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Test ID ARBOP Arbovirus Antibody Panel, IgG and IgM, Serum

Useful For

Aiding the diagnosis of arboviral encephalitis (California [LaCrosse], St. Louis, Eastern equine and Western equine encephalitis)

Profile Information

Test ID Reporting Name Available Separately Always Performed
CAVP Calif Virus (LaCrosse)IgG and IgM,S Yes Yes
EEEP East Equine Enceph Ab, IgG and IgM, S Yes Yes
STLP St. Louis Enceph Ab, IgG and IgM, S Yes Yes
WEEP West Equine Enceph Ab,IgG and IgM,S Yes Yes

Method Name

Immunofluorescence Assay (IFA)

Reporting Name

Arbovirus Ab Panel IgG and IgM, S

Specimen Type

Serum


Advisory Information


This panel tests for 4 arboviruses; to test for a specific arbovirus, the following tests are individually orderable:

-CAVP / California Virus (La Crosse) Encephalitis Antibody Panel, IgG and IgM, Serum

-EEEP / Eastern Equine Encephalitis Antibody Panel, IgG and IgM, Serum

-STLP / St. Louis Encephalitis Antibody Panel, IgG and IgM, Serum

-WEEP / Western Equine Encephalitis Antibody Panel, IgG and IgM, Serum



Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL


Specimen Minimum Volume

0.15 mL

Specimen Stability Information

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

Clinical Information

California (LaCrosse) Virus:

California (LaCrosse) virus is a member of the Bunyaviridae family and is one 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 less than 15 years of age, usually from rural areas. The incubation period is estimated to be 7 days and acute illness lasts 10 days or less in most instances. Typically, the first symptoms are nonspecific, lasting 1 to 3 days, and are followed by the appearance of central nervous system (CNS) signs and symptoms such as stiff neck, lethargy, and seizures, which usually abate within 1 week. Symptomatic infection is almost never recognized in those over 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 (no more than 2%) of patients. Learning performance and behavior of most recovered patients are not distinguishable from comparison groups in these same areas.

 

Eastern Equine Encephalitis (EEE):

EEE is within the alphavirus group. It is a low prevalence cause of human disease in the eastern and Gulf Coast states. EEE is maintained by a cycle of mosquito/wild bird transmission, peaking in the summer and early fall, when man may become an adventitious host. The most common clinically apparent manifestation is a mild undifferentiated febrile illness, usually with headache. CNS involvement is demonstrated in only a minority of infected individuals, it is more abrupt and more severe than with other arboviruses, with children being more susceptible to severe disease. Fatality rates are approximately 70%.

 

St. Louis Encephalitis (SLE):

Areas of outbreaks of SLE since 1933 have involved the western United States, Texas, the Ohio-Mississippi Valley, and Florida. The vector of transmission is the mosquito. Peak incidence occurs in summer and early autumn. Disease onset is characterized by generalized malaise, fever, chills, headache, drowsiness, nausea, and sore throat or cough, followed in 1 to 4 days by meningeal and neurologic signs. The severity of illness increases with advancing age; persons over 60 years have the highest frequency of encephalitis. Symptoms of irritability, sleeplessness, depression, memory loss, and headaches can last up to 3 years.

 

Western Equine Encephalitis (WEE):

The virus that causes WEE is widely distributed throughout the United States and Canada; disease occurs almost exclusively in the western states and Canadian provinces. The relative absence of the disease in the eastern United States probably reflects a paucity of the vector mosquito species, Culex tarsalis, and possibly a lower pathogenicity of local virus strains. The disease usually begins suddenly with malaise, fever, and headache, often with nausea and vomiting. Vertigo, photophobia, sore throat, respiratory symptoms, abdominal pain, and myalgia are also common. Over a few days, the headache intensifies; drowsiness and restlessness may merge into a coma in severe cases. In infants and children, the onset may be more abrupt than for adults. WEE should be suspected in any case of febrile CNS disease from an endemic area. Infants are highly susceptible to CNS disease and about 20% of cases are under 1 year of age. There is an excess of males with WEE clinical encephalitis, averaging about twice the number of infections detected in females. After recovery from the acute disease, patients may require from several months to 2 years to overcome the fatigue, headache, and irritability. Infants and children are at higher risk of permanent brain damage after recovery than adults.

Reference Values

CALIFORNIA VIRUS (La CROSSE) ENCEPHALITIS ANTIBODY

IgG: <1:10

IgM: <1:10 

Reference values apply to all ages.

 

EASTERN EQUINE ENCEPHALITIS ANTIBODY

IgG: <1:10

IgM: <1:10 

Reference values apply to all ages.

 

ST. LOUIS ENCEPHALITIS ANTIBODY

IgG: <1:10

IgM: <1:10 

Reference values apply to all ages.

 

WESTERN EQUINE ENCEPHALITIS

IgG: <1:10

IgM: <1:10 

Reference values apply to all ages.

Interpretation

In patients infected with these or related viruses, IgM class antibody is reliably detected within 1 to 3 weeks of onset, peaking and rapidly declining within 3 months. Results from a single serum specimen can differentiate early (acute) infection from past infection with immunity if IgM is positive (suggests acute infection).

 

IgG antibody is generally detectable within 1 to 3 weeks of onset, peaking within 1 to 2 months, and declining slowly thereafter. A single serum specimen IgG of 1:10 or greater indicates exposure to the virus. A 4-fold or greater rise in IgG antibody titer in acute and convalescent sera indicates recent infection.

 

In the United States, it is unusual for any patient to show positive reactions to more than 1 of the arboviral antigens, although Western equine encephalitis and Eastern equine encephalitis antigens will show a noticeable cross-reactivity.

Clinical Reference

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

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

3. Tsai TF: Arboviruses. In Manual of Clinical Microbiology. Seventh edition. Edited by PR Murray, EJ Baron, MA Pfaller, et al: Washington, DC, American Society for Microbiology, 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

CPT Code Information

86651 x 2-California virus (La Crosse) encephalitis antibody, IgG and IgM

86652 x 2-Eastern equine encephalitis antibody, IgG and IgM

86653 x 2-St. Louis encephalitis antibody, IgG and IgM

86654 x 2-Western equine encephalitis antibody, IgG and IgM

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ARBOP Arbovirus Ab Panel IgG and IgM, S 49093-8

 

Result ID Test Result Name Result LOINC Value
8764 Calif (LaCrosse) Encep Ab, IgG, S 10904-1
83354 East Equine Enceph Ab, IgG, S 10896-9
8182 St. Louis Enceph Ab, IgG, S 10906-6
8193 West Equine Enceph Ab, IgG, S 6957-5
87279 West Equine Enceph Ab, IgM, S 6958-3
87268 St. Louis Enceph Ab, IgM, S 10907-4
83355 East Equine Enceph Ab, IgM, S 10898-5
87280 Calif (LaCrosse) Encep Ab, IgM, S 10905-8

Test Classification

This test has been cleared, approved or is exempt by the U.S. 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.

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Testing Algorithm

The following algorithms are available in Special Instructions:

-Meningitis/Encephalitis Panel Algorithm

-Mosquito-borne Disease Laboratory Testing