regional pain
  • Constitutional headache, fever, painful inguinal lymphadenopathy
  • Papules and vesicles on erythematous base with erosion over hours/days
  • Completely heal in 3 weeks and viral shedding continues for 10-12 days from onset of rash
  • Recurrent outbreaks are usually milder
• Diagnosis
  • Clinical. If uncertain, vesicle fluid PCR
  • Viral shedding is intermittent so false negative is fairly common
• Treatment
  • Hastens recovery but does not cure. Reduces symptoms, period of viral shedding, decreases pain and constitutional symptoms
  • First episode – Acyclovir 400mg TDS for 7-10 days or valaciclovir 1g BD
    • For proctitis or oral lesions use 400mg 5x daily for 7-10 days
  • Episodic recurrence – Valaciclovir 500mg daily for 5 days
    • Begin within 24 hours
  • Suppressive therapy indicated if >6 episodes per year

Chancroid

• Haemophilus ducreyi causes painful genital ulcers with lymphadenitis
• Sporadic male outbreaks
• Clinical – Painful erythematous papule that becomes pustular with yellow-gray necrotic exudates on base. Painful inguinal lymphadenopathy arises 1-2 weeks later with gradual transition into a pustular bubo
• Diagnosis – Clinical
• Treatment – Azithromycin 1g PO stat

Lymphogranuloma venereum

• C. trachomatis L1-3
• Painless primary chancre lasts only 1-3 days with subsequent unilateral lymphadenopathy at 1-3 weeks and progression to suppurative lymphadenopathy
• Diagnosis is clinical
• Treatment – Doxycycline for 21 days
• Untreated cases resolve over 8-12 weeks

Granuloma inguinale (Donovanosis)

• Klebsiella granulomatis
• Gram-negative intracellular bacterium
• Subcutaneous nodule on penis or labia, progressing to painless ulcers that are beefy red and bleed easily
• Subcutaneous granulomas mimic lymphadenopathy
• Diagnosis is clinical
• Treatment – Doxycycline for 3 weeks stops progression but longer treatment to allow complete healing

Genital warts

• Flesh-coloured cauliflower-like projections
• 1-8 month incubation period
• May coalesce to form condylomata acuminate
• Diagnosis is clinical
• GP management with multiple options
• Does not alter fertility or indicates oncogenic certainty
• Preventable with Gardasil (HPV 16, 18 [oncogenic] and 6 ,11 [warts])

Prophylaxis after sexual assault

• Take all forensic and culture specimens
• HIV/HCV/HBV/Syphilis serology
• Single dose Ceftriaxone 500mg IM, Metronidazole 2g PO and azithromycin 1g PO (repeat in 1 week)
• HepB vaccine for those not immunised
• Consider HIV PEP
• Consider emergency contraception
• Repeat evaluation for STI in 1-2 weeks and repeat HIV testing depending on risk profile

Emergency contraception

• Postinor 1 stat dose = Levonorgestrel 1.5mg
• Will prevent 85% of expected pregnancies if given within 72 hours
• The sooner it is taken, the more effective
• Give to all women post-sexual assault unless on excellent contraception i.e. Mirena
• Ensure not pregnant already

Last Updated on October 6, 2021 by Andrew Crofton