Chapter 13 - Omsk Hemorrhagic Fever Virus

Abstract

Omsk hemorrhagic fever virus (OHFV) causes severe, acute hemorrhagic fever in the northern lake-steppe, forest-steppe, and marsh regions of Western Siberia. Many OHFV infections are mild, so infection may be underreported. More serious symptoms of OHFV disease include dehydration, headache, nausea, severe pain in calf muscles and regional joints, along with cardiovascular, pulmonary, and renal symptoms. Most people completely recover after a long convalescent period. OHFV’s primary vectors are Dermacentor reticulatus and Dermacentor marginatus ticks whose primary vertebrate hosts are water voles and muskrats. An OHFV-associated disease was first reported in 1941. An outbreak in 1946–1958 affected over 1000 people. It reemerged in 1988 after the importation of 4000 North American muskrats. In addition to tick bites, OHFV is transmitted from contacting muskrat hides or bodily fluids and from drinking raw goat or sheep milk. Vaccines developed against tickborne encephalitis virus protect 100% of mice against virulent OHFV.