STIs Flashcards
What is Neisseria Gonorrhoeae resistant to?
Quinolones - ciprofloxacin
Beta lactams - penicillin binding
Macrolides
What are the principles for effective antimicrobial therapy?
Right drug - for patient and organism
Right dose - for patient (liver/kidney failure/child/elderly) and bacteria (minimum inhibitory concentration)
Right time - immediately
Right duration
What’re the principles of a microbiology diagnosis? How do you detect the pathogen and the response to the pathogen?
See it -> microscopy
Grow it -> culture
Kill it -> sensitivity
Detect pathogen (proteins and nucleic acids) Detect response to pathogen using serology
What type of bacteria is gonorrhoea?
Gram negative diplococci (often intracellular)
What’s the key technique used to diagnose chlamydia and gonorrhoea?
NAAT - nucleic acid amplification test
What are the pros and cons of using microscopy, culture and serology to diagnose gonorrhoea?
Rapid result in clinic
Less sensitive than NAAT
Requires skilled technician
Useful for individual treatment
What’s special about chlamydia? (cells where it’s found)
Found in columnar epithelium eg should always swab pharynx too (it’s an obligate intracellular bacterium)
What investigations are used for a syphilis diagnosis?
Microscopy: specific but low sensitivity and requires skilled technician and good sample
Culture not possible
Nucleic acid detection - PCR
Serology antibody detection - most commonly used and shows active syphilis
What drug is used for the prophylaxis of HIV?
PrEP (once a day)
How can STIs be transmitted?
Through sexual contact: oral, vaginal, anal, sex toys, douching
Skin/skin contact with some eg HSV, HPV
Non-sexual contact: syphilis can be passed in utero, most can be passed peripartum
Blood borne exposure
What are two bacteria that can cause urethritis?
Chlamydia trachomatis
Neisseria gonorrhoeae
What are causes of genital ulcers? STI and non-STI
STI: herpes simplex virus (HSV1 and HSV2) and syphilis
Non-STI: Crohn’s, allergy, trauma,
What’s epididymo-occhitis and it’s causes?
Red swollen epidydymis and testes
UTI - E.Coli
STI - gonorrhoea, chlamydia
What’s SARA?
Systemically acquired reactive arthritis
What’s the most likely diagnosis of a painless genital ulcer?
Syphyllis
