Most food recalls happen after people start getting sick, a company or agency working backward from real illness reports to find the source. Panorama Produce pulled hundreds of boxes of mangoes from Walmart shelves in the Northeast before a single reported illness, based entirely on testing done somewhere else in the supply chain. The recall covers 302 boxes of size 9 mangoes, packaged under the Martina brand, according to a notice Panorama Produce filed with the FDA on Aug. The affected fruit was distributed to select Walmart stores in Connecticut, New York, New Jersey, and Pennsylvania, and sold there between Aug. The answer traces back to a routine test result on fruit that never even reached a store shelf.