SPIROCHETES Flashcards
Spirochetes are what type of pathogen?
Spiral shaped bacteria
What are different strains of the Spirochetes?
-T.pallidum (Syphilis)
-Rickettsia rickettsii (Rocky Mountain Spotted Fever)
-Borrelia burgdorferi (Lyme disease)
What is the vector for Rickettskia rickettsii (Rocky Mountain Spotted Fever)?
-Tick borne (DOG TICK)
*Common in Southeastern U.S.
What is the pathogenesis of Rocky Mountain Spotted Fever?
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
How does Rocky Mountain Spotted Fever present?
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
How can Rocky Mountain Spotted Fever be diagnosed?
-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
How can Rocky Mountain Spotted Fever be treated?
Treat within 5 days
-Doxycycline (even in children)
IF PREGNANT: Chloramphenicol
Prevention: avoid ticks!
What is the vector for Borrelia burgdorfi (Lyme Disease)?
-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
What is the primary reservoir for Borriela burgdorfi (Lyme Disease)?
Rodents and deer (tick bites them to contract bacteria)
How does Lyme Disease present?
-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)
How is Lyme Disease diagnosed?
Clinical (evaluation, history)
Disseminated/Late diagnosis: serology, PCR, CSF test if neuro
How is Lyme Disease treated?
-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
How is Syphilis (T. pallidum) transmitted?
-Sexual contact with lesions
-Mother to fetus
-Lesions coming into contact with broken skin
-Blood transfusions (less common)
What is the pathogenesis of Syphilis? What is its incubation time?
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
What is the primary phase of Syphilis infection?
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
What is the secondary phase of Syphilis infection?
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
What is the tertiary phase of Syphilis infection?
Tertiary phase: Neuro gummatous (inflammatory neuro tissue damage, ulcerations, and necrosis developeved over years)
**Happens 10 years after
What is the latent phase of Syphilis infection?
Recurrence of skin lesions, if untreated can develop into tertiary syphilis
What is the congenital Syphilis?
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
How can Syphilis be diagnosed?
-Serology (blood) VDRL, RPR, IgG tests
-Dark field microscopy spirochetes under microscope
What are some complications which may arise from late stage syphilis?
-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
How can early stage syphilis be treated?
-Benzathine Penicillin
-If allergic: Doxycycline
How can Neuro/ocular Syphilis symptoms be treated?
Penicillin G (IV) for 10-14 days
How can latent Syphilis be treated?
-Benzathine Penicillin 2.4 million units Intramuscular injection weekly for 3 weeks
What is the Jarisch-Herxheimer reaction from Syphilis?
An acute febrile response from treatment/lysis of spirochetes, it usually resolves within 24 hours
