Virus: Omsk hemorrhagic fever virus, a flavivirus
Transmission: tick bite (Dermacenter reticulates) or contact with the muskrat (Ondatra zibethicus)
Clinical features:
(1) high fever
(2) headache
(3) nausea
(4) severe myalgias (muscle pain)
(5) cough
(6) hemorrhage
(7) behavioral or psychological difficulties
(8) decrease in hearing
(9) loss of taste
(10) skin rash with or without petechiae
(11) hyperemia of face and upper trunk
(12) injection of scleral blood vessels
(13) dehydration
(14) variable bronchitis and/or atypical pneumonia
(15) variable nephrosis
(16) variable meningitis and/or encephalitis
(17) variable myocarditis
(18) variable hypotension
(19) variable arthralgias
Laboratory features:
(1) elevated BUN and creatinine
(2) hypoproteinemia
(3) hemoconcentration initially followed by anemia
(4) thrombocytopenia
(5) albuminuria and/or hematuria
(6) left shift in the myeloid series with leukopenia or leukocytosis
(7) monocytosis
A patient may have:
(1) an asymptomatic infection
(2) a symptomatic infection lasting 1-2 weeks followed by recovery
(3) a biphasic infection with the initial phase followed a recurrence of signs and symptoms
