Syphilis Flashcards
What is the etiologic agent of syphilis?
A spirochete, Treponema pallidum
Can T. pallidum be grown in the lab?
No, but it can be propagated in rabbit testes
Does syphilis have distinct sequential phases?
Yes, including latent phases
Can T. pallidum cross the placenta?
Yes, resulting in congenital syphilis
What is the pathology of syphilis largely due to?
Host’s cellular inflammatory response, it resembles and AI response
What is the hallmark feature of primary syphilis?
Non-painful ulcer called a chancre, developing at site of entry of treponeme
Secondary syphilis is what kind of infection?
Systemic, characterized by fever, swollen LNs, mucous membrane lesions, and sometimes a skin rash that eventually includes soles and palms and/or wart-resembling lesions (condylomata kata)
What is Lab Dx of syphilis done by?
Serology, and by microscopic examination of scrapings
What are all forms of syphilis treated with?
Penicillins, most commonly Pen G; prevention with abstinence and use of condoms
What type of bacterium is T. Pallidum?
Helical/spiral-shaped bacterium
T. pallidum is very thin, what does this mean?
Too thin to be seen by standard direct light transmission microscopy (gram stain useless)
What method is T. pallidum seen by?
Indirect light microscopy method called darkfield microscopy
What is dark field useful for?
Useful Dx method early in disease process, before antibodies develo
What do spirochetes resemble?
gram negative bacteria
What membranes to spirochetes have?
An inner membrane, a periplasm with peptidoglycan and an outer sheath/membrane
What is different about the outer sheath in spirochetes?
It’s proteins are mainly lipoproteins and lipids (not LPS) that probably contribute to the pathogenic inflammatory process
What is the immune response to spirochetes?
Rigorous humoral and cellular response that does not eliminate the infection; Host’s cellular immune response probably controls the infection but also responsible for pathology (tert sylph)
Does T. pallidum have a latent phase?
Yes, unknown mechanism and if untreated infection and continue for life/can progress to tertiary stage
What is the incubation time and symptom resolution time of primary syphilis?
2-3 week incubation w/ resolution in 3-6 weeks
What is the manifestation and resolution time of 2ndary syphilis?
1-2 months after infection; resolve in a month or so w/o tx
What is early latent syphilis?
The 1-2 yr period after resolution of 2ndary syphilis
What is late latent syphilis?
Begins 1-2 years post infection, may last lifetime, may progress to tertiary or resolve spontaneously
What can be affected in tertiary syphilis?
Almost any organ system can be affected
Will symptoms be present at birth with congenital syphilis?
Sometimes, stigmata may develop 2 yrs or more after birth
What are the signs/sx of primary syphilis?
Painless ulcer (chancre) at sight of entry, nontender inguinal LAD
What are the signs/sx of secondary syphilis?
Disseminated infection, hyperpigmented maculopapular rash over entire body that with time extends to palms and soles; mucous membrane patches in mouth and genitals a.k.a. snail track lesionsl condylomata lata; and the patient is sick (fever, headache, diffuse LAD); may also have mild meningitis
What 4 diseases have a rash on palms and soles?
Secondary syphilis, RMSF, hand foot mouth dz, and rarely meningococcemia
What are the signs/sx of early latent Syphilis?
No symptoms, positive serology, may relapse to secondary (can spread in utero)
What are the signs/sx of late latent syphilis?
No symptoms, positive serology, no relapse to secondary (not infectious even to fetus)
What are the signs/sx of tertiary syphilis?
Progressive, inflammatory disease that may take years to develop; Tertiary S in endarteritis, few spirochetes can be detected in lesions, Gummas, CV and CNS S can take years to develop (Any organ system can be involved here… LOTS of symptoms)
What are the signs/sx of Congenital S?
May or may not be symptoms at birth, can cause spontaneous abortion; disseminated infection transmitted transplacentally after first trimester via blood, no chancre
In late congenital syphilis what develops?
Stigmata over years, generally starting around age 2
Syphilis is an STD, but how else can it be transmitted?
Biting or through a crack in skin by touching a chancre or snail track lesion or handling contaminated catheter (doesn’t remain viable outside the body very long)
How is lab diagnosis of syphilis done?
Serology and occasionally microscopic examination of scrapings from chancre
What types of serology are done for syphilis?
Non-treponemal serologic tests and treponemal tests
What are the non-treponemal serologic tests for syphilis?
Non-specific tests; the Ag is NOT T. pallidum but rather is beef heart mitochondria cardiolipin. KNOW THESE TWO NAMES: Rapid Plasma Reagin (RGR) test and Venereal disease research laboratory (VDRL); they are cheap and sensitive, there are false positives; Titers drop after patient is cured (good test for antibiotic efficacy)
What are the Treponemal tests?
Antigen is pathogenic T. Pallidum. KNOW THIS ONE: Fluorescent Treponemal Antigen-Absorbed (FTA-ABS); Titers tend to remain for months to years after patient is cured
What is in the Ddx for syphilis?
Any ulcer forming STD; herpes, LGV, haemophilis ducreyi, warts, etc.
How is syphilis prevented/treated?
Large, single IM dose of PenG
