STDs Flashcards
STDs and HIV
Having STDs, especially those with legions, increase the chance for getting an HIV
Syphilis
Caused by treponema pallidum. High risk in MSM, drug users. Caused by sexual transmission, can be spread through placenta.
Treponema virulence factors
Host cell fibronectin coats spirochetes to protect against phagocytosis.
Stages of syphilis
Primary, secondary, latent, late
Does T. pallidum grow in culture?
No, visualize on darkfield microscopy after scraping chancres, mucus patches, or condylomata lata
How to serologically test for T. pallidum?
RPR- uses cardiolipin Ag and charcoal to test for reagin Ab.
Prozone effect
Ab excess, from secondary syphilis, causes too much lattice formation. Can be seen in HIV positives.
Primary syphilis
Chancre, prototypical lesion. Painless, smooth ulcer with clean base. No exudates unless really severe. Painless lymphadenopathy. Heals on its own in 3-6 weeks.
What does treponema look like?
Spirochete.
How does 1 syphilis progress to secondary syphilis?
Spirochetes spread from chancre and enter the blood stream.
Cell type in chancre?
Plasma cell
Secondary syphilis
Florid stage, spirochetes are everywhere. Can have palm rash, sole rash.
Is syphilitic rash infectious?
No, unless there are mucous patches or chondylomata lata.
Latent syphilis
The period after infection when the patient is asymptomatic but has a reactive RSR.
When is an LP necessary?
HIV/AIDS with RPR>1:32 , anybody with neurologic changes. Treatment failure with IM PCN.
