Syphilis and HIV Flashcards
What family is syphilis part of?
spirochaetaceae
What are the sub species of treponema pallidum that cause disease?
pallidum; endemicum; pertenue ; T.carateum
What disease does endemicum cause?
Bejel
What disease does pertenue cause?
Yaws
What disease does T.carateum cause?
pinta
What makes diagnosis between the subspecies of treponema pallidum difficult?
pallidum; endemicum; pertenue are all morphologically and serologically indistinguishable
Where is Bejel found?
hot and dry climates
Where is Yaws foudn?
hot wet countries
Where is Pinta found?
Central and South America
What is the shape of syphilis?
helically-shaped
What is found on the outer membrane of syphilis?
limited OM proteins and no LPS
How does syphilis move?
spins
When is the infectious capacity of syphilis lost after harvesting?
within 2 days
What makes research with syphilis difficult?
cannot be cultivated for sustained periods on artificial media; slow doubling time (30-33hours)
What is the metabolic capacity of syphilis?
glycolysis only- no TCA or electron transport
What makes syphilis such a fussy organism?
small genome; limited metabolic capacity; no oxidase/catalase; no heat shock proteins
What are the oxygen/temp requirements of syphilis?
micro-aerophilic; doesn’t do well above 37 degress
What are the modes of transmission of syphilis?
direct contact with infectious lesions; vertical transmsiion or during pregnancy
What is the transmission rate of syphilis?
1/3rd of sexual contacts of syphilis will develop the disease
What is the incidence rate of syphilis in Europe in 2016?
6.1/100,000
What is the european syphilis gender ratio?
8:1
How many cases of syphilis were in HIV postiive individuals?
27% but HIV status unknown in 20%
Why are rates of syphilis increasing?
reduced condom use- HIV treatable; Prep; more risky sexual practicies
What drugs make up prep?
tenofovir/emtricitabine
What is the efficacy of prep?
86%
What is the effect of HIV on syphilis?
T.pallidum load is higher in patients with HIV
What is the ID50 for treponema pallidum?
57
What age is there a peak in MSM syphilis cases?
35-39 peak
Why is there a spike in syphilis cases in heterosexual females at 25-29?
first pregnancy syphilis testing
What is the time after contact with pallidum for primary disease?
9-90days
What is the time after pallidum contact for secondary disease?
6 weeks-6 months
How many chancres are found in the genitals?
90%
What can be a feature of secondary syphilis in the mouth?
snail-track ulcers
Aside from the classical whole body rash in secondary syphilis what other skin manifestation is seen?
condylomata in warm moist areas
What are the neurological complications of secondary syphilis?
acute meningitis and CN palsy
What can be seen in the eyes with secondary syphilis?
anterior, posterior involvement; keratouveitis
How long after initial innoculation does CVS syphilis happen?
15-30 years
What is seen with CVS syphilis?
affects any blood vessel, usually the ascending aorta- aneurysm. get associatied aortic regurgitation
When does gummatous syphilis occur after initial innoculation?
1-46years
What organs does gummatous syphilis commonly affect?
skin and bone
Waht are the 2 categories of neurosyphilis?
meningo-vascular and parenchymal
What are the symptoms of meningovascular syphilis?
HA; optic neuritis; tinnitus- infectious arteritis may result in stroke
What are the 2 main forms of parenchymal neurosyphilis?
general paresis; tabes dorsalis
What structure is affected in general paresis?
cortical white matter loss
What are the symptoms of general paresis?
cognitive function; personality- dementia like; hemiparesis
What are the symtpoms of tabes dorsalis?
lightening pains; patchy sensory lsoss; pupil changes(Argyll-Robertson); sensory ataxia; neuropathic ulcers and joints
What is the difference between early and late congenital syphilis?
early is within 2 years of life; late is presenting after 2 years
What are the features of early CS?
rash; haemorrhagic rhinitis; lymphadenopathy; hepatosplenomegaly; skeletal abnormalities
What are hte features of late CS?
interstitial keratitis; Clutton’s joints; hutchison’s incisors; high palatal arch; SN deafness; frontal bossing; saddlenose deformity; neuro involvement
What is the difference in primary syphilis presentation in HIV?
more likely to present with >1 chancer and may have larger and deeper lesions
How many HIV infected patients present with concomitant lesiosn of primary and secondary syphilis at diagnosis?
25%
How does HIV change the incidence of neurosyphilis?
increases incidence generally; and neuro complications (eye and ear; and meningitis) during early syphilis
What Cd4 and RPR titre is associated with a risk of neurosyphilis?
RPR >=1:32 and CD4<350
Why are CSF results hard to diagnose in HIV patietns?
HIV causes a CSF pleocytosis and raised protein
What is the effect of HIV on ocular invovlement of syphilis?
more severe uveitis in pateitn with HIV- panuveitis more common than isolate anterior uveitis; worse papillitis; optic neuritis and retrobulbar optic neuritis
What are the methods of direct detection of T.pallidum?
dark ground microscopy and PCR
What is the beneffit of PCR over dark ground microscopy?
higher sensitivty and specificity; can be used for both gential and oral lesiosn
What are the specific trepnoemal tests
?
EIA (treponemal enzyme immunoassay); TPPA (T.pallidum particle agglutination assay); TPHA (T.pallidum haemoagglutination assay); FTA-abs (fluoresent treponemal antibody absorption test) ; T. pallidum immunoblot
What are hte non-specififc serological tests for syphilis?
VDRL (venereal diseases research lab test) and RPR (rapid plasma reagin test)
What is the primary screening test for syphilis?
EIA- if primary suspected do IgM
What is the confirmatory test for syphilis?
different treponemal test; TPPA
What test should be done if positive test isn’t confirmed by standard confirmatory test?
immunoblot
What is RPR/VDRL used for?
to stage the infection and monitor treatment
What are the routine screening recommendatiosn for HIV positive patients?
at least annually; in outbreaks 6 monthly and high risk MSM screened every 3 months for STIs
What is the prozone phenomenon?
high antibody titres interferes with formation of antigen-antibody lattice network necessary to visualise a positive test
Why is direct groun microscopy; PCR and tissue biopsy important in HIV patients?
increased rate of negative serological test s
What is serofasting?
non treponemal antibodies persist for a long period of time rather than become completely non reactive with time
How much should RPR drop by 3 months after treatment?
2-fold
How long should patients be advised to refrain from sexual contact after syphilis treatment?
until lesions fully healed and 2 weeks following treatment completion
What is the JArish-Herxheimer reaction?
as bacteria die they release toxin and pt gets fever and flu symtpoms
What is the origin of macrolide resistnace in syphilis?
single mutant strain introduced into a specific sexual network and becomes endemic– simialr types in populations /geographical regions
