STIs Flashcards
To be able to list common presentations, investigations and treatment options for common STIs in the UK
What causes bacterial vaginosis?
This is caused by an imbalance in the bacteria within the vagina (due to increased lactate production)
What signs can show bacterial vaginosis?
Positive KOH ‘whiff test’ - fishy odour on discharge Discharge may have bubbles, homogenous Increase in vaginal pH
What would a wet mount show?
Wet mount is when a sample of vaginal discharge is inspected under the microscope. There will likely be ‘CLUE CELLS’ - these are cells with a coccobaccilli coating (may make them look blurred) Lack of leucocytes - if there are some then think co-existent infection
Is bacterial vaginosis an STI?
no - so does not require treatment of partner
What can be complications of BV?
pelvic pain, upper reproductive organ inflammation, premature rupture of membranes, miscarriage, can increase risk of HIV
How is bacterial vaginosis treated?
Oral metronidazole for 7 days
What is the organism causing chlamydia? (give types)
chlamydia trachomatis (gram -ve)
A-C - affect eyes
D-K - affect genitals
L1-L3 = lymphgranuloma venereum (affects the lymph nodes)
What is the most common bacterial STI in the UK?
Chlamydia
How will chlamydia present?
70% of females and 50% of males are asymptomatic
Females: white mucopurulent cervicitis, intermenstrual/post-coital bleeding, dysparenuria (painful sex) and lower abdominal pain
Males: urethral discharge, urethritis, proctitis
What are complications of chlamydia?
PID - pelvic inflammatory disease
(if left untreated then a complication called Fitz-Hugh-Curtis syndrome can develop - this is when there is inflammation of the liver capsule and adhesions form)
Cervicitis, endometritis, saphlingitis Can cause tubal damage (leading to infertilify and ectopic pregnancy) Reactive arthritis Congenital (pass to baby during delivery - born with conjunctivitis)
How is chlamydia diagnosed?
HVS or VV swab (self-obtained) or first pass urine +/- rectal swab MUST BE DONE 14 DAYS AFTER POSSIBLE INOCULATION
How would lymphogranuloma venereum present?
PR bleeding, proctitis, abdominal pain, lymphadenopathy, rectal discharge
How is chlamydia treated?
Azithromycin (1g dose) OR Doxycycline for 7 days (100mg BD)
What is a fungal infection that can affect the genitals?
Candida infection (most commonly C.albicans)
How will C.albicans look on microscopy?
Will have budding fungal cells with hyphae extensions
How will candida infection present?
Present with increasing itch and change to discharge in females Males will have a spotty rash
How is candida diagnosed?
Mainly a clinical diagnosis but can also be swabbed if necessary
How is candida treated?
Clotrimazole cream or Fluconazole oral (look for AZOLE in the name and think fungal treatment)
What are some risk factors for developing candida infection?
Poorly controlled diabetes, immunocompromised patients, recent antibiotic therapy (allows for opportunistic infection) and high oestrogen levels (pill or pregnancy)
What organism causes gonorrhoea?
Neisseria gonorrhoea (gram negative diplococci)
How is gonorrhoea likely to be seen on gram film stain?
intracellularly as it is easily phagocytosed
What is the incubation period for Gonorrhoea?
2-5 days
How may someone present with gonorrhoea?
Females: pelvic pain, change to dicharge, dysuria
Males: purulent discharge and dysuria
What are coplications of gonorrhoea infection if untreated?
PID
tubal damage (infertility and ectopic)
miscarriage
passing to baby - conjunctivitis on delivery
proctitis
painful injection into testes
Where can both gonorrhoea and chlamydia infect?
Eyes, throat, rectum, urethra, endocervix
How do you treat gonorrhoea?
ceftriaxone (IM) and an antibiotic e.g. azithromicin (single dose no longer recommended)
(test of cure is recommended)
How is gonorrhoea diagnosed?
can be diagnosed via culture (endocervical swab or urethral swabs) - this will allow you to test against ABs to find appropriate treatment. Has 90% specificity for males but less for females (endocervical swab is also more invasive)
Can also be diagnosed via NAAT (urine or self-obtained vaginal swabs) - has higher sensitivity but cannot test against ABs
Describe the organism that causes syphilis
this is a spirochete shaped organism called Trepenoma Pallidum. It does not stain on gram stain so requires PCR, microscopy or serology for diagnosis.
It is transmitted through sexual contact, blood transfusion, trans-placental or can be contracted in health work
What are the stages of syphilis infection?
- Primary (chancre) - there will be a primary lesion at the site of infection called the chancre, may be asymptomatic
- Secondary - this occurs a few weeks after initial infection and may have symptoms of generalised flu, lymphadenopathy, snail trail ulcers, patchy alopecia, condylomata lata (genital warts)
- Latent - infection lays dormant and can reactivate - may self-cure at this point
- Late - coplications in the nervous system e.g. meningitis, stroke or dementia
Which is the most infective stage of syphilis infection?
Secondary - lesions will be oozing with t.pallidum
How is diagnosis of syphilis made?
Dark ground microscopy - look for spirochetes
PCR
Specific and non-specific serological testing
Describe indications for specific and non-specific serological tests?
Specific - to confirm diagnosis (include TPPA and TPHA)
Non-specific - to assess response to treatment (RPR)
ELISA IgM and IgG for screening tests
How is Syphilis treated?
penicillin (need this for a long time so can get long acting injectable preparations but need to be cautious of resistance)