STIs and genital microbiology Flashcards
What can be done to STI test samples
Culturing
Microscopy
PCR
ELISA testing
Symptoms of urethritis?
Dysuria
Discharge
(No bladder or systemic problems)
What is dysuria
Pain on urination
Cuases of urethritis
Chlamydia
Gonorrhoea
Non-specific urethritis
Investigations in urethritis
Examine
Urethral swab (Gram and microscopy)
Urethral swab GC
NAAT
Blood for syphilis and HIV
What is NAAT
First void urine, throat and rectal swabs for chlamydia and gonorrhoea
History points for pelvic pain
- Characteristic (E.g. associated with sex or menstrual cycle)
- Query change in vaginal discharge
- Gynae and reproductive history
- Query any urinary or bowel or systemic symptoms
- Contraceptive history
- Sexual history
History points for urethral discharge
- Duration of symptoms
- Colour/Amount
- Other urinary symptoms
- Testicular symptoms
- Systemic symptoms
- Sexual history
What should be considered here:
A diagnosis of PID should be considered in any sexually active woman with recent onset lower abdominal pain associated with local tenderness on bimanual exam, in whom pregnancy has been excluded and no other cause is identified
Pelvic Inflammatory Disease
What are some risks of PID
increases risk of ectopic pregnancy 10 fold and carries a risk of tubal factor infertility of 15-20%
Management of PID
Ceftrioxone 1g IM + Doxycycline 100mg BD 2 weeks + Metronidazole 400mg BD 2 weeks
History points in vaginal discharge
- Duration
- Characteristics (Colour, Consistency, Amount)
- Associated features (Itch/Smell)
- Relation to menstrual cycle
- Any OTC treatment
- Contreceptive Hx
- Signs of upper genital tract infection
- Sexual Hx
Infective causes of vaginal discharge
- Gonorrhoea
- Chlamydia
- Trichomonas vaginalis
- Herpes simplex
- Mycoplasma genitalium
- Bacterial vaginosis
- Candida
Hormonal causes of vaginal discharge
- Puberty
- Pregnancy
- Menopause
- Physiological
- Cervical ectopic
(Also retained tampon)
Normal vaginal conditions
pH < 4.5
Lactobacilli
Lactic acid
Vaginal microbiome in bacterial vaginosis
- Semen or blood and over-washing leads to pH ≥4.5
- Death of lactobacilli
- Overgrowth of Garnella, Mobiluncus and anaerobes
Sexually transmitted causes of genital ulceration
- HSV 1/2
- Syphilis (Primary or secondary)
- Primary HIV infection
- Lymphogranuloma venereum
- Mpox
Non-sexually transmitted causes of genital ulceration
- Varicella zoster
- Fixed drug eruption
- Crohn’s disease
- Dermatoses
- Behcet’s disease
- Trauma
- Lipschutz ulcers (Ulcers secondary to any viral infection)
- Idiopathic
What are the 3 types of genital wart management
Topical
Ablative
Surgical
What are the topical managements of genital warts
Podophylotoxin
Imiquimod
Cataphen
What are the ablative managements of genital warts
Liquid nitrogen
Trichloroacetic acid
What are the surgical managements of genital warts
Electrocautery
Curettage
Debulking
Sexually transmitted or infective causes of genital lumps
- Genital warts (HPV)
- Molluscum contagiosum
- Mpox
- Scabies
Non-sexually transmitted causes of genital lumps
- Physiological
- Folliculitis
- Hydradenitis suppurativa
- Seborrhoeic keratoses
- Cancers
- Bartholin’s abscess
- Skin tags
- Lichen planus
- Pyoderma granuloma
What are some bacterial STIs
Gonorrhoea
Chlamydia
Mycoplasma
Ureaplasma
Syphilis
Causative organism of gonorrhoea
Neisseria gonorrhoea
Common ages of gonorrhoea infection
15-49
Transmission of gonorrhoea
Sexually transmitted
Microbiology of gonorrhoea
- Gram negative diplococci
- Screened by PCR
- Requires chocolate agar to grow
- Often overgrowth with normal flora
Presentation of gonorrhoea
Urethritis (Profuse yellow/green discharge)
Cervicitis
PID
Pharyngitis
Proctitis
Management of gonorrhoea
Ceftrioxone
Azithromycin
Causative organism in chlamydia
Chlamydia trachomatis
Most commonly affected by chlamydia
Women aged 15-24
Transmission of chalmydia
Sexually transmitted
Presentation of chlamydia
- Increased vaginal discharge
- Post-coital bleeding
- Dysuria
- Dyspareunia
- Rectal pain
- Urethritis
- Milky discharge
- Cervicitis
- Epididymo-orchitis
Complications of chlamydia
- PID
- Salpingitis
- Endometritis
- Tubal infertility
- Ectopic pregnancy
- Perihepatitis
- Reactive arthritis
- Fitz Hugh-Curtis syndrome
Testing for chlamydia
NAAT + Contact tracing
Management of chlamydia
- Doxycycline 100mg BD 1 week
- Azithromycin 1g stat → 500mg OD 2 days
- Ofloxacin
What is lymphogranuloma venereum
An infection caused by chlaymdia serovar L2
