Colorado tick fever (CTF) is an acute febrile illness caused by CTF virus, a double-stranded RNA virus in the Coltivirus genus of the family Reoviridae ( Box 215.1 ). , The virus is transmitted to humans through the bite of an infected Rocky Mountain wood tick, Dermacentor andersoni ( Fig. 215.1 ).

BOX 215.1
Colorado Tick Fever: Agent and Epidemiology

Agent

  • Colorado tick fever virus, Coltivirus genus, Reoviridae family

Vector

  • Dermacentor andersoni , Rocky Mountain wood tick

Natural Reservoir

  • Rodent, small mammal–tick cycle

Distribution

  • Western US and southwestern Canada at elevations from 4000 to 10,000 feet

Seasonality

  • March–September with an April–July peak

Risk Factors

  • Outdoor exposure in an endemic area

  • One transfusion-acquired case and 16 laboratory-associated cases reported

Fig. 215.1
Both adult male (A) and female (B) Dermacentor andersoni ticks can transmit Colorado tick fever virus.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here