NAME: Colorado tick fever virus
SYNONYM OR CROSS REFERENCE: Tick-borne fever, arbovirus
CHARACTERISTICS: Coltivirus (Reoviridae), 65-70 nm diameter, ds RNA (Note change from single to double strand RNA)
PATHOGENICITY: Acute febrile, often diphasic, dengue-like disease with infrequent rash; headache, chills, muscle pain, photophobia; brief remission followed by second bout of fever lasting 2-3 days; neutropenia, thrombocytopenia; occasional encephalitis, myocarditis, or hemorrhagic symptoms (especially in children); deaths are rare
EPIDEMIOLOGY: Western North America; most frequent in adult males, but also affects children and women; seasonal incidence parallels the period of greatest tick activity; endemic in occurrence and common in affected area
HOST RANGE: Humans, small mammals
INFECTIOUS DOSE: Unknown
MODE OF TRANSMISSION: By bite of an infective tick; immature ticks acquire infection by feeding on infected viremic animals; ticks remain infected through the various moults and transmit virus to humans by feeding as adult ticks
INCUBATION PERIOD: Usually 4-5 days
COMMUNICABILITY: Not directly transmitted from person to person, except by transfusion; ticks remain infective for life; virus is present in blood in humans during the course of fever, from 2-16 weeks or more after onset
RESERVOIR: Small mammals, ground squirrels, chipmunk, porcupine
ZOONOSIS: Yes, through bite of an infected tick
VECTORS: Tick - Dermacentor andersoni
DRUG SUSCEPTIBILITY: N/A
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite, 70% ethanol, glutaraldehyde, formaldehyde
PHYSICAL INACTIVATION: Inactivated by heat (50-60°C for at least 30 min)
SURVIVAL OUTSIDE HOST: Does not survive outside of host
SURVEILLANCE: Serological studies or isolation of virus from blood
FIRST AID/TREATMENT: No specific treatment
IMMUNIZATION: None available
PROPHYLAXIS: None available
LABORATORY-ACQUIRED INFECTIONS: 16 reported laboratory-acquired infections
SOURCES/SPECIMENS: Blood, CSF, other tissues; arthropods, depending on the stage of infection
PRIMARY HAZARDS: Accidental parenteral inoculation, contact of the virus with broken skin or mucous membranes, bites of infected laboratory rodents or arthropods; infectious aerosols may also be a potential source of infection
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, safety equipment and facilities are recommended for activities with potentially infectious clinical materials and arthropods and for manipulations of infected tissue cultures, embryonated eggs, and rodents
PROTECTIVE CLOTHING: Laboratory coat; gloves and gown when working with infectious materials
OTHER PRECAUTIONS: None
SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with paper towel and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time before clean up (30 min)
DISPOSAL: Decontaminate before disposal; steam sterilization, incineration
STORAGE: In sealed containers that are appropriately labelled
Date prepared: January 2000
Prepared by: Office of Laboratory Security, PHAC
Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Copyright ©
Health Canada, 2001