Spirochetes

Question 1

properties of Spirochetes

Answer 1

• spiral shaped bacteria with axial filaments

Question 2

what types of bacteria are spirochetes?

Answer 2

• Borrelia (big size)
  
  • “Borrelia is Big”
• Leptospira
• Treponema
  
  • ​”BLT”

Question 3

how can Borrelia be visualized?

Answer 3

• using aniline dyes (Wright or Giemsa stain) in light microscopy due to size

Question 4

how can Treponema be visualized?

Answer 4

• by dark field microscopy or direct fluorescent antibody (DFA) microscopy

Question 5

Leptospira interrogans–where is it found?

Answer 5

• in water contaminated with animal urine

Question 6

what does Leptospira interrogans cause?

Answer 6

• leptospirosis
• Weil disease

Question 7

Leptospirosis

Answer 7

• caused by Leptospira interrogans
• symptoms:
  
  • flu like symptoms
  • myalgias (classically of calves)
  • jaundice
  • photophobia with conjunctival suffusion–erythema without exudate
• prevalent among surfers and in tropics (ie. Hawaii)

Question 8

Weil disease

Answer 8

• caused by Leptospira interrogans
• icterohemorrhagic leptospirosis
• symptoms:
  
  • severe form with jaundice and azotemia from liver and kidney dysfunction
  • fever
  • hemorrhage
  • anemia

Question 9

what is the cause of Lyme disease, and what is the method of transmission?

Answer 9

• Borrelia burgdorferi
  
  • transmitted by the Ixodes deer tick (also a vector for Anaplasma spp. and protozoa Bahesia)

Question 10

what is the natural reservoir for the Ixodes deer tick, and why?

Answer 10

• mouse
  
  • b/c mice are important to tick life cycle

Question 11

where is lyme disease common?

Answer 11

• northeastern United States

Question 12

what are the 3 stages of Lyme disease?

Answer 12

• Stage 1
  
  • early localized
    
    • erythema migrans (see pic)
    • flu like symptoms
• Stage 2
  
  • early disseminated:
    
    • secondary lesions
    • carditis
    • AV block
    • facial nerve (Bell) palsy
    • migratory myalgias/transient arthritis
• Stage 3
  
  • late disseminated
    
    • encephalopathies
    • chronic arthritis
• “A key Lyme pie to the FACE:
  
  • Facial nerve palsy (typically bilateral)
  • Arthritis
  • Cardiac block
  • Erythema migrans”

Question 13

Syphilis

Answer 13

• caused by spirochete Treponema pallisum

Question 14

primary syphilis

Answer 14

• localized disease presenting with painless chancre

Question 15

how to visualize primary syphilis?

Answer 15

• if available, use dark field microscopy to visualize treponemes in fluid from chancre
• VDRL + in ~80%

Question 16

secondary syphilis

Answer 16

• disseminated disease with constitutional symptoms
  
  • maculopapular rash
    
    • including on palms and soles
  • condylomata lata–see pic
    
    • smooth, moist, painless, wart like white lesions on genitals
  • lymphadenopathy
  • patchy hair loss
• Secondary syphilis–Systemic
• latent syphilis (+ serology without symptoms) may follow

Question 17

secondary syphilis–serologic testing and how to confirm diagnosis?

Answer 17

• serologic testing: VDRL/RPR (nonspecific)
• confirm diagnosis with specific test (ie. FTA-ABS)
• also confirmable with dark field microscopy

Question 18

tertiary syphilis

Answer 18

• gummas–see pic–chronic granulomas
• aortitis–vasa vasorum destruction
• neurosyphilis–tabes dorsalis
  
  • “general paresis”
• Argyll Robertson pupil–constricts with accomodation, but is not reactive to light
  
  • also called “Prostitute’s pupil” since it accomodates but does not react

Question 19

tertiary syphilis–signs

Answer 19

• broad based ataxia
• • Romberg
• Charcot joint
• stroke without hypertension

Question 20

how to test for neurosyphilis?

Answer 20

• test spinal fluid with BDRL, FTA-ABS, and PCR

Question 21

congenital syphilis

Answer 21

• presents with facial abnormalities such as:
  
  • rhagades–linear scars at angle of mouth (see pic)
  • snuffles–nasal discharge
  • saddle nose
  • notched (hutchinson) teeth
  • mulberry molars
  • short maxilla
• saber shins
• CN VIII deafness

Question 22

how to prevent congenital syphilis?

Answer 22

• treat mother early in pregnanct
  
  • placental transmission typically occurs after first trimester

Question 23

VDRL false positives

Answer 23

• VDRL detects nonspecific antibody that reacts with beef cardiolipin
• inexpensive, widely available test for syphilis, quantitative, sensitive but not specific
• false positive results on VDRL with:
  
  • Viral infection–ie. EBV, hepatitis
  • Drugs
  • Rheumatic fever
  • Lupus and leprosy

Question 24

Jarisch Herxheimer reaction

Answer 24

• flu like syndrome (fever, chills, headache, myalgia) after antibiotics are started
• due to killed bacteria (usually spirochetes) releasing toxins