5-67
Subjective: Symptoms
Sudden fever, headache, vomiting, and dizziness; rapid progression of mental status changes--disorientation,
focal neurologic signs, seizures, stupor and coma; followed usually by recovery, or death (1-60% mortality)
or severe sequelae.
Focused History: Have you completed the full vaccination series for JE? (significantly decreased risk of
JE) Was fever your first symptom? (typically, see sudden rise of fever after a period of apparent recovery
from acute febrile illness, or without any prodromal symptoms) Have you traveled outside the country or been
bitten by mosquitoes recently? If so, where? (look for opportunity for infection in endemic area within past
several weeks) Have there been recent outbreaks of animal diseases in the area? (look for epidemics of
equine encephalitis [VEE, EEE, and WEE], pig abortions [JE] and bird deaths [WN, SLE])
Objective: Signs
Using Basic Tools: Neurological: Use Glasgow coma scale (GCS) to track progression of mental status
changes, and gauge need for medical evacuation or consultation. (See Appendicies: GCS)
Vitals: Fever and respiratory insufficiency.
Inspection: Transient weakness, diminished sensorium, hyperactive deep tendon reflexes, sensory distur-
bances; limb paralysis (JE, TBE), paresis of the shoulder girdle or arms (TBE); tremors, abnormal move-
ments, and cranial nerve abnormalities (gaze paralysis, speech disorders) (JE).
Palpation: Nuchal (neck) rigidity may be present
Using Advanced Tools: Definitive diagnosis may require lumbar puncture, CT, EEG and other advanced
testing.
Assessment:
Differential Diagnosis
Herpes simplex encephalitis - focal, non-motor changes (personality, speech, temporal seizures)
Other Herpesviruses or HIV - see ID: Infectious Mononucleosis and HIV sections
Rabies, TB, meningitis- see appropriate sections
Subdural hematoma and other trauma - see Closed Head Injury on CD-ROM
Plan:
Treatment
There is no drug treatment for JE or other arboviruses. Closely monitor obtunded patients (seizures,
aspiration, etc.) pending evacuation.
Patient Education
General: Arboviruses are not directly transmitted from person to person
Activity: Bedrest.
Diet: As tolerated.
Medications: Analgesics for fever or pain (see Procedure: Pain Assessment and Control).
Prevention and Hygiene: Vaccinate personnel against JE. Decrease exposure to mosquito vectors (see
Preventive Medicine chapter).
Follow-up Actions
Return Evaluation: Decreasing Glasgow coma scale score, or onset of seizures or focal neurologic symp-
toms indicate disease progression and requirement for emergent evaluation. Onset of coma or respiratory
failure necessitates intensive care for airway management and possible assisted ventilation.
Evacuation/Consultation criteria: Evacuate suspected cases of arboviral encephalitis early and urgently.
Consult infectious disease specialists whenever this diagnosis is suspected.