5-95
ID: Ehrlichiosis
LTC Glenn Wortmann, MC, USAIntroduction: Ehrlichiosis is a tick-borne bacterial illness. Human infection with Ehrlichia has only recently
been appreciated, with the first case reported in 1987. Most disease occurs in the United States, although
it has been reported in Africa, Scandinavia and Western Europe. The severity of infection ranges from
subclinical to fatal.
Subjective: Symptoms
Headache, fever, rash, myalgias.
Focused History: Have you had a tick bite recently? (typical exposure) Do you have a headache and fever?
(suggests ehrlichiosis in late spring and early summer) How long have you felt sick? (often presents with the
abrupt onset of fever, headache and myalgias)
Objective: Signs
Using Basic Tools: Temperature over 101°F; rash in 30% (most commonly involving the trunk; not
associated with site of tick bite).
Assessment:
Differential Diagnosis: Many infections present similarly, but fever and headache (especially in a patient
with exposure to ticks) should prompt the consideration of ehrlichiosis. Rocky Mountain Spotted Fever and
meningitis have substantial clinical overlap.
NOTE: Serology testing of blood is available at many hospitals.
Plan:
Treatment:
Doxycycline 100 mg bid for x 7-10 days. Treatment often results in rapid clinical improvement and
defervescence within one to two days.
Patient Education:
General: Avoid tick exposure.
Activity: As tolerated.
Diet: As tolerated.
Medications: Doxycycline can cause photosensitivity, and should not be given to young children or
pregnant/ breastfeeding women.
Prevention and Hygiene: Avoid tick exposure.
No Improvement/Deterioration: Return for evaluation.
Follow-up Actions
Consultation Criteria: Failure to improve after initiation of antibiotics.
ID: Plague
COL Naomi Aronson, MC, USAIntroduction: Plague (Yersinia pestis), a highly fatal illness, is usually transmitted by a bite from a rodent flea
or by contact with infected wild rodents (rats, squirrels, chipmunks, prairie dogs), rabbits, or domestic cats.
Ingestion of infected animal tissues, direct handling, inoculation or inhalation of contaminated tissues are less
common causes. The current plague vaccine does not protect against pneumonic plague, which can spread