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HelpTest ID STLP St. Louis Encephalitis Antibody, IgG and IgM, Serum
Useful For
Aiding in the diagnosis of St. Louis encephalitis
Method Name
Immunofluorescence Assay (IFA)
Reporting Name
St. Louis Enceph Ab, IgG and IgM, SSpecimen Type
SerumContainer/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 14 days |
| Frozen | 14 days |
Clinical Information
Onset is characterized by generalized malaise, fever, chilliness, headache, drowsiness, nausea, and sore throat or cough followed in 1 to 4 days by the 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. Areas of outbreaks since 1933 have involved the western United States, Texas, the Ohio-Mississippi Valley, and Florida. The vector of transmission is the mosquito. Peak incidence of St. Louis encephalitis is associated with summer and early autumn.
Reference Values
IgG: <1:10
IgM: <1:10
Cautions
All results must be correlated with clinical history and other data available to the attending physician.
Specimens drawn within the first 2 weeks after onset are variably negative for IgG antibody and should not be used to exclude the diagnosis of St. Louis encephalitis (SLE). If SLE is suspected, a second specimen should be drawn and tested 10 to 21 days later.
Since cross-reactivity with dengue fever does occur with SLE antigens, and, therefore, cannot be differentiated further. The specific virus responsible for such a titer may be deduced by the travel history of the patient, along with available medical and epidemiological data, unless the virus can be isolated.
Usually, when an infection with an arbovirus is suspected, it is too late to isolate the virus or draw serum specimens to detect a rise of antibody titer.
Day(s) Performed
May through October: Monday through Friday; 9 a.m.
November through April: Monday, Wednesday, Friday; 9 a.m.
Report Available
Same day/1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test has been cleared or approved 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.CPT Code Information
86653 x 2