Test Code MISC2MAYOEEEP Eastern Equine Encephalitis Antibody, IgG and IgM, Serum
Useful For
Aiding in the diagnosis of Eastern equine encephalitis
Method Name
Immunofluorescence Assay (IFA)
Reporting Name
East Equine Enceph Ab, IgG and IgM, SSpecimen Type
SerumSpecimen 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 |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Clinical Information
Eastern equine encephalitis (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.
Central nervous system involvement is demonstrated in only a minority of infected individuals; it is more abrupt and more severe with EEE than other arboviruses, with children being more susceptible to severe disease. Fatality rates are approximately 70% for EEE.
Reference Values
IgG: <1:10
IgM: <1:10
Reference values apply to all ages.
Interpretation
In patients infected with this virus, 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 greater than or equal to 1:10 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 indicate 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.
Infections can occur at any age. The age distribution depends on the degree of exposure to the particular transmitting arthropod relating to age and sex, as well as the occupational, vocational, and recreational habits of the individuals. Once humans have been infected, the severity of the host response may be influenced by age.
Method Description
Dilutions of test sera are prepared and allowed to react with substrate cells infected with Eastern equine encephalitis virus. If IgG antibodies to this virus are present in the serum of the patient, an antigen-antibody complex will develop that can be detected by a fluorescein-labeled antibody directed to human globulin.(Tsai TF: Arboviruses. In: Murray PR, Baron EJ, Pfaller MA, et al, eds. Manual of Clinical Microbiology. 7th ed. ASM Press, 1999; 1107-1124; Beaty BJ, Casals J, Brown KL, et al: Indirect fluorescent-antibody technique for serological diagnosis of LaCrosse [California] virus infections. J Clin Microbiol. 1982;15:429-434; Beckham JD, Tyler KL: Arbovirus Infections. Continuum (Minneap Minn). 2015 Dec;21(6 Neuroinfectious Disease):1599-1611. doi: 10.1212/CON.0000000000000240)
Day(s) Performed
May through October: Monday through Friday
November through April: Monday, Wednesday, Friday
Report Available
Same day/1 to 4 daysPerforming Laboratory

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
86652 x 2
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
EEEP | East Equine Enceph Ab, IgG and IgM, S | 69034-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
83354 | East Equine Enceph Ab, IgG, S | 10896-9 |
83355 | East Equine Enceph Ab, IgM, S | 10898-5 |
Secondary ID
83155Forms
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.
Testing Algorithm
See Mosquito-borne Disease Laboratory Testing in Special Instructions.