SPIROCHETES

Question 1

Spirochetes are what type of pathogen?

Answer 1

Spiral shaped bacteria

Question 2

What are different strains of the Spirochetes?

Answer 2

-T.pallidum (Syphilis)
-Rickettsia rickettsii (Rocky Mountain Spotted Fever)
-Borrelia burgdorferi (Lyme disease)

Question 3

What is the vector for Rickettskia rickettsii (Rocky Mountain Spotted Fever)?

Answer 3

-Tick borne (DOG TICK)
*Common in Southeastern U.S.

Question 4

What is the pathogenesis of Rocky Mountain Spotted Fever?

Answer 4

Tick must be attached to host for 6-10 hours
-Rickettsia is released from the tick’s salivary glands and move into endothelial cells that line blood vessels
-Will cause increased vascular permeability
-Edema and thrombi can form and may cause vessel occlusion

Question 5

How does Rocky Mountain Spotted Fever present?

Answer 5

HALLMARK SIGN: petechial rash beginning on wrists, ankles, palms, and soles

Unexplained febrile illness: fever, chills, myalgia, headache, nausea, vomiting

Commonly presents in the Spring/Fall when exposed to ticks in South East America (endemic area)

Complications which can occur: encephalitis, ARDS, bleeding disorder

Question 6

How can Rocky Mountain Spotted Fever be diagnosed?

Answer 6

-WBC with leukopenia and thrombocytopenia (low platelets)
-Hemocrat and Hemoglobin (H&H) can show anemia
-Blood cultures to isolate bacteria
-Lumbar puncture/spinal tap for abnormal brain findings

Question 7

How can Rocky Mountain Spotted Fever be treated?

Answer 7

Treat within 5 days
-Doxycycline (even in children)

IF PREGNANT: Chloramphenicol

Prevention: avoid ticks!

Question 8

What is the vector for Borrelia burgdorfi (Lyme Disease)?

Answer 8

-Ticks (RODENT AND DEER TICKS)
-Common in the North East U.S. (in Summer months)

MOST COMMON TICK BORNE DISEASE IN U.S. AND EUROPE

Question 9

What is the primary reservoir for Borriela burgdorfi (Lyme Disease)?

Answer 9

Rodents and deer (tick bites them to contract bacteria)

Question 10

How does Lyme Disease present?

Answer 10

-Early localized ERYTHEMA MIGRANS BULLS EYE RASH (in 80% of patients)
-Non-specific viral like symptoms within 30 days

Early disseminated (spread): multiple erythema migrans lesions, neuro and cardio involvement (weeks to months after)
-NEURO TRIAD: Meningitis, cranial neuropathy (CN7), radiculoneuropathy (damage to nerve roots/bilateral nerve palsy)
-ocular manifestations possible

Late Lyme: persistent arthritis, encephalopathy, polyneuropathy (malfunction of peripheral nerves) with partial paralysis (months to years after)

Question 11

How is Lyme Disease diagnosed?

Answer 11

Clinical (evaluation, history)

Disseminated/Late diagnosis: serology, PCR, CSF test if neuro

Question 12

How is Lyme Disease treated?

Answer 12

-Doxycycline
-Amoxicillin in kids
IF PREGNANT: Ceftriaxone or Cephalosporin

Prophylactic (preventative) treatment: if had a tick, but no symptoms give a one time dose of Doxycycline

Prevention! avoid ticks

Question 13

How is Syphilis (T. pallidum) transmitted?

Answer 13

-Sexual contact with lesions
-Mother to fetus
-Lesions coming into contact with broken skin
-Blood transfusions (less common)

Question 14

What is the pathogenesis of Syphilis? What is its incubation time?

Answer 14

Penetrates the skin and enters the blood/lymphatics
-Causes systemic infection
-CNS invaded in early infection
-30% of patients will have abnormal findings by secondary stage of disease

Incubation time: average 3 weeks

Question 15

What is the primary phase of Syphilis infection?

Answer 15

Primary phase: Painless chancre lesion at transmission site after 3-6 weeks (punched out base with rolled edges), spirochete isolation here will heal in 3-12 weeks

Question 16

What is the secondary phase of Syphilis infection?

Answer 16

Secondary phase: malaise, fever, myalgia, lymph nodes, rash, mucocutaneous lesions all over the body (palms, soles, and oral), gray/white lesions in moist areas (condylomata lata), alopecia

Question 17

What is the tertiary phase of Syphilis infection?

Answer 17

Tertiary phase: Neuro gummatous (inflammatory neuro tissue damage, ulcerations, and necrosis developeved over years)

**Happens 10 years after

Question 18

What is the latent phase of Syphilis infection?

Answer 18

Recurrence of skin lesions, if untreated can develop into tertiary syphilis

Question 19

What is the congenital Syphilis?

Answer 19

Mother with syphilis can pass it to the fetus causing spontaneous abortion

-if fetus survives: widespread condylomata lata rash (gray/white lesions), rhinitis

May cause: SADDLE NOSE, SABER SHINS, HUTCHINSON’S TEETH, DEAFNESS, BLINDNESS

Question 20

How can Syphilis be diagnosed?

Answer 20

-Serology (blood) VDRL, RPR, IgG tests

-Dark field microscopy spirochetes under microscope

Question 21

What are some complications which may arise from late stage syphilis?

Answer 21

-Meningitis (with damage to the brain)
-Tabes dorsalis (damage to nerves that carry info to brain)
-Dorsal root disruption
-General paresis
-Argyll-Robertson pupil: pupils do not constrict in bright light

Question 22

How can early stage syphilis be treated?

Answer 22

-Benzathine Penicillin
-If allergic: Doxycycline

Question 23

How can Neuro/ocular Syphilis symptoms be treated?

Answer 23

Penicillin G (IV) for 10-14 days

Question 24

How can latent Syphilis be treated?

Answer 24

-Benzathine Penicillin 2.4 million units Intramuscular injection weekly for 3 weeks

Question 25

What is the Jarisch-Herxheimer reaction from Syphilis?

Answer 25

An acute febrile response from treatment/lysis of spirochetes, it usually resolves within 24 hours