BRUSSELS, July 2 -- By the time health officials in fourteen countries began comparing case reports, the connecting thread was something found in nearly every European kitchen: a packet of flavoured instant noodles. At least 106 people have been confirmed sick across the continent, 49 of them hospitalized, with a Salmonella strain that European food safety authorities have traced to a single Ukrainian manufacturer.

The European Centre for Disease Prevention and Control and the European Food Safety Authority confirmed Thursday that products made by Euro Food Service, sold under the Reeva Foods brand, are the most likely source of the outbreak. Both agencies identified Salmonella Stanley, a strain historically associated with food producti...