How Cronobacter is spread
Sometimes powdered formula gets germs in it while it is being made at the factory. Other times, Cronobacter can get into powdered infant formula after it is opened at home or somewhere else. Since Cronobacter germs live in the environment, there might be other ways babies can catch it. We do not know if Cronobacter infection can be spread from one person to another, but other types of bacteria spread this way, especially in hospitals if people do not wash their hands well.
Risks from factories and homes
Powdered infant formula is not germ-free. Formula manufacturers report that it is not possible to remove all germs from powdered infant formula. At the factory, Cronobacter could get into formula powder from ingredients used to make the formula or if the formula powder touches a Cronobacter-covered surface in the factory.
At home, Cronobacter could get into the formula if formula lids or scoops are placed on Cronobacter-covered surfaces and later touch the formula or if the formula is mixed with water or in a bottle that has Cronobacter in it.