Omsk Hemorrhagic Fever
Omsk hemorrhagic fever occurs in Siberia with related diseases possibly occurring in the Ukraine and North Rumania. It is caused by the OHF virus ( Flavivirus , group B) and is associated with the tick species Dermacentor pictus, D. marginatus , Ixodes persulcatus, I. apronophorus, and I. ricinus. The incubation period is 3–7 days. Frequently, there is atypical bronchopnemonia, hemorrhagic rash, and extensive internal hemorrhage. Mortality rates are 0.5–3 %.