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Test ID CAVPC California Virus (La Crosse) Encephalitis Antibody Panel, IgG and IgM, Spinal Fluid

Useful For

Aiding the diagnosis of California (La Crosse) encephalitis

Method Name

Immunofluorescence Assay (IFA)

Reporting Name

Calif(LaCrosse) Encep Ab Panel, CSF

Specimen Type

CSF


Specimen Required


Container/Tube: Sterile vial

Specimen Volume: 0.5 mL

Additional Information: This test is not offered for specimens originating in New York.


Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time
CSF Refrigerated (preferred) 14 days
  Frozen  14 days

Clinical Information

California (La Crosse) virus is a member of bunyaviridae and it is 1 of the arthropod-borne encephalitides. It is transmitted by various Aedes and Culex mosquitoes and is found in such intermediate hosts as the rabbit, squirrel, chipmunk, and field mouse.

 

California meningoencephalitis is usually mild and occurs in late summer. Ninety percent of infections are seen in children <15 years of age, usually from rural areas. The incubation period is estimated to be 7 days and acute illness lasts ≤10 days in most instances. Typically, the first symptoms are nonspecific, last 1 to 3 days, and are followed by the appearance of central nervous system signs and symptoms such as stiff neck, lethargy, and seizures, which usually abate within 1 week. Symptomatic infection is almost never recognized in those >18 years old. The most important sequelae of California virus encephalitis is epilepsy, which occurs in about 10% of children; almost always in patients who have had seizures during the acute illness. A few patients (estimated 2%) have persistent paresis. Learning disabilities or other objective cognitive deficits have been reported in a small proportion (<2%) of patients. Learning performance and behavior of most recovered patients are not distinguishable from comparison groups in these same areas.

 

Infections with arboviruses can occur at any age. The age distribution depends on the degree of exposure to the particular transmitting arthropod relating to age, sex, and occupational, vocational, and recreational habits of the individuals. Once humans have been infected, the severity of the host response may be influenced by age. Serious

California (La Crosse) virus infections primarily involve children, especially boys. Adult males exposed to California viruses have high prevalence rates of antibody but usually show no serious illness. Infection among males is primarily due to working conditions and sports activities taking place where the vector is present.

Reference Values

IgG: <1:10

IgM: <1:10

Reference values apply to all ages.

Interpretation

A positive result indicates intrathecal synthesis of antibody and is indicative of neurological infection.

Clinical Reference

1. Gonzalez-Scarano F, Nathanson N: Bunyaviruses. In Fields Virology. Vol. 1. Second edition. Edited by BM Fields, DM Knipe. New York, Raven Press, 1990, pp 1195-1228

2. Donat JF, Rhodes KH, Groover RV, Smith TF: Etiology and outcome in 42 children with acute nonbacterial meningoencephalitis. Mayo Clin Proc 1980:55:156-160

3. Tsai TF: Arboviruses. In Manual of Clinical Microbiology. Seventh edition. Edited by PR Murray, EF Baron, MA Pfaller, et al. Washington, DC, ASM Press, 1999, pp 1107-1124

4. Calisher CH: Medically important arboviruses of the United States and Canada. Clin Microbiol Rev 1994;7:89-116

Day(s) and Time(s) Performed

May through October: Monday through Friday; 9 a.m.

 

November through April: Monday, Wednesday, Friday; 9 a.m.

Analytic Time

Same day/1 day

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

86651 x 2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CAVPC Calif(LaCrosse) Encep Ab Panel, CSF In Process

 

Result ID Test Result Name Result LOINC Value
26365 Calif(LaCrosse) Encep Ab, IgG,CSF 9539-8
26366 Calif(LaCrosse) Encep Ab, IgM,CSF 9540-6