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HPS: Pulse oximetry may demonstrate hypoxia even if CXR is normal in HPS. CXR may show bilateral
whiteout, pleural effusion, Kerley B lines, increased vascular markings; may see elevated white blood count,
thrombocytopenia, increased hematocrit (up to 55-65% in severe infection).
Assessment:
Differential Diagnosis
Leptospirosis - pulmonary hemorrhage presentation of leptospirosis (as seen in Hawaii) may present
similarly to HPS. Travel history, conjunctival redness and skin contact with standing fresh water all suggest
leptospirosis.
Hemorrhagic fever virus - more prominent bleeding (HFRS can have bleeding, but late in course) and rash
seen with some types.
Typhus - responds to doxycycline, presents with a rash, lowered white blood cell count, and tache noire for
some types. Also consider plague, tularemia.
Plan:
Treatment
Primary: Avoid excess fluids; consider blood transfusion and Trendelenburg position for shock; give O 2.
For HFRS, ribavirin IV 2 gram loading dose, then 1 gram q 6 hours for 4 days, then 500mg q 8 hours
for 6 days.
Patient Education
General: This infection has high mortality. Most deaths occur within the first 48 hrs.
Activity: Bedrest
Diet: As tolerated
Medications: In HFRS, once patient enters the polyuric phase (about day 8), replace urine losses carefully to
avoid dehydration (use careful output measurements).
Prevention and Hygiene: Minimize human-rodent contact. Protect food source, keep rodents out of sleeping
places, wet down deserted dwellings (preferably with detergent or disinfectant) to avoid aerosolization and
clean out before living there. Use gloves to handle dead rodents and their nests.
Follow-up Actions
Consultation Criteria: Monitor oxygenation with a pulse oximeter. Be prepared to intubate for respiratory
failure. Use fluids modestly in HPS to maintain cardiac output. Most deaths occur within the first 48 hours.
Evacuation: Patient needs to be transported to hospital where dialysis (HFRS) and ventilatory support (HPS)
are available. Avoid air transport once patient enters the capillary leak syndrome presentation of this illness.
Zoonotic Disease Considerations
Principal Animal Hosts: Rodents
Clinical Disease in Animals: Asymptomatic
Probable Mode of Transmission: Aerosols from rodent excretions and secretions
Known Distribution: Worldwide
ID: Yellow Fever
LTC Niranjan Kanesa-thasan, MC, USAIntroduction: The yellow fever virus causes hemorrhagic fever (severe illness with bleeding), and treatment
of these patients is challenging even in optimum environments. As with other viral hemorrhagic fevers