Colorado Tick Fever –

Colorado Tick Fever


Colorado Tick Fever

Colorado tick fever is an acute, self-limited febrile sickness attributable to an infection with a Coltivirus.

Epidemiology & Demographics

  • •Incidence: Roughly 330 instances reported per yr within the U.S.
  • •Demographics: Youngsters and adults of each genders.
  • •Geography: Rocky Mountains at elevations of 4000 to 10,000 ft. Sporadic instances have been reported from areas of California outdoors the vary of Dermacentor andersoni.

Bodily Findings & Medical Presentation

  • •Incubation: 3 to 4 days is common however will be as much as 14 days.
  • •First signs: Fever, chills, extreme headache, extreme myalgias, and hyperesthetic pores and skin.
  • •Preliminary indicators and signs:
    • 1.Tick chew (reported by greater than 90% of oldsters)
    • 2.Fever and chills
    • 3.Headache
    • 4.Myalgias
    • 5.Weak spot
    • 6.Prostration and indifference
    • 7.Injected conjunctivae
    • 8.Erythematous pharyngitis
    • 9.Lymphadenopathy and hepatosplenomegaly could also be present in some sufferers
    • 10.Maculopapular or petechial rash 5.6% to 12% of instances
  • •These first signs final for 1 wk or much less, however 50% of sufferers have a febrile relapse 2 to three days after an preliminary remission. Weak spot and fatigue could persist for a number of months after the acute section(s). This power section is extra doubtless in older sufferers.
  • •In youngsters, 5% to 10% of instances are sophisticated by aseptic meningitis. In adults, uncommon issues embrace pneumonia, hepatitis, myocarditis, and epididymo-orchitis. Vertically transmitted fetal an infection is feasible.


  • •Infectious agent: Coltiviruses; seven species, together with three within the U.S.
  • •Vector: Wooden tick, D. andersoni
  • •Pathogenesis: Human transmission happens by tick chew. Tick season spans from March to September. The virus infects marrow erythrocytic precursors, explaining the protracted illness course as a result of viremia lasts for the life span of the contaminated pink blood cell.


Individuals develop into contaminated with Colorado tick fever (CTF) virus from the chew of an contaminated Rocky Mountain wooden tick (Dermacentor andersoni).

Rocky mountain wooden ticks are discovered within the western United States and western Canada at 4,000–10,000 ft above sea degree.

Ticks develop into contaminated with CTF virus once they feed on the blood of a reservoir animal (an animal that has the virus circulating in its bloodstream).

A very powerful reservoirs for CTF virus are small rodents resembling squirrels, chipmunks, and mice.

After the tick turns into contaminated, it passes the virus to different hosts (animal or human) whereas it feeds.

The virus isn’t transmitted from individual to individual, besides in uncommon situations by blood transfusion.

Since CTF virus can stay in pink blood cells for a number of months, blood and bone marrow shouldn’t be donated for six months following an infection.

Differential Analysis

  • •Rocky Mountain noticed fever
  • •Influenza
  • •Leptospirosis
  • •Infectious mononucleosis
  • •CMV an infection
  • •Pneumonia
  • •Hepatitis
  • •Meningitis
  • •Endocarditis
  • •Scarlet fever
  • •Measles
  • •Rubella
  • •Typhus
  • •Lyme illness
  • •Immune thrombocytopenic purpura (ITP)
  • •Thrombotic thrombocytopenic purpura (TTP)
  • •Kawasaki illness
  • •Poisonous shock syndrome
  • •Vasculitis


Contemplate Colorado tick fever within the presence of the above signs related to journey to an endemic space coupled with a historical past of tick publicity.

Laboratory Assessments

  • •Full blood depend:
    • 1.Leukopenia
    • 2.Atypical lymphocytes
    • 3.Average thrombocytopenia
  • •Virus identification in pink blood cells by oblique immunofluorescence
  • •Serology with enzyme-linked immunosorbent assay, neutralization, or complement fixation


  • •No particular remedy, though Coltiviruses are delicate to ribavirin.
  • •Mattress relaxation, fluids, acetaminophen
  • •Keep away from aspirin due to thrombocytopenia
  • •Prevention: Tick avoidance measures


No CTF virus vaccines are at present out there to be used in folks. Within the absence of a vaccine, prevention of CTF will depend on private protecting measures to lower publicity to contaminated ticks.

This contains avoiding wooded and bushy areas with excessive grass, utilizing repellents to discourage tick attachment, and discovering and eradicating ticks earlier than they’ve an opportunity to connect.

CTF virus will be transmitted via blood transfusions and bone marrow transplants. Individuals with confirmed CTF virus infections mustn’t donate blood or bone marrow for six months after their sickness.

CTF virus infections temporally related to blood transfusion or bone marrow transplant ought to be reported promptly to the suitable state well being division.

Search Extra Data

Extra details about lowering publicity to ticks is obtainable on the CDC Ticks web site.