Tick-Borne and Zoonotic Diseases in the United States David Spach, MD Professor, Division of Infectious Diseases University of Washington, Seattle

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• Tick-Borne and Zoonotic Diseases in the United
  StatesDavid Spach, MDProfessor, Division of
  Infectious DiseasesUniversity of Washington,
  Seattle

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• North American Ticks

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Tick Quiz
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From Spach DH et al. N Engl J Med
1993329936-47.
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Important North American Ticks
Ixodes Female (Adult)
Ixodes Male (Adult)
Ixodes Nymph
Amblyomma Female (Adult)
Dermacentor Female (Adult)
Ornithodoros (Adult)
From Spach DH et al. N Engl J Med
1993329936-47.
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Ixodes scapularis Ticks
Adult Female
Adult Male
Nymph
Larva
Centimeter Scale
From CDC Lyme Disease Home Page.
www.cdc.gov/ncidod/dvbid/lyme/
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Ixodes Nymph Tick
From Spach DH et al. Washington State Lyme
Disease Monograph.
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Ixodes Adult Females Unfed and Fed
From Spach DH et al. Washington State Lyme
Disease Monograph.
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Case History Question

• A 17-year-old girl presented to the emergency
  room with lower extremity weakness. She had
  prolonged recent outdoor exposure. Her weakness
  was symmetrical and had begun about 8 hours prior
  to coming to the ER sensation is intact. A tick
  is found embedded in her scalp. The most
  appropriate course of action is1. Give IV
  ceftriaxone x 14 days2. Remove tick and observe
  closely3. Give IM streptomycin x 10 days4.
  Arrange for emergent plasmapharesis

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Tick ParalysisClinical Features

• Early Features- Paresthesias- Leg weakness-
  Absence of fever
• Later Findings- Ascending paralysis- Ataxia-
  Hyporeflexia/Areflexia
• Late Findings- Bulbar signs- Hypoventilation

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• How should you remove at tick?

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Tick Removal

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Case History

• A 48-year-old woman presents with myalgias and a
  painful skin rash on her leg. She recently
  returned from a one week vacation in eastern
  Washington and says the rash began one day after
  she was bitten by something on her leg. The most
  appropriate course of action is1. No
  antibiotics required2. Give PO Doxycycline for
  14 days3. Give IV Ceftriaxone for 14 days4.
  Give IV Ampicillin and Gentamicin x 10 days

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Case History
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Tegenaria agrestis (Hobo Spider)
Male
Female
From http//hobospider.org
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Recluse Spiders (Loxosceles sp) Distribution in US
From Vetter RS.
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Diff Dx of Skin Lesions
From Young DM, et al. Arch Surg 2004139951-3.
From CDC Prevention
From Lowy FD. N Eng J Med 1998339520-32.
From CDC Prevention
From Darwin Vest
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Case History

• A 28-year-old man presented to clinic with a 16
  cm erythematous, annular skin lesion on his right
  flank and flu-like symptoms. He spent the past
  30 days hiking in the mountains. The most
  appropriate course of action is1. Give PO
  Doxycycline for 14 days2. Reassure and dont
  give antibiotics3. Draw serology (Lyme) and
  treat if positive4. Give IV Ceftriaxone for 14
  days

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Erythema Migrans Rash
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Erythema Migrans Rash
From Steere AC. N Engl J Med 2001345115-25.
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Lyme Disease Erythema MigransTreatment

• Preferred- Doxycycline 100 mg PO bid x 14
  days- Amoxicillin 500 mg PO tid x 14 days-
  Cefuroxime 500 mg PO bid x 14 days
• Alternative - Azithromycin 500 mg PO qd x 7-10
  days - Clarithromycin 500 mg bid x 14-21 days

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Case History

• A 43-year-old man from Westchester county, NY
  presents with fever and erythema migrans 7 days
  after a tick bite. He is started on
  amoxicillin, but 4 days later returns with
  headache, fever, and myalgias. Labs show
  leukopenia, thrombocytopenia, and increased
  hepatic aminotransferase levels. The most
  appropriate course of action is1. Give high
  dose corticosteroids2. Give PO Doxycycline3.
  Give IV Ceftriaxone4. Give IV Gentamicin

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Ehrlichiosis Anaplasmosis in United States
E. chaffeensis A.
phagocytophilium E. ewingii
Amblyomma
Ixodes
Amblyomma
Monocytes
Granulocytes
Granulocytes/Eos
HME
HGA
HGE
From CDC Ehrlichiosis Home Page.
www.cdc.gov/ncidod/dvrd/ehrlichia/Index.htm
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Ehrlichiosis Anaplasmosis

• Human Monocytic Ehrlichiosis- Organism
  Ehrlichia chaffeensis- Transmission Amblyomma
  ticks- Cells Monocytes/Macophages
• Human Granulocytic Anaplasmosis- Organism
  Anaplasma phagocytophilium- Transmission Ixodes
  ticks- Cells Granulocytes

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Ehrlichiosis Laboratory Studies
Liver Function Tests
Platelet Count

From Fishbein DB et al. Ann Intern Med
1994120736-43.
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Ehrlichiosis AnaplasmosisTreatment

• First Line- Doxycycline 100 mg PO bid x 10 days
• Second Line (Doxycycline allergy, Pregnancy)-
  Rifampin 300 mg bid x 10d

Since rifampin does not treat Lyme disease,
patients should also receive amoxicillin or
cefuroxime

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Case History

• A 67-year-old man from Wisconsin develops fever,
  severe malaise, and dark urine while visiting in
  Seattle. Two weeks prior he went on a 7-day
  hunting trip in rural Wisconsin. Labs show HCT
  31 platelet count 49,000. Optimal therapy
  would consist of1. Ceftriaxone x 10 days2.
  Penicillin x 10 days3. Quinine Clindamycin x
  7 days4. Streptomycin x 7 days

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Babesiosis Treatment

• First Line Azithromycin 500-1000 mg PO day 1,
  then 250 mg PO qd x 6-9d plusAtovaquone 750
  mg PO bid x 7-10d ORClindamycin 300-600 mg
  IV q6h (600 mg PO q8h) x 7-10 d plusQuinine
  650 mg of salt PO q8h x 7-10d

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Case History

• A 71-year-old geologist presents with a 3-day
  history of fever, chills, and myalgias. Seven
  days prior he was in rural eastern Washington and
  slept in an old cabin. Labs show hematocrit
  42, platelet count 67,000, and an abnormal blood
  smear. The most likely diagnosis is1.
  Relapsing fever2. Lyme disease3.
  Leptospirosis4. Colorado tick fever

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From Spach DH et al. N Engl J Med
1993329936-47.
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Relapsing FeverTreatment

• First Line- Doxycycline 100 mg PO bid x 7-10
  days-

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Tick-Borne Relapsing Fever in NorthwestNumber of
Relapses
From Dworkin MS et al. Clin Infect Dis
199826122-31.
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Case History

• A 29-year-old woman is admitted with suspected
  RMSF. Which laboratory study is NOT often
  observed with RMSF1. WBC gt 12, 0002. Platelet
  count lt 150,0003. Hyponatremia4. Increased CSF
  WBC count

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RMSF in US 1981-1992 Average Incidence by County

From Thorner AR et al. Clin Infect Dis
1998271353-9.
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RMSF Clinical Manifestations
From Catherine Wilfert (Duke University Medical
Center)
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RMSF Treatment

• First Line- Doxycycline 100 mg PO bid x 7-10
  days
• Second Line- Chloramphenicol
• Promising
• - Fluoroquinolones

From CDC RMSF Home Pagewww.cdc.gov/ncidod/dvrd/rm
sf
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• Rabies

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Case History Question
Silver-Haired Bat

• A 29-year-old male is bitten on the shoulder by
  a bat and the bat escaped. What percent of
  Rabies Immune Globulin should be given at the
  wound site?1. 252. 503. 754. 100

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Rabies Postexposure ProphylaxisRabies Immune
Globulin

• Administer 20 IU/kg body weight.  If
  anatomically feasible, the full dose should be
  infiltrated around the wound(s) and any remaining
  volume should be administered IM at an anatomical
  site distant from vaccine administration.  MMWR
  199948 (RR-1) 275-9.

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Rabies Post-Exposure Prophylaxis
Previously Vaccinated
Not Previously Vaccinated

• Wound cleansing
• No RIG
• Vaccine day 0 and 3

• Wound cleansing
• RIG
• Vaccine day 0,3,7,14,28

Administer vaccine as IM in deltoidAdminister
full dose of RIG around wound if possible
remaining volume give at site distant from
vaccine site
From
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Rabies Post-Exposure Prophylaxis
Not Previously Vaccinated

• Wound cleansing
• Rabies Immune Globulin
• Rabies Vaccine day 0,3,7,14

Administer vaccine as IM in deltoidAdminister
full dose of RIG around wound if possible
remaining volume give at site distant from
vaccine site
Note Number of recommended doses of rabies
vaccine changed from 5 to 4 (ACIP June 24, 2009)
From CDC. MMWR 2008571-26.
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Case History Question

• In which of the following scenarios you
  administer rabies post-exposure
  prophylaxis 1. A 41-year-old woman is bitten
  by her neighbors dog 7 days ago while jogging by
  their house the dog is behaving normally2. A
  mother awakens and finds a bat in the room of her
  4-year-old child (and the bat escapes3. A
  22-year-old man picks up a dead bat in his yard
  (with bare hands) and throws it down into a large
  ravine4. A 48-year-old man tells you during a
  routine medical visit that he suffered a
  unprovoked dog bit in Thailand 3 months ago

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• Hantavirus Pulmonary Syndrome

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Case History Question

• A 49-year-old woman is admitted to the hospital
  with a suspected diagnosis of hantavirus
  pulmonary syndrome. Which of the following would
  be LEAST characteristic of the clinical
  presentation of hantavirus pulmonary syndrome?
• 1. CSF pleocytosis
• 2. Increased hematocrit
• 3. Increased white blood cell count with
  immature forms
• 4. Thrombocytopenia

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Hantavirus Pulmonary Syndrome Reservoir
Peromyscus maniculatusDeer Mouse
Source CDC and Prevention
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Hantavirus Pulmonary SyndromeThrough November
11, 2009
By State of Exposure
Source CDC and Prevention
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Hantavirus Pulmonary Syndrome Chest Radiograph
Early Stage
Severe
CDC
Later Stage
Interstitial
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Hantavirus Pulmonary SyndromeProgression of
Disease
Recovery
Prodrome
Cardiopulmonary

Death
Picture
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• Dog Cat Exposure

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Case History Animal Bite

• A 33-year-old woman living in Washington State is
  bitten on her hand by her cat while trying to
  break up a fight between her cat and dog. One
  day later her wound is red and painful and she
  comes to the ER for evaluation. Which ONE of the
  following is TRUE? 1. Her risk of getting
  rabies from this cat bite is about 22. Cat
  bites become infected more often than dog bites
  3. Bartonella is a likely cause of the
  infection4. Pseudomonas is a likely cause of the
  infection

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Microbiology of Infected Cat Bites
From Talan DA, et al. NEJM 199934085-92.
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Microbiology of Infected Dog Bites
From Talan DA, et al. NEJM 199934085-92.
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Dog Cat Bites Wound Infections Therapy

• Therapy (Oral) - Amoxicillin-CA (Augmentin) x
  7-14 days
• Therapy (Intravenous - Ampicillin-sulbactam
  (Unasyn) - Ertapenem (Invanz)
• Therapy (Penicillin-Allergic) - Clindamycin plus
  Fluroquinolone

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Bartonella henselae Soft Tissue Infection
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Cat Scratch Disease Azithromycin Therapy
From Bass JW et al. Pediatr Infect Dis
199817447-52.
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Cat Scratch Disease Neuroretinitis Macular Star
Left Fundus. Eight days later, the infiltrate of
the optic nerve is less discrete. Exudates in a
star pattern are clearly evident around the fovea.

From Bhatti MT et al. Arch Neurol 2001581008-9.
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Case History Skin Soft Tissue

• This 36-year-old man is admitted to intensive
  care unit 3 days after suffering a dog bite on
  his right knee. He has a BP 85/60, he has
  diffuse purpura, and lab studies that show
  evidence of DIC. Tragically, he died 6 hours
  after admission to the ICU. Which organism
  likely caused this infection? 1. Moraxella
  catarrhalis2. Pasteurella canis3.
  Capnocytophaga canimorus (DF-2)4. Pseudomonas
  aeruginosa

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• Questions?

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