Outbreak of serotype Poona in infants linked to persistent contamination in an infant formula manufacturing facility, France, August 2018 to February 2019.

We describe a Poona outbreak involving 31 infant cases in France. Following outbreak detection on 18 January 2019, consumption of rice-based infant formula manufactured at a facility in Spain was identified as the probable cause, leading to a recall on 24 January. Whole genome sequencing analysis linked present outbreak isolates to a 2010-11 Poona outbreak in Spain associated with formula manufactured in the same facility, indicating a persistent source of contamination.