Bug Parade: Vector-Borne diseases

mosquitos

transmit Plasmodium between humans

tularemia

caused by Francisella tularensis

rodents and rabbits

Francisella tularensis reservoir

direct skin contact

inhalation of aerosols

tick or deerfly bites

tularemia transmission

ulceroglandular (45-80%)

oculoglandular

oropharyngeal

pneumonic

typhoidal

(presents similar to anthrax)

tularemia disease/symptoms

Blood culture

Others dependent on symptoms

Serology

tularemia specimen

Gram-negative coccobacillus

Stain poorly

Slow growth on chocolate

No growth on MacConkey or blood

Oxidase-negative

B-lactamase-positive

Francisella tularensis growth

Francisella tularensis

organism that causes tularemia

"tularemia belt": Kansas, Missouri, Oklahoma, Arkansas

tularemia geographical prevalence

Rickettsia rickettsii

organism that causes RMSF

Multiple Dermacentor (dog tick)

Rickettsia rickettsii reservoir

tick bite

RMSF transmission

Big three: fever, rash, worst headache ever

About 7 days after bite

RMSF symptoms

Closer to Appalachia, not Rocky's

RMSF geographical prevalence

Serology early in disease

PCR of lesions

RMSF specimen

do NOT culture (BSL-3)

Rickettsia rickettsii growth

Ehrlichia chaffeensis

organism that causes monocytic ehrlichiosis

Monocytic Ehrlichiosis

Monocytic Ehrlichiosis transmission

Missouri

Monocytic Ehrlichiosis geographical prevalence

Anaplasma phagocytophilum

Organism that causes Granulocytic Ehrlichiosis

Ixodes scapularis bite

“Blacklegged (Deer) Tick”

Granulocytic Ehrlichiosis geographical transmission

East Coast, Minnesota, Wisconsin

Granulocytic Ehrlichiosis geographical prevalence

deer and mice

Ehrlichiosis (Ehrlichia chaffeensis or Anaplasma phagocytophilum) reservoir

Headache, myalgia, fever, chills, rash in children

Thrombocytopenia, leukopenia, increased liver enzymes, late-stage CNS, respiratory failure, uncontrolled bleeding

Ehrlichiosis symptoms/disease

peripheral blood; CSF for PCR or serum

Ehrlichiosis specimen

Morula uncommonly observed

Use serology or PCR

Ehrlichiosis (Ehrlichia chaffeensis or Anaplasma phagocytophilum) growth

Borrelia burgdorferi

organism that causes Lyme disease

BSK medium

Incubate 32°C microaerophilic

Reliance on serology

Borrelia burgdorferi growth

deer and mice

Borrelia burgdorferi reservoir

Tick bite

(Ixodes scapularis)

Blacklegged (Deer) Tick

Lyme disease transmission

Multi-stage:

Early: erythema migrans (bullseye rash)

Disseminated: CNS, heart, and joints

Persistent: arthritis (chronic)

Lyme disease symptoms

East Coast. Minnesota, Wisconsin

Lyme disease geographical prevalence

Serology

Joint material

Urine

Lyme disease specimen

Treponema pallidum

organism that causes syphilis

humans

Treponema pallidum reservoir

Cannot grow in lab

Non-treponemal testing: Ab to lesion (titer rises and falls)

Treponemal testing: Ab to bug (titer always high)

Treponema pallidum growth

sex

syphilis transmission

Primary: chancre

Secondary: lesions on soles or palms

Tertiary: gumma, neurosyphilis, cardiosyphilic

syphilis symptoms/disease

Warmer weather (southern states: CA to FL)

syphilis geographical prevalence

serology, CSF

syphilis specimen

rocky mountain spotted fever

caused by Rickettsia rickettsii

monocytic Ehrlichiosis

caused by Ehrlichia chaffeensis

granulocytic Ehrlichiosis

caused by Anaplasma phagocytophilum

Lyme disease

caused by Borrelia burgdorferi

Syphilis

caused by Treponema pallidum

blacklegged (dear) tick

tick that causes granulocytic ehrlichiosis and lyme disease

dog tick

tick that causes RMSF

lone star tick

tick that causes tularemia and monocytic ehrlichiosis