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Babesia duncani WA1 IgG IFA

Test Code: 30290
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Clinical and Procedure
Clinical Utility

The Babesia duncani WA1 IgG assay is used to detect antibodies due to infection of the tick-borne protozoa Babesia duncani in cases of diagnostic uncertainty or suspected chronic infection. The assay is performed by indirect fluorescent antibody (IFA) method. Titer values above the reference intervals are considered evidence of current infection or past infection (e.g. within the last year).

About Babesia

Babesiosis is caused by a protozoan parasite that infects red blood cells and is primarily transmitted through the bite of infected ticks. Babesia microti (B. microti) is the main species that has been found to cause disease in people, and B. duncani WA1 is an important secondary cause of Babesiosis in the United States. Babesiosis is a malaria-like illness wherein erythrocytes are infected and damaged by the parasite. Many people exhibit no signs of illness. Some develop non-specific flu-like symptoms. Babesiosis can be life-threatening, particularly for individuals who are elderly or young, do not have a spleen, have a weakened immune system or other serious health conditions (e.g., liver or kidney disease). Of recent concern is the increasing occurrence of blood-transfusion associated Babesiosis. Babesia is the most common blood transfusion associated parasite, yet there is no available blood donor screening assay. When clinical signs of Babesiosis coincide with either possible exposure to ticks or blood transfusion from a donor residing in an endemic region, serological testing by IFA is commonly used to support the diagnosis of Babesiosis.

The first isolate of B. duncani was found in the state of Washington, hence the name “WA1.” Until recently it was not known that B. duncani infects individuals from many regions of the U.S. and the world, although the highest seroprevalence rates are still seen in the Pacific Northwest. Infection by B. duncani cannot be diagnosed by patient blood smears or by blood culture, nor can it be detected by Babesia microti IgG IFA. Sera from patients shown to have been infected by the tick-borne pathogens B. microti, Rickettsia rickettsii and Borrelia burgdorferi were tested and found to be negative by the Babesia duncani WA1 IgG IFA assay.


Human IgG antibody to Babesia duncani (B. duncani) WA1 antigens are detected by an indirect fluorescent antibody (IFA) assay. Briefly, a slide coated with fixed, B. duncani infected red blood cells are incubated with the diluted human serum sample. If specific B. duncani antibodies are present, they remain bound, are then labeled by a fluorescein-labeled antibody conjugate, and then detected by fluorescence microscopy. This test was developed and its performance characteristics were determined by Viracor Eurofins.This test has not been cleared or approved by the U.S. Food and Drug Administration. Results should be used in conjunction with clinical findings, and should not form the sole basis for a diagnosis or treatment decision.


Sera from patients shown to have been infected by the tick-borne pathogens--Babesia microti, Rickettsia rickettsii and Borrelia burgdorferi--were tested and found to be negative by the B. duncani WA1 IgG IFA assay.

Turnaround Time

1-4 business days from receipt of specimen

Specimen Information
Specimen Type Order Code CPT Code NY Approved Volume Assay Range Special Instructions
serum 30290 86753 Yes

2 mL (min. 0.1mL)

1:256 - 1:1024 titer

  • Collect 4-5 mL whole blood in red top tube.
  • Centrifuge and transfer 2 mL serum to sterile, screw top tube.
  • Can be shipped at ambient or frozen temperature Monday through Friday.
  • Specimens shipped at ambient temperature must be received within 96 hrs. of collection.

Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name and collection date. A Viracor Eurofins test requisition form must accompany each specimen. Ship specimens FedEx Priority Overnight to: Viracor Eurofins, 18000 W 99th St., Lenexa, KS 66219.

Causes for Rejection

Specimens beyond their acceptable length of time from collection as listed in the specimen handling, or specimen types other than those listed.


Specimens are approved for testing in New York only when indicated in the Specimen Information field above.

The CPT codes provided are based on Viracor Eurofins' interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Viracor Eurofins assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.

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