Colorado tick fever

Disease/Syndrome
Colorado tick fever
Category
Infection, Occupational
Acute/Chronic
Acute-Moderate (not life-threatening)
Synonyms
CTF; Bhanja tick-borne fever (Africa, Asia, & Europe); Thogoto tick-borne fever (Africa & Europe); Kemerovo tick-borne fever (Russia); [CCDM]
Biomedical References
Comments
INITIAL SYMPTOMS:
A flu-like syndrome; [CCDM] Pharyngitis and mild lymphadenopathy may occur. [PPID, p. 1161]

FINDINGS
Common symptoms of tick-borne viral diseases include headache, arthralgia, myalgia, and rash. Occasionally, patients with Colorado tick fever, Bhanja, or Thogoto have central nervous system infection. [CCDM, p. 29] Some patients have pharyngitis, vomiting, diarrhea, and/or spleen enlargement. About 5-12% of patients have a maculopapular or petechial rash. Approximately 10% of symptomatic children develop encephalitis or meningitis. Death, reported in children but not adults, was caused by hemorrhagic shock, DIC, or meningoencephalitis. The virus infects red blood cell precursors resulting in viremia for the life span of the RBCs (four months). In a persistent infection of the hematopoietic system, CTF may cause neutropenia, thrombocytopenia, and mild anemia. Older patients often have residual fatigue for weeks after resolution of the acute symptoms. [PPID, p. 1161; 1851-2] May be difficult to distinguish from Rocky Mountain spotted fever, but RMSF does not have biphasic fever pattern and is 20 times less common in western endemic areas. Also RMSF has typical rash, usually beginning on the 3rd to 5th day of the illness. [Cecil, p. 2156]

EPIDEMIOLOGY:
Reservoirs include ticks and small mammals. [CCDM, p. 30] A transfusion-related case has been reported. Laboratory transmitted cases have also been reported. [PPID, p. 1851]

For updated text and symptoms of infectious diseases, see iddx.com.
Latency/Incubation
3-4 days; [CCDM, p. 31]
Diagnostic
Viral culture; Serology: ELISA for detecting IgM and IgG and IFA for rapid detection of antibodies; RT-PCR: detect viral RNA; [PPID, p. 1852] Detect virions in erythrocytes by immunofluorescent antibody labeling. [Cecil, p. 2156]
ICD-9 Code
066.1
ICD-10 Code
A93.2

Symptoms/Findings, Job Tasks, and Agents Linked to This Disease

Job Tasks
Agents

Hazardous agents that cause the occupational disease: