KANSAS CITY, Mo. (AP) -- Four cases of infants sickened by a rare bacteria sometimes linked to powdered formula, including two who died, are not related and parents can continue using the products to feed their babies, two federal agencies announced Friday.
Scientists with the Centers for Disease Control and Prevention and the Food and Drug Administration tested various types of powdered infant formula and distilled water, known as nursing water, and found no cases of contamination by Cronobacter sakazakii.
Four babies, including one in Missouri and another in Florida who died, were sickened by the bacteria that are found naturally in the environment and in plants such as wheat and rice. Cronobacter also has been traced to dried milk and powdered formula.
Two other babies, in Illinois and Oklahoma, were sickened by the bacteria but survived.
The Missouri baby, Avery Cornett of Lebanon, Mo., died earlier this month after appearing lethargic and displaying what his family said were signs of a stomach ache. Tests at a Springfield hospital showed he had Cronobacter, and he died a few days later after being removed from life support.
The infection can be treated with antibiotics, but it's deemed extremely dangerous to babies less than 1 month old and those born premature.
Avery's death prompted the CDC to ask public health officials from around the country to look for other cases of Cronobacter infection among infants. That request generated reports from three other states about their cases.
Avery's case also prompted Wal-Mart and several other national retailers to pull Enfamil Newborn formula, which Avery had consumed before getting sick, from 3,000 stores until the batches could be tested for contamination. Those tests came back negative, CDC announced Friday.
"The FDA tested factory sealed containers of powdered infant formula and nursery water with the same lot numbers as the opened containers collected from Missouri and no Cronobacter bacteria were found," the FDA said.
Powdered infant formula is not sterile, and experts have said there are not adequate methods to completely remove or kill all bacteria that might creep into formula before or during production.
The FDA said it gets four to six reports a year of infant infections related to formula and has not found a powder that tested positive since 2002. The CDC said with recent increased awareness of the illness, it has received 12 cases in 2011.
"CDC laboratory tests of samples provided by the Missouri Department of Health and Senior Services found Cronobacter bacteria in an opened container of infant formula, an opened bottle of nursery water and prepared infant formula," the agency said Friday. "It is unclear how the contamination occurred."
CDC also tested bacteria in the Illinois case and found it differed genetically from that found in the Missouri case. It said bacteria from the Oklahoma and Florida cases were not available for testing.