STIs Flashcards
Overgrowth of what organism is commonly found in Bacterial Vaginosis (BV)
anaerobic organisms e.g. Gardnerella vaginalis
Is vaginal pH low of high in BV?
Raised
Colonisation with anaerobic organisms = fall in lactic acid producing aerobic lactobacilli
=> higher vaginal pH.
Features of BV
vaginal discharge: ‘fishy’, offensive
asymptomatic in 50%
only occurs in sexually active women, but is not sexually transmitted
Criteria for BV (need 3/4 for diagnosis)
- thin, white discharge
- clue cells on microscopy
- vaginal pH > 4.5
- positive whiff test (addition of potassium hydroxide results in fishy odour)
Management of BV
- Asymptomatic
- Tx not req’d - Symptomatic:
- oral metronidazole 5-7 days
- Alternatives: topical metronidazole/ clindamycin
Risk of BV in pregnancy
increased risk of:
- preterm labour
- low birth weight
- chorioamnionitis
- late miscarriage
Organism which causes chlamydia
Chlamydia trachomatis
Incubation period of chlamydia
7-21 days
Clinical features of chlamydia
asymptomatic
women: cervicitis (discharge, bleeding), dysuria
men: urethral discharge, dysuria
Complications of chlamydia
epididymitis
pelvic inflammatory disease
endometritis
increased incidence of ectopic pregnancies
infertility
reactive arthritis
perihepatitis (Fitz-Hugh-Curtis syndrome)
Ix for chlamydia
Nuclear acid amplification tests (NAATs)
Females - vulvovaginal swab
Males - first void urine
Ideally when should testing for chlamydia be carried out
2 weeks after a possible exposure
Management of chlamydia
1st Line:
- doxycycline (7 day course)
2nd Line:
- Azithromycin 1g OD for one day then 500mg OD for 2 days
- Partner/contact tracing
Who should be contacted in chlamydia contact tracing?
men with urethral symptoms:
- all partners from 4 wks prior to symptom onset
for women and asymptomatic men:
- all partners from the last 6 months
What virus group s responsible for genital herpes?
HSV
Symptoms of genital herpes
- painful ulcers
- dysuria
- pruritis
- systemic symptoms e.g. headache/fever
- tender inguinal lymphadenopathy
- urinary retention
Primary infection with genital herpes is often more severe than recurrent episodes. TRUE/FALSE?
TRUE
Diagnostic investigations to look for genital herpes
nucleic acid amplification tests (NAAT)
HSV serology
Management of genital herpes
- analgesia
- topical anaesthetic e.g. lidocaine
- oral aciclovir
If a lady who is >28 weeks pregnant develops a Primary genital herpes infection, what type of delivery is preferable at term?
elective caesarean section
women with recurrent herpes during pregnancy should be reassured that risk of transmission to their baby is low. TRUE/FALSE?
TRUE
treat with suppressive therapy even during pregnancy
What are condylomata accuminata more commonly known as?
Genital warts
What virus is responsible for genital warts?
human papillomavirus HPV
- types 6 & 11
A patient presents with new lesions appearing on their genitals. They appear as small (2 - 5 mm) fleshy protuberances which are slightly pigmented
may bleed or itch. What are these?
Genital warts
Management of genital warts
1st Line:
- topical podophyllum (if multiple)
- cryotherapy (if single lesion)
2nd Line:
- imiquimod
Genital warts are often resistant to treatment. TRUE/FALSE?
TRUE
- recurrence is common
Organism causing gonorrhoea
Neisseria gonorrhoeae
(Gram-negative diplococcus)
Apart from genitourinary infection, where else can gonorrhoea affect?
rectum and pharynx
What is the incubation period of gonorrhoea?
2-5 days
Clinical features of gonorrhoea
Males:
- urethral discharge
- dysuria
Females:
- cervicitis => vaginal discharge
Rectal and pharyngeal gonorrhoea infection is usually asymptomatic. TRUE/FALSE?
TRUE
Why is reinfection with gonorrhoea common?
- no vaccine
- antigen variation
Local complications of gonorrhoea
- urethral strictures
- epididymitis
- salpingitis => may lead to infertility
Management of gonorrhoea
1st line:
- IM ceftriaxone 1g
If sensitivities to cipro-
=> oral ciprofloxacin 500mg
3 features of disseminated gonococcal infection
- tenosynovitis
- migratory polyarthritis
- dermatitis (lmaculopapular or vesicular)
Complications of gonococcal arthritis
septic arthritis
endocarditis
perihepatitis (Fitz-Hugh-Curtis syndrome)
Incubation period for pubic lice
5 days
Typical symptoms/signs of pubic lice
- Itching worse at night
- ‘black/rust-coloured powder’ in underwear
- Excoriation marks
- blue macules
Investigation of pubic lice
- Microscopic evaluation of hair to identify presence of lice/ eggs
- full sexual health screen
Management of pubic lice
- wash clothing and bed linen
- malathion 0.5% OR permethrin 1%
- re-applied after 3-7 days (lice and eggs at different stages of their life cycle)
- nit-combs
Who should be contact traced after a case of pubic lice?
- any sexual partners within the past 3 months
Painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement.
The ulcers typically have a sharply defined, ragged, undermined border.
Chancroid
(Haemophilus ducreyi)
- tropical disease
Stage 1: small painless pustule which later forms an ulcer
Stage 2: painful inguinal lymphadenopathy
Stage 3: proctocolitis
Lymphogranuloma venereum (LGV)
- caused by Chlamydia trachomatis.
Treatment of lymphgranuloma venereum
doxycycline
(same tx as for chlamydia)
What organism causes syphilis
Treponema pallidum
(spirochaete)
Incubation period in syphilis
9-90 days
Features of PRIMARY syphilis
- chancre
- local, non-tender lymphadenopathy
Why may the typical syphilis chancre not be visible in females
lesion may be on the cervix
Typical features of SECONDARY syphilis (6-10 weeks post infection)
systemic symptoms:
- fevers
- lymphadenopathy
- rash on trunk, palms, soles
- buccal ‘snail track’ ulcers
- condylomata lata (painless, warty lesions on the genitalia )
Typical features of TERTIARY syphilis
- gummas (granulomatous lesions of the skin and bones)
- ascending aortic aneurysms
- paralysis
- spinal cord degeneration
- Argyll-Robertson pupil
Features of congenital syphilis
- blunted upper incisor teeth (Hutchinson’s teeth), ‘mulberry’ molars
- rhagades (linear scars at the angle of the mouth)
- keratitis
- saber shins
- saddle nose
- deafness
Investigation for syphilis
non-treponemal test + treponemal test
Describe how non-treponemal tests work
- reactivity of serum from infected patients to a cardiolipin-cholesterol-lecithin antigen
examples include:
- rapid plasma reagin (RPR)
- Venereal Disease Research Laboratory (VDRL)
Give examples of treponemal tests for syphilis
TP-EIA (T. pallidum enzyme immunoassay)
TPHA (T. pallidum HaemAgglutination test)
- these are qualitative => results are either ‘reactive’ or ‘non-reactive’
Causes of false positive non-treponemal tests
pregnancy
SLE, anti-phospholipid syndrome
TB
leprosy
malaria
HIV
Positive non-treponemal test + positive treponemal test
active syphilis infection
Positive non-treponemal test + negative treponemal test
false-positive result e.g. due to pregnancy or SLE
Negative non-treponemal test + positive treponemal test
successfully treated syphilis
Management of syphilis
IM benzylpenicillin
(or doxycycline)
How do we monitor response to syphilis treatment?
Monitor non-treponemal titres
Fever, rash, tachycardia after the first dose of antibiotic in syphilis
Jarisch-Herxheimer reaction
What type of organism is trichomonas vaginalis
highly motile, flagellated protozoan parasite
Features of trichomonas infection
- offensive yellow/green discharge
- vulvovaginitis
- strawberry cervix
- vaginal pH > 4.5
- men usually asymptomatic but may cause urethritis
Investigation findings in trichomonas infection
microscopy of a wet mount shows motile trophozoites
Treatment of trichomonas
oral metronidazole for 5-7 days
