McDonald’s Sales Slump After E. Coli Outbreak Spooks Diners (1)

McDonald’s Corp. sales plummeted following news of E. coli infections linked to the chain’s Quarter Pounders.

Transactions fell as much as 6% from the prior year in the days after the outbreak became public on Tuesday, dragging down total sales, according to Bloomberg Second Measure data through Oct. 25. The group tracks debit and credit card transactions from US consumers.

The outbreak dealt a blow to McDonald’s, which had been working to reverse slumping traffic with offers such as a $5 meal deal and a splashy marketing campaign behind the limited-time Chicken Big Mac. McDonald’s transactions had been growing in ...