Syphilis Flashcards
How would you classify the bacterial morphology of treponema pallidum subspecies pallidum
gram negative spirochete bacteria
What is the name of the bacteria that causes syphilis
treponema pallidum subspecies pallidum
how can syphilis be transmitted
direct contact with an infected lesion i.e. sexual
vertical (most commonly transplacental spread in utero)
infected blood products
sharing of infected needles
what is the transmission rate of syphilis to sexual partners
up to a third of sexual partners will develop the infection
what stages of syphilis are more likely to cause in utero (transplacental) spread to the foetus?
early syphilis much more likely to transmit to baby in utero (i.e. primary or secondary syphilis, infection for < 2 years, when RPR > 8)
how do we define early and late syphilis
early < 2 years and late > 2 years
what are the three stages of syphilis and can you describe typical features
primary syphilis: incubation period 9-90 days (typically 21 days), primary papule (chancre) and regional lymphadenopathy
secondary syphilis: 4-10 weeks after initial chancre developed, multi-system involvement - maculopapular rash inv palms and soles classically, alopecia, oral snail track ulcers, condylomata lata (warty growths in warm, moist areas perianal common), generalised lymphadenopathy. can also cause hepatitis/splenomegaly, glomerulonephritis and 1-2% will develop meningitis presentation or cranial nerve involvement - neurological syphilis
tertiary syphilis: occurs years after 20-40 years after initial infection
1. Gummatous - skin lesions
2. cardiovascular - aortitis, aortic regurgitation
3. neurological involvement: general paresis (dementia) or dorsal column involvement or meningovascular syphilis
what proportion of patients if not treated at the stage of primary syphilis infection will go on to develop secondary syphilis
a) 10%
b) 20%
c) 25%
d) 50%
c) 25%
if secondary syphilis is not treated it will resolve and go into which phase of syphilis
asymptomatic latent phase (defined as early < 2 years or late > 2 years)
what proportion of patients with untreated syphilis go on to develop tertiary syphilis?
a) 1/4
b) 1/3
c) 1/2
d) 3/4
b) 1/3
how can neurosyphilis present in terms of secondary stage of disease
meningitis - neck pain, photophobia, headaches etc
cranial nerve palsies - often affecting optic nerve (CN II) and vestibulocochlear (CN VIII)
what are the signs of neurosyphilis in late tertiary syphilis
- general paresis - cognitive decline e.g. dementia
- Meningovascular - infective infarcts, vasculitis
- Tabes dorsalis - inflammation of dorsal column (loss of vibration sense, areflexia, loss of joint position) - argyll robertson pupil, sensory ataxia
what would you find on examination if argyll robertson pupil?
pupil does not constrict to light but constricts to accomodation
sign of tertiary neuro syphilis
How do we classify congenital syphilis
early (< 2 years old) and late > 2 years old
what are some of the signs of late congenital syphilis
hutchinson’s incisors (notched teeth)
mulberry molars
clutton’s joints (bilateral joint swelling classically knees)
sensineural deafness,
saddlenose deformity
frontal bossing
what are some of the signs of early congenital syphilis
bloody snuffles ( haemorrhagic rhinitis)
rash
generalised lymphadenopathy
hepatosplenomegaly
skeletal abnormalities
what tests can we do to identify t. pallidum direct from genital chancres
dark ground microscopy - identify the spirochete
PCR swab
what sites can you not perform dark ground microscopy on lesions when ? syphilis
not suitable for oral lesions due to commensals - but can do oral PCR in these situations
can you use a syphilis PCR swab on oral lesions
yes
how do we classify syphilis serological tests
specific to t. pallidum
non specific to t. pallidum
can syphilis antibody tests distinguish between syphilis and endemic treponemes
no all tests will be positive for treponemal pallidum (e.g. can’t distinguish pallidum subspecies between yaws/ pinta/ bejel)
can you name the specific antibody treponemal tests
EIA
CLIA
TPPA
TPHA - Treponema pallidum
t.pallidum EIA IgM
(most of these test IgG and IgM)
can you name the non-specific antibody treponemal tests
RPR
VDRL
these measure disease activity
what type of syphilis tests act as the screening test for syphilis
treponemal specific antibody tests (in sheff we use EIA IgG)e.g. CLIA, EIA or TPHA (no longer use TPPA)
ideally tests that combine IgG and IgM
what is the main issue with EIA IgM
only use in primary syphilis, limited by its suboptimal sensitivity
if you get a positive screening test what is the next step
confirm it with an secondary test ideally a different type of treponemal specific antibody test