Possible <scp>NAT</scp> ‐negative transfusion‐transmitted <i>Babesia microti</i>

This reverse-notification TTB case was unlikely to have been the result of either a product from an asymptomatic untested donor from a non-endemic state infected during travel to an endemic area or a tick-borne infection of the transfusion recipient. More likely, TTB resulted from transfusion of a NAT-negative unit donated 3 months prior to the involved donor's subsequent NAT-positive collection. To our knowledge, this is the first reported potential Babesia NAT failure.