Spirochetes

• syphilis is an

  infectious venereal disease cuased by sprochette Treponema pallidum
• syphillis transmission

  sexual contact w infected lesions*

  mother to fetus in utero

  blood

  breaks in skin in contact with infected lesions
• syphilis patho

  rapidly penetrates intact mucous membranes -> enter lymphatics -> systemic inf
• incubation time to primary chancre

  3 wks
• is CNS invaded in syphillis

  yes, early -> 30%+ pts have abnormal CSF findings
• untreated primary infection of syphillis leads to

  meningovascular neurosyphilis and ultimately parenchymatous neurosyphilis
• histo hallmark of syphillis

  endarteritis and plasma cell rich infiltrate (attacks RBC)
• syphillitic infiltrate consistent with

  delayed type hypersensitivity response to T pallidum
• tertiary syphillis response

  gummatous ulcerations and necrosis
• antigens of T pallidum induce

  host productuon of trepnonemal antibodies
• t/f immunity to syphhilis is incomplete

  true
• syphillis stages

  primary -> painless chancre at site of trasmission (flask shape)

  secondary -> 4-10 wks after, spread throughout body, systemic sxs, rash hands and feet, condylmoata lata, contagious

  tertiary -> yrs, slow inflammatory response
• t/f primary chancre heals with or without treatment

  true, resolve in 3-12 wks
• condylomata lata

  painless, highly infectious, grey-white lesions that develop in warm moist areas (secondary syph)
• Latent syph

  secondary syph resolved, but pts seropositive -> 1/3 go on to develop tertiary
• tertitary syph MC sequlae

  CV syph (80-85%)
• syphillitic meningitis

  w/in 6mo of primary inf

  • menigicovascular syph
  • tabes dorsalis -> wide based gait
  • dorsal root disruption -> loss of pain and temp sensation
  • general paresis with cortical damage to brain, mimics dementia
  • argyll-robertson pupil - pupil that does not react to light but constricts
• CV syph occurs at least ____ after primary inf

  10 years
• MC CV syph formation is

  aneurysm formation in the ascedning aorta
• Congenital syph

  causes high rate of spontanous abortion and still births

  by 2yo-> sxs similar to severe secondary syph and widespread condylomata lata and rash

  "snuffles"

  "saddle nose"

  "saber shins"

  "hutchinson teeth"
• syph dx

  serology -> VDRL, RPR, Treponema IgG (screen)

  dark field uncommon
• syph tx

  primary -> Benzathine pencillin 2.4 IM (thick suspension), doxy if allergic

  Latent -> Benzathine pencillin 2.4 IM, weekly x3

  Nuero/ocular syph -> Pen G IV 10-14 days
• Jarisch-Herxheimer rxn

  syph tx -> cause spirochete death -> release inflmmatory molecules -> trigger cytokine response

  starts few hours after initial tx for 24 hrs

  tx sxs
• RMSF caused by

  rickettsia rickettsia
• rickettsia rickettsia is

  MC rickettsial infection
• RMSF endemic to

  southeastern and south central US
• RMSF transmitted by

  dog tick
• tick season

  may-sept
• RMSF patho

  tick needs to be attached to host for 6-10 hrs to be infected
• R rickketsi has tropism for

  endothelial cells that line BV -> vascular permeability -> thrombi form
• RMSF commonly reffered to as

  " great imitator"
• hallmark of RMSF

  petechial rash beginning at palms and soles
• high suspicion for RMSF if

  • febrile
  • hx tick expo
  • travel to endemic area
  • seasonal

  considers if unexplained febrile and no hx of tick bite (70% of people dont know they have been bit)
• tick borne illness labs

  thrombocytopenia -> can lead to DIC

  increase LFTs

  decrease WBC
• RMSF dx

  serology

  blood culture (uncommon)

  lumbar puncture for concern for meningitisy
• RMSF tx

  1. doxy (even young kids)
  2. pregnant -> chloreamphenicol
• Lyme caused by

  borrelia burgdoferi
• lyme disease is

  MC tick borne disease in north america and europe
• lyme endemic

  northeast and upper midwest
• lyme reservoir

  rodents