Tick Borne Diseases

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Tick Borne Diseases

• Humbert Zappia
• Public Health Entomologist
• WV Department of Health Human Resources

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Tick Borne Diseases

• Rocky Mountain Spotted Fever (Rickettsia
  rickettsii)
• Human Ehrlichiosis (Ehrlichia spp.)
• Lyme Disease (Borrelia burgdorferii)
• Southern Tick-Associated Rash Illness
  (spirochetes)
• Babesiosis (Babesia spp.)
• Tularemia (Francisella tularensis)

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Rocky Mountain Spotted Fever

• American Dog Tick (Demacentor variabilis) is
  vector and reservoir in WV

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Rocky Mountain Spotted Fever cont.

• Incubation 5-10 days
• Initial symptoms non-specific
• High fever
• Severe headache
• Muscle pain

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Rocky Mountain Spotted Fever cont.

• Later signs symptoms
• Maculopapular rash on extremities (often palms
  and feet)
• Abdominal pain
• Joint pain
• Diarrhea

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Rocky Mountain Spotted Fever cont.

• Diagnosis
• Combination
• Clinical signs and symptoms
• Specialized confirmatory lab testing
• i.e. PCR

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Rocky Mountain Spotted Fever cont.
Number of Cases per Year
Average
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Rocky Mountain Spotted Fever cont.

• Case fatality rate 13 15 without treatment
• Best treated using a tetracycline antibiotic
• Acquired immunity
• Exposure thought to give long-term immunity,
  however, personal protection is recommended

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Ehrlichiosis

• Vectors
• Lone Star Tick (Amblyomma americanum)
• Human monocytic (HME)
• Deer tick (Ixodes scapularis)
• Human granulocytic (HGE)
• Reservoir
• White-tailed Deer (commonly)

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Lone Star Tick Range
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Lone Star Tick Proposed life cycle
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Deer Tick 2 year life cycle

• Fall and winter adult tick feeds and mates on
  white-tailed deer
• Spring fall off, eggs laid and hatch into larvae
• Summer larvae feed on small rodents and become
  infected
• After feeding larvae molt into nymphs which are
  dormant during the winter
• Second spring/summer nymphs actively feed on
  small and large animals
• Second fall nymphs become adults

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Ehrlichiosis cont.

• Incubation period 5-10 days
• Often mild or no symptoms
• When symptoms present
• Nonspecific
• Fever
• Headache
• Muscle aches
• Sometimes rash

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Ehrlichiosis cont.

• Other symptoms include
• Nausea
• Vomiting
• Diarrhea
• Cough
• Joint pain
• Confusion

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Ehrlichiosis cont.

• Diagnosis
• Combination
• Clinical signs and symptoms
• Specialized confirmatory lab testing
• i.e. PCR
• Can be fatal without treatment
• Best treated using a tetracycline antibiotic
• Acquired immunity
• Uncertain, personal protection is recommended

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Lyme disease

• Vector
• Ixodes scapularis (Eastern US)
• Reservoir
• wild rodents Peromyscus spp.
• Lyme disease can account for as much as 95 of
  all reported vector-borne illness in the U.S

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Infectious agent
Reservoir
Borrelia burgdorferi
Deer Mouse
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Ixodes sp. life stages
Adult female
Adult male
Nymph
Larvae
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Lyme disease cont.

• Incubation period days to weeks
• Symptoms
• Rash (erythema migrans) can be presented in 7 to
  14 days (80 of patients)
• Later symptoms
• General tiredness
• Fever
• Headache
• Stiff neck
• Muscle aches
• Joint pain

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Lyme disease cont.

• Diagnosis
• Clinical (rash) OR
• At least one late manifestation and laboratory
  confirmed
• i.e. A two-test approach using a sensitive enzyme
  immunoassay or immunofluorescence antibody
  followed by Western blot is recommended

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Lyme disease cont.

• Untreated (weeks or months later)
• Arthritis can develop
• Intermittent episodes of swelling and pain in
  large joints
• Neurological abnormalities
• Aseptic meningitis
• Facial palsy
• Motor and sensory nerve inflammation
• Encephalitis
• Cardiac problems (rarely)

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Lyme disease cont.

• Best treated using
• Doxycycline or amoxicillin (early disease)
• IV in later manifestations
• Acquired immunity
• None

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Average
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STARI Southern Tick-Associated Rash Illness

• Vector Lone Star Tick (Amblyomma americanum)
• Similar to Lyme Disease
• Unable to culture the spirochete

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Babesiosis

• Deer Tick (Ixodes scapularis) vector
• Hemoprotozoan
• Similar to malaria
• Complex life cycle

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Babesiosis cont.Life Cycle

• During a blood meal, infected tick introduces
  sporozoites into mouse host
• Sporozoites enter erythrocytes and undergo
  asexual reproduction, some differentiate gametes
• The definitive host (I. scapularis) ingests
  gametes, they unite and sporozoites result
• During a subsequent blood meal, sporozoites are
  introduced to human hosts

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Babesiosis cont.Life Cycle

• Sporozoites enter erythrocytes asexually
  reproduce 
• Multiplication of the blood stage parasites is
  responsible for the clinical manifestations of
  the disease. 
• Humans are dead-end hosts, however, human to
  human transmission is well recognized to occur
  through blood transfusions .

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Babesiosis cont.
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Tularemia

• Dermacentor (Dog) and Amblyomma (Lone Star)
  species vectors
• Multiple forms of infection
• Local
• Systemic (most lethal)
• Treatment with antibiotics

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Prevention of tick borne disease

• Personal protective measures
• Prompt careful inspection of your body and
  removal of ticks after visiting tick infested
  areas
• It may take 24-48 hrs of attachment before
  transmission of disease
• Wear light colored clothing
• Tuck pants legs into your socks
• Apply repellants
• DEET
• Permethrin

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Tick Removal

• Use fined tipped tweezers
• Grasp tick as close to skin
• surface as possible
• Pull steadily upward
• Do not twist
• Do not jerk
• If mouthparts remain, remove with tweezers
• If infection occurs see healthcare
• provider

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Tick Removal

• Do not squeeze, crush, or puncture tick
• Do not handle tick with bare hands
• (especially when removing them
• from domestic animals)
• Disinfect site after removal of tick
• and wash hands
• You may save the tick for identification, in case
  you become ill within several weeks

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Contact Information

• Greg Chrislip
• Public Health Entomologist
• Phone [phone]
• Email gregchrislip_at_wvdhhr.org
• Humbert Zappia
• Public Health Entomologist
• Phone [phone]
• District phone [phone]
• Email humbertzappia_at_wvdhhr.org