Arbovirus Antibody Panel, IgG and IgM (Sendout)

Useful For: Aiding the diagnosis of arboviral encephalitis. Includes IgG and IgM antibody testing for the following:

• California Virus (LaCrosse) encephalitis
• St. Louis encephalitis
• Eastern equine encephalitis
• Western equine encephalitis

Testing Algorithm:

• Mayo Meningitis/Encephalitis Panel Algorithm
• Mayo Mosquito-borne Disease Laboratory Testing

Reference Values:

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.

Cautions:

All results must be correlated with clinical history and other data available to the attending physician.

Since cross-reactivity with dengue fever virus does occur with St. Louis encephalitis antigens, and, therefore, cannot be differentiated further, the specific virus responsible for positive results may be deduced by the travel history of the patient, along with available medical and epidemiological data, unless the virus can be isolated.

Eastern and Western equine encephalitis viruses show some cross-reactivity; however, antibody response to the infecting virus is typically at least 8-fold higher.

CSF: False-positive results may be caused by breakdown of the blood-brain barrier, or by the introduction of blood into the cerebrospinal fluid (CSF) at collection.

Serum: Specimens collected within the first 2 weeks after onset are variably negative for IgG antibody and should not be used to exclude the diagnosis of arboviral disease. If arboviral infection is suspected, a second specimen should be collected and tested 10 to 21 days later.

Blood: Collect 3 mL blood in RED TOP tube or GOLD SST.

CSF: Collect 0.7 mL CSF in a sterile vial.

Outside Laboratories:

• CSF: Collect 0.7 mL CSF in a sterile vial. Refrigerate CSF.
• Blood: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To (Serum Only): Gross hemolysis, gross lipemia.

• Blood: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.
• CSF: Refrigerate CSF.

Login: SEND1-;REFRIG

• RSNDT1: MAYOSD
• RSTYP1: SRM or CSF
• RTSRQ1: [Select test below]
  • ;Arbovirus Ab Panel, IgG & IgM, Serum (Mayo Test ARBOP)
  • ;Arbovirus Ab Panel, IgG & IgM, CSF (Mayo Test ABOPC)

Sendouts: Order appropriate Mayo test based on sample type received.

• Serum: Order ARBOP.
• CSF: Order ABOPC.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To (Serum Only): Gross hemolysis, gross lipemia.

CPTs:

• 86651(x2) - California virus (La Crosse) encephalitis antibody, IgG and IgM
• 86652(x2) - Eastern equine encephalitis antibody, IgG and IgM
• 86653(x2) - St. Louis encephalitis antibody, IgG and IgM
• 86654(x2) - Western equine encephalitis antibody, IgG and IgM