Sexually Transmitted Infections Flashcards
What are important general principles when managing a person with a STI?
Screen for other infections there is often co-infection.
Regular sexual partners should be traced and screened.
Contact tracing of any partners.
Educate about the risks of unsafe sex and that barrier contraception is the only way of reducing the risk of contracting STI’s.
What are the risk factors for contracting STI’s?
Multiple partners Concurrent partners Non use of barrier protection Other STI's Under 25's Involvement in sex industry
What causes chlamydia, what symptoms does it cause and how is it diagnosed?
It is caused by Chlamydia trachomatis.
It is often asymptomatic.
Females:
Intermenustral/post coital bleeding
Vaginal discharge
Dysuria
Males:
Dysuria
Urethral discharge
Nucleic acid amplification tests (NAATs) on a urine sample in men and women.
If a women is being examined a endocervical swab is used.
What are the alternative presentations of chlamydia?
Men:
Epidymo-orchitis
Reactive arthiritis
Conjunctivitis
What are the complications associated with chlamydia?
PID
In pregnancy:
Preterm premature rupture of membranes (PPROM)
Neonatal conjunctivitis and pneumonia
What is the treatment of chlamydia?
Azithromycin 1g single dose
Or
Doxycycline 7 days course
What causes gonorrhoea and what symptoms does it cause and how is it diagnosed?
Neisseria gonorrhoeae
Symptoms:
Purulent discharge and dysuria
Endocervical swabs + NAAT (nucleic acid amplification test)
Urethral swabs if symptomatic in men otherwise NAAT is sufficient
Swabs and microscopy are important to look for antibiotic resistance
How is gonorrhoea treated?
IM ceftriaxone + azithromycin PO (single dose of both)
If penicillin allergic:
Spectinomycin + azithromycin PO
Multi resistant strains are now resistant to ceftriaxone
What are the complications of gonorrhoea?
Local infection spread (epididymis, prostate)
Urethral scarring
PID
In pregnancy:
PPROM
Chorioamnionitis
Ophthalmia Neonatrum (can cause blindness)
What causes HSV and what symptoms does it cause and how is it diagnosed?
Herpes simplex virus 1 (oral) and 2 (genital) but there is crossover.
Primary infection presents with:
- Itchy/tingly prodrome
- Flu like illness
- Vulvitis
- Characteristic small fluid filled vesicles on the vulva
Recurrent attacks usually lack the systemic affects and just present with the vesicles.
Diagnosis is usually clinical but PCR testing of the vesicular fluid is gold standard.
How is HSV treated?
No curative treatment.
Symptomatic relief and analgesia is given.
Acyclovir is given for immunocompromised individuals.
Condoms or abstinence whilst symptomatic as it is contagious at this point.
What are the potential complications of HSV infection?
Disseminated disease including meningitis.
Nerve damage.
Increases HIV transmission
Pregnancy:
If primary infection is within 6 weeks of labour then mother should have a CS and herpes can spread to the child causing disseminated disease which carriers a higher mortality rate.
What organism causes syphilis and what symptoms can it cause?
Trepenoma pallidum
Primary syphilis:
Painless genital ulcer + inguinal lympathendopathy. May also be found on the anus or around the mouth.
Secondary syphilis:
Occurs within 2 years on primary infection can cause:
-Generalised polymorphic rash affecting the hands and feet.
-Generalised lympathendopathy
-Anterior uveitis
-Genital warts
Tertiary syphilis:
Occurs up to 40 years after primary infection.
-Neurosyphilis: dementia/personality change, dorsal column dysfunction
-Cardiac syphilis: aortic aneurysm
-Gummata syphilis: Inflammatory fibrous nodules or plaques, which may be locally destructive.
Can occur in any organ but most commonly affect bone and skin.
How is syphilis tested for?
Primary lesion smear may show sphirochaetes on dark field microscopy
Specific treponemal enzyme immunoassays for screening can be done, should then be confirmed using another test.
What is the treatment for syphilis?
Benzylpenicillin IM
OR
erythromycin/doxycycline for 14 days if penicillin allergic
What are the complications of syphilis?
Development of tertiary syphilis.
In pregnancy:
Miscarriage
Premature delivery or still birth
Congenital syphilis
What is Condylomata Acuminata?
Also known as genital warts.
It is caused by HPV.
It is a very common virus which many people carry it is usually asymptomatic but sometimes it can present as anogenital warts.
This is due to HPV 6 + 11.
HPV 16 + 18 are associated with neoplasm.
Diagnosis is clinical only biopsy if it looks abnormal (flat/pigmented/ulcerated/indurated)
How our genital warts treated/prevented?
Topical podophyllin
Cryotherapy/cautery/excision
Recurrence rate is high.
Warts are prevented with adolescent vaccination to all girls: the vaccine covers HPV 6, 11, 16 and 18.
What causes trichomonas, how is it diagnosed and what symptoms does it cause?
Caused by protozoan.
It is often asymptomatic but can cause:
- Frothy offensive smelling discharge
- Vulval itching and soreness
- Dysuria
Strawberry cervix
Investigated with a high vaginal swab, as sensitivity is poor follow up with wet microscopy is recommended.
How is trichomonas treated?
Metronidazole
Which swabs are routinely taken, where are they taken and what do they test for?
High Vaginal: Trichomonas, bacterial vaginosis
Endocervical: Chlamydia and Gonorrhoea
A patient presents with a genital ulcer, what are your differential diagnoses?
HSV (painful)
Syphyllis (painless)
All rare in western countries more common in asia and africa:
- Chancroid (Haemophilus ducreyi)
- Lymphogranuloma verenulum (rare subtype of chlamydia)
- Donovanosis (klebsiella infection causing genital ulcers)
A patient presents with vaginal discharge what are your differentials?
Physiological
Non STI:
- BV
- Candidiasis
STI:
- Trichomonas
- Chalmydia
- Gonorrhoea
Non infective:
- Malignancy
- Fistulae
- Retained foreign body (e.g. pessary ring increases discharge)
What are the physiological causes of vaginal discharge?
Oestrogen related: puberty/pregnancy/COC
Cycle related: Maximal mid cycle and premenstrual
Sexual: Arousal/intercourse
How can you distinguish between vaginal discharge in the following conditions: BV, Candidiasis, Trichomonas, Malignancy?
BV: Grey/white, fishy odour, raised pH
Candidiasis: White (cottage cheese), normal odour and pH
Trichomoniasis: Grey-green, smelly, raised pH
Malignancy: Red-brown discharge, smelly, variable pH
