The bacterium called Enterobacter sakazakii, thought to have caused a number of meningitis outbreaks at children's hospitals in the US and Europe, has been found in powdered infant formula before, but this study is the first to detect it in dried infant food, reports the New Scientist this week.
Although there are only a few cases each year, the death rate from infection can be as high as one-third. Premature babies and those with a weakened immune system are at particular risk.
Carol Iversen and colleagues at Nottingham Trent University in the UK analysed more than 200 samples from 110 different products, including powdered infant formula, dried infant food and milk powder, bought in seven European countries, the US, South Korea and South Africa.
Eight out of 82 powdered infant formula samples contained stomach bacteria, as did 12 out of 49 dried infant food samples. Thirteen of the bacterial species they identified, including E. sakazakii, are members of the Enterobacteriaceae, associated with hospital-acquired infections, according to the report.
Iversen noted that manufacturers did not claim the products were completely free of pathogens but that many parents and nurses assume they are.
An outbreak of meningitis at a neonatal intensive care unit in Tennessee in 2001 was traced to a batch of powdered infant formula. One baby died and eight others were infected. The incident prompted the Centers for Disease Control in Atlanta, Georgia, to warn US doctors about the potential dangers of powdered formula.
The survey findings were presented at a meeting of the American Society for Microbiology in New Orleans last week.