STI Flashcards
What are some common presentations of STI
discharges from mouth or genital, genital lesions, warts
What is the typical presentation of Neisseria gonorrhoea in men?
urethral discharge, pain due to clogged up urethra
What are some presentation of Neisseria gonorrhoea with oral sex
pharyngitis, lymphadenopathy
T/F Neisseria gonorrhoea is a gram +ve rod
False, it is gram -ve cocci
What is the target adhesion site of Neisseria gonorrhoea
the columnar epithelial cells in urethra or cervix
Why is Neisseria gonorrhoea infection more common in younger women?
Older women have squamous lining on cervix, offering more protection
What does the histology of Neisseria gonorrhoea swab look like?
packed with neutrophils with phagocytosed diplococci
What is the typical presentation of Neisseria gonorrhoea in female?
asymptomatic
What is the reason for the increasing resistance of Neisseria gonorrhoea
exchange of genetic material with Neisseria in mouth during oral sex
What is Fitz-Hugh-Curtis Syndrome?
A disseminated symptom of gonorrhoea, which involves bacteria ascending up the fallopian tube to infect around the liver
T/F Gonorrhoea is the most common STI
False, it is second to Chlamydia
What is the presentation of pelvic inflammatory disease?
tubal scarring + increased risk of infertility, fever, pelvic tenderness, discharge
T/F Babies are subjected to gonorrhoea infection if the mum is infected
True, they are exposed during delivery, typically presents with purulent/scarring/perforation of cornea and blindness
Why must we diagnose babies with gonorrhoea before any treatment?
We treat gonorrhoea with IV Cefotaxime, but if it’s other bacterial infection, we can just use topical antibiotic
What is a better way to diagnose gonorrhoea (better than swab)
First void specimen
What must we do when we culture Neisseria gonorrhoea
Use selective agar to inhibit normal flora to avoid lost of pathogen in the background
T/F PCR of STI diagnosis routinely combines gonorrhoea and Chlamydia
True. It’s not as specific for gonorrhoea as there may be cross reaction with Neisseria spp.
What is the treatment of gonorrhoea
Ceftriaxone (cephelosporin), working on cell wall
Azithromycin, working on 50s ribosome
T/F vaccine is available for Neisseria gonorrhoea
False
Which part of the Chlamydia cycle is infectious
Elementary bodies, which live outside the cells. Chlamydia is an obligate intracellular organism
What is serovar (of Chlamydia)
they are serological variants, a way to characterise Chlamydia infections
What does the elementary body turn into once it infects a cell?
reticulate body, which replicates and rupture into large numbers
What is the presentation of Chlamydia in men
dysuria, meatal erythema (redness at tip of penis), clear urethral discharge, testicular pain, prostatitis
What is the difference between discharge from Chlamydia and gonorrhoea?
Chlamydia - clear
Gonorrhoea - thick and obvious
Chlamydia is usually asymptomatic in women, but what are the possible symptoms?
cervicitis
endometriosis
vaginal discharge, dysuria, pelvic pain if bacteria ascends
Describe the process of Chlamydia Lymphogranuloma venereum (LGV)
Chlamydia can spread to local lymph nodes in a few weeks to cause a lot of suppuration. If not drained, they can cause fistula
What are the possible symptoms of a baby infected with Chlamydia during delivery
conjunctivitis within 2 weeks
delayed pneumonia with staccato cough
Why do we do follow up tests with patients treated for Chlamydia
there is a chance of reinfection or there may be a lack of response to initial treatment
What are the options of treatment Chlamydia
Azithromycin or Doxycycline
Avoid doxycycline for pregnant women
T/F Trochomonas vaginalis is a gram +ve bacteria
False, it’s a parasite with interesting mobility
What is the quality of discharge from infection of Trochomonas vaginalis
frothy, green-yellow, more alkaline
Aside from discharge, what are some other presentations of Trochomonas vaginalis
strawberry cervix due to erythema, friable mucus
Is fixed gram stain a good technique for Trochomonas imaging?
No, wet-prep is better for observing its motility. Fix-stained Trochomonas just looks like neutrophil
What are the options of treatment for Trochomonas vaginalis
Metronidazole or Tinidazole
What is the presentation of primary syphilis
painless chancre
What is the presentation of secondary syphilis?
systemic rash, lymphadenopathy, abdo pain from hepatitis
T/F Early latent syphilis describes latency within 1 year
True, while late latent indicates 2 years after infection
T/F You are much more infectious in early latent stage of syphilis
True, and it’s also more likely to be asymptomatic
Why is late latent syphilis harder to treat?
the organism has lower metabolic demand at this stage
What is the presentation of tertiary syphilis?
gumma in joints and root of aorta, neurosyphilis which can lead to mental illness
T/F Microscopy is a good technique to diagnose syphilis
False, Treponema pallidum doesn’t gram stain well
What is the treatment of syphilis?
Single dose of penicillin for primary and secondary infection. 3 weeks of weekly injection for late latent
How does Mycoplasma genitalium present?
urethritis in men, cervicitis in women
acute endometriosis, PID
How do we diagnose M. genitalium?
electron microscopy or NAAT (PCR, but not widely available)
What is the treatment of M. genitalium
Azithromycin, but if fail, use Moxifloxacin
