The Food and Drug Administration has approved two new tests to screen whole blood and plasma supplies for the tickborne parasite Babesia microti.
The Imugen Babesia microti Arrayed Fluorescent Immunoassay (AFIA) detects antibodies to B. microti in human plasma samples and the Imugen Babesia microti Nucleic Acid Test (NAT) detects B. microti DNA in human whole blood samples. The tests can be used as donor screening tests on individual samples from donors of whole blood and blood components, as well as living organ and tissue donors, according to the FDA . The tests are not intended as a way to diagnose babesiosis infections.
B. microti is transmitted mainly by blacklegged or deer ticks and is responsible for babesiosis infection. There are about 1,000-2,000 cases of the infection reported in the United States annually, with most originating in the Northeast and upper Midwest. Babesiosis infection can result in flu-like symptoms, though most people are asymptomatic and are never diagnosed.
The new screening tests are the first approvals for B. microti detection. The tests have been available under investigational use since 2012. The tests are manufactured by Oxford Immunotec and are currently only available as in-house tests at the company’s Norwood, Mass., facility.
There is no FDA guidance for testing blood and plasma samples for B. microti, but the agency is planning to issue draft guidance later in 2018.