UGI 4 Flashcards
how is syphilis transmitted
direct contact with primary or secondary lesions
what stages is syphilis curable
this genital ulcerative disease is easily curable in the primary and secondary stages
what is seen in primary stage of syphilis
hard, painless but sensitive ulcers aka chancre 9-90 days post infection with syphilis
what happens if you treat or don’t treat syphilis in its primary stage
treat: disappears in a week
untreated: disappears in 4-12 weeks or could progress to secondary stage
definitive diagnosis of early syphilis and what test is not done and why?
definitive: darkfield microscopy
not done: serology because no antibodies in this stage
what is seen in secondary stage of syphilis
- generalized maculopapular rash
- symptoms indicative of systemic infection
- flulike syndrome
- condylomata lata
what is typically not seen in secondary stage of syphilis and if seen what should be considered
usually do not see chancre (painless ulcers) in secondary stage but if seen usually suggestive of an additional STI
what is condylomata lata
wet mucous patches that are contagious
where is the maculopapular rash of syphilis usually seen
palm, soles of feet, face
syphilis is common in what population
males - especially men who have sex with men
what is early latent and late latent phase of syphilis
it is a state after secondary but before tertiary where persons are not in diseased state
what is seen in tertiary phase of syphilis
comes 15-20 years post infection
- neurosyphilis (dementia, hallucinations, neurological symptom can happen in any stage but more common here
- cardiovascular effects
- gummatous: destroys viscera and mucocutaneous areas
how does congenital syphilis occur
treponema pallidum crosses uterine or placental membrane leading to systemic infection in developing fetus
what occurs as a result of treponema pallidum crossing the uterine or placental membrane
- most cases leads to spontaneous, septic abortion
- those that become live birth –> actively infected with syphilis
what is seen in late stage congenital syphilitic infection
- stromal haze due to interstitial keratitis
- saddle nose
- Hutchinson’s teeth
characteristics of treponema pallidum
- spirochete
- 3 flagella so motile
- replicates slowly so no in vitro culture
- obligate human pathogen
- unusual outer membrane so no LPS or porins
pathogenesis of treponema pallidum
- enters subepithelial tissues via skin breach: fastidious
- evasion of the immune system
- diffuse chronic inflammation and damage to CNS
what does it mean for treponema pallidum to be fastidious
it does not tolerate a wide range of environmental conditions
importance of hyaluronidase in syphilis
it facilitates perivascular infiltration aka it is the spreading factor
what protects treponema pallidum from phagocytosis
coating of fibronectin
why is there tissue damage and destruction in syphilis
patient’s immune response to the infection
specimen and definitive diagnosis for early syphilis
- specimen is exudate from skin lesion
- definite diagnosis is the darkfield microscopy
how do you detect the actual organism - the treponema pallidum
PCR
the difference between the two presumptive diagnostic tests of syphilis
- nontreponemal test: tests for diseased states so you can get both false negative and false positives –> just not specific enough
- treponemal test: used for monitoring treatment of syphilis
types of nontreponemal and treponemal test
- nontreponemal: VDRL (venereal disease research laboratory) and RPR
- treponemal: FTA-ABS (fluorescent treponemal antibody absorbed) and TP-PA (treponema pallidum passive particle agglutination) and EIAs
those who test positive for syphilis should also be tested for what and why?
HIV - increase chance of transmission because of the ulceration making infiltration easier
treatment in primary, secondary, early latent is possible. what tx should you use?
benzathine penicillin
pathogen in chancroid and where is this popular
obligate human pathogen hemophilus ducreyi
popular in Africa, Asia, and Latin America
clinical presentation of chancroid
- soft chancre or chancroid
- painful genital ulcer
- spontaneously rupturing buboes
characteristic of hemophilus ducreyi
- gram neg anaerobic rods called coccobacilli which just means it is pleomorphic
- fastidious
how do you view hemophilus ducreyi/diagnose it
use gram stain (gentian violet simple stain)
what does hemophilus ducreyi resist
phagocytosis
virulence factor of hemophilus ducreyi
- outer membrane serum resistance protein
- two toxin: hemolysin and CDT (cytolethal distending toxin) which causes tissue destruction
other than microscopy exam, what is another way of diagnosing chancroid
excluding treponema pallidum and HHV 1 and 2
difference between chancroid and syphilis
- chancre has soft chancre while syphilis has hard chancre
- chancroid is painful ulcers no matter what while syphilis is usually painless unless secondarily infected
- chancroid is diagnosed with gram stain while syphilis is diagnosed with darkfield
