|Description:||This transmission electron microscopic (TEM) image revealed some of the morphologic details displayed by the Colorado tick fever virus (CTFV), a member of the genus Coltivirus, one of nine genera of the virus family known as the Reoviridae. Coltivirus particles are ˜80 nm in diameter and have a core ˜50 nm in diameter. Electron microscopic studies have shown particles with a relatively smooth capsomeric surface structure, and icosahedral symmetry.|
Infection of humans with CTFV is characterized by abrupt onset of fever, chills, headache, retroorbital pain, photophobia, myalgia, abdominal pain, and generalized malaise. Diphasic or triphasic febrile patterns have been observed, usually lasting for 5 to 10 days. Severe forms of the disease that involve infection of the central nervous system (CNS) or hemorrhagic fever, pericarditis, myocarditis, and orchitis have been rarely observed, mainly in children. Severity is sufficient to result in hospitalization of ˜20% of patients.
The Colorado tick fever virus inhabits North America, and is found in the Rocky Mountain region of the United States and in Canada with a distribution closely matching that of its vector, the Rocky Mountain wood tick, Dermacentor andersoni.