The tests can distinguish Babesia microti antibodies in plasma samples, and the in whole blood samples.
The US Food and Drug Administration (FDA) has granted approval of 2 tests from Imugen with the ability to detect antibodies to Babesia microti (B. microti) in human plasma samples and B. microti DNA in human whole blood samples.
The Babesia microti Arrayed Fluorescent Immunoassay (AFIA) can distinguish antibodies in plasma samples, and the Babesia microti Nucleic Acid Test (NAT) can perceive B. microti DNA in whole samples. Notably, the tests are not intended for use in the diagnosis of babesiosis infections.
“The US blood supply remains the safest in the world thanks in part to the FDA’s ongoing work to enforce standards for blood collection and to identify and respond to potential threats to the nation’s blood supply.,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement. “While babesiosis is both preventable and treatable, until today, there was no way to screen for infections amongst blood donors. Today’s actions represent the first approvals of Babesia detection tests for use in screening donors of whole blood and blood components, and other living donors.”
Both tests are intended for donor screening, using samples from individual human donors. That population includes volunteer donors of whole blood and blood components, and those that are living organ and tissue donors, according to the FDA.
Babesia parasites cause babesiosis, which commonly is asymptomatic in most individuals, and can be destructive for those individuals with severe infection. Spread by the black-legged tick, transmission of the virus via blood transfusion is rare, although the FDA acknowledged that “it is the most frequently reported transfusion-transmitted parasitic infection in the United States and remains an important concern.”
Babesiosis impacts between 1000 and 2000 patients in the US each year, the majority of which infections occur in the Northeast or upper Midwest portions of the United States.
"The investigational use of Babesia donor testing has been in place since August 2012 in selected Babesia-endemic areas under investigational new drug applications. The use of the investigational tests has resulted in the removal of a significant number of infected units from the blood supply,” according to the FDA.
Data collected from testing and additional studies performed by the manufacturer reportedly prevented the release of hundreds of possibly infectious donations, according to the FDA, and validated the tests as efficacious in screening donors for B. microti infection.
Although no FDA guidance for the testing of donor samples for Babesia currently exists, draft guidance with recommendations for reducing the risk of transfusion-transmitted babesiosis will be released by the FDA later this year.
The approval of the Imugen Babesia microti AFIA and NAT tests was granted to Oxford Immunotec, Inc. Both assays are in-house tests that can only be performed at the Norwood, Massachusetts facility.
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