Genital Tract Infections Flashcards
What type of epithelium is the vagina normally lined with?
Squamous epithelium
How is a vaginal epithelium and pH different in prepubertal girls and postmenopausal women?
The lack of oestrogen results in a thin, atrophic epithelium, a higher pH (6.5-7.5 vs <4.5pH) and reduced resistance to infection
What are some non-STI infections of the vulva and vagina?
Candidiasis (thrush); bacterial vaginosis; infection associated with foreign bodies
What causes candidiasis and what type of organism is it?
Candida albicans, a yeast-like fungus
What is the most common cause of vaginal infection?
Candidiasis
What are the risk factors for candidiasis?
Pregnancy, diabetes and the use of antibiotics
What are the symptoms (if any) of candidiasis?
‘Cottage cheese’ discharge with vulval irritation and itching. Superficial dyspareunia and dysuria may occur. The vagina and/or vulva are inflamed and red.
How do you investigate candidiasis?
A high vaginal swab is not routinely indicated if the clinical features are consistent with candidiasis
How do you treat candidiasis?
options include local or oral treatment
local treatments include clotrimazole pessary (e.g. clotrimazole 500mg PV stat)
oral treatments include itraconazole 200mg PO bd for 1 day or fluconazole 150mg PO stat
if pregnant then only local treatments (e.g. cream or pessaries) may be used - oral treatments are contraindicated
What is the pathology behind bacterial vaginosis?
It is when normal lactobacilli are overgrown and a mixed flora including anaerobes. Gardnerella vaginalis and Mycoplasma hominis.
What are the clinical features of bacterial vaginosis?
A grey-white discharge is present, but the vagina is not red or itchy. There is a characteristic ‘fishy’ odour from amines released by a bacterial proteolysis
How do you diagnose bacterial vaginosis?
Amsel’s criteria for diagnosis of BV - 3 of the following 4 points should be present:
- thin, white homogenous discharge
- clue cells on microscopy: stippled vaginal epithelial cells
- vaginal pH > 4.5
- positive whiff test (addition of potassium hydroxide results in fishy odour)
How do you treat bacterial vaginosis?
oral metronidazole for 5-7 days
70-80% initial cure rate
relapse rate > 50% within 3 months
the BNF suggests topical metronidazole or topical clindamycin as alternatives
What type of labour is BV linked to?
Preterm labour
What is the main cause of discharge in children?
Foreign body. Sexual abuse must also be considered but discharge is more often due to atrophic vaginitis due to low oestrogen levels
What is the organism responsible for toxic shock syndrome?
A toxin-producing staph aureus is responsible.
What are the clinical features of toxic shock syndrome?
Centers for Disease Control and Prevention diagnostic criteria:
-fever: temperature > 38.9ºC
-hypotension: systolic blood pressure < 90 mmHg
diffuse erythematous rash
-desquamation of rash, especially of the palms and soles
-involvement of three or more organ systems: e.g. gastrointestinal (diarrhoea and vomiting), mucous membrane erythema, renal failure, hepatitis, thrombocytopenia, CNS involvement (e.g. confusion)
How do you treat toxic shock syndrome?
Antibiotics and intensive care
What bacteria causes chlamydia?
Chlamydia trachomatis
What are the clinical features (if any) of chlamydia?
Urethritis and a vaginal discharge. The principal complication is pelvic infection, which may also be silent.
What syndrome can chlamydia cause?
Reiter’s syndrome
What are the clinical features of Reiter’s syndrome?
Urethritis, conjunctivitis an arthritis
How do you treat chlamydia?
Azithromycin
If pregnant then azithromycin, erythromycin or amoxicillin
What bacteria, and what type, causes gonorrhoea?
Neisseria gonorrhoea, a gram negative diplococci
What are the clinical features (if any) of gonorrhoea?
Vaginal discharge, urethritis, bartholinits, and cervicitis can occur and the pelvis is often infected. Men usually develop urethritis. Systemically, bacteraemia and acute septic arthritis
How do you diagnose gonorrhoea?
- nuclear acid amplification tests (NAATs) are now the investigation of choice
- urine (first void urine sample), vulvovaginal swab or cervical swab may be tested using the NAAT technique
- for women: the vulvovaginal swab is first-line
- for men: the urine test is first-line
- Chlamydia testing should be carried out two weeks after a possible exposure
How do you treat gonorrhoea?
IM ceftriaxone
What virus causes genital warts?
HPV 6 and 8
What are the clinical features of genital warts?
Appearances vary from tiny flat patches on the vulval skin to small papilliform (cauliflower-like) swellings. Warts are usually multiple and may affect the cervix
What cell change are genital warts linked to?
Certain oncogenic HPV types (mostly 16 and 18) and are associated with the development of cervical intraepithelial neoplasia
How do you treat genital warts?
1st line: Podophyllotoxin / imiquimod / sinecatechins
Cryotherapy or electrocautery is used for resistant warts