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Test Code CAVP California Virus (La Crosse) IgG and IgM, Serum

Useful For

Aiding the diagnosis of California (La Crosse) encephalitis using serum specimens

Method Name

Immunofluorescence Assay (IFA)

Reporting Name

Calif Virus (LaCrosse)IgG and IgM,S

Specimen Type

Serum


Ordering Guidance


This assay detects only California virus. For a complete arbovirus panel, order ARBOP / Arbovirus Antibody Panel, IgG and IgM, Serum.



Specimen Required


Supplies: Sarstedt Aliquot Tube 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Specimen Minimum Volume

0.15 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reference Values

IgG: <1:10

IgM: <1:10

Reference values apply to all ages.

Interpretation

In patients infected with these or related viruses, IgG antibody is generally detectable within 1 to 3 weeks of onset, peaking within 1 to 2 months and declining slowly thereafter.

 

IgM class antibody is also reliably detected within 1 to 3 weeks of onset, peaking and rapidly declining within 3 months.

 

Single serum specimen IgG of 1:10 or greater indicates exposure to the virus.

 

Results from a single serum specimen can differentiate early (acute) infection from past infection with immunity if IgM is positive (suggests acute infection).

 

A 4-fold or greater rise in IgG antibody titer in acute and convalescent sera indicates recent infection.

Clinical Reference

1. Gonzalez-Scarano F, Nathanson N: Bunyaviruses. In: Fields BN, Knipe DM, eds. Fields Virology. Vol 1. 2nd ed. Raven Press; 1990:1195-1228

2. Donat JF, Rhodes KH, Groover RV, Smith TF, Etiology and outcome in 42 children with acute nonbacterial meningoencephalitis. Mayo Clin Proc. 1980;55(3):156-160

3. Tsai TF. Arboviruses. In: Murray PR, Baron EJ, Pfaller MA, et al, eds. Manual of Clinical Microbiology. 7th ed. American Society for Microbiology; 1999:1107-1124

4. Calisher CH. Medically important arboviruses of the United States and Canada. Clin Microbiol Rev. 1994;7(1):89-116

5. Dolin R. California encephalitis, hantavirus pulmonary syndrome, hantavirus hemorrhagic fever with renal syndrome, and bunyavirus hemorrhagic fevers. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:2169-2176

Day(s) Performed

Monday through Friday

Report Available

Same day/1 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

86651 x 2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CAVP Calif Virus (LaCrosse)IgG and IgM,S 96499-9

 

Result ID Test Result Name Result LOINC Value
8764 Calif (LaCrosse) Encep Ab, IgG, S In Process
87280 Calif (LaCrosse) Encep Ab, IgM, S In Process

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Testing Algorithm

For more information see Mosquito-borne Disease Laboratory Testing.