ATLANTA (AP) — An Oklahoma baby is the third infant this month sickened by a rare type of bacteria sometimes associated with tainted powdered infant formula.

The child, from Tulsa County, was infected with Cronobacter sakazakii but fully recovered, health officials said Wednesday. An Illinois child also rebounded after being sickened by the bacteria. A Missouri infant who was 10 days old died.

The Missouri child, Avery Cornett of Lebanon, had consumed Enfamil Newborn powdered infant formula made by Illinois-based Mead Johnson. Powdered formula has been suspected in illnesses caused by the bacteria in years past.

But health officials say the Oklahoma child had not consumed Enfamil. And Mead Johnson this week reported that its own testing found no bacteria in the product.

U.S. officials are awaiting results from their own testing of powdered formula and distilled water — also known as 'nursery water' — used to prepare it.

The cases occurred in roughly the same region of the country. At this point, it's not clear that they are connected, said Barbara Reynolds, a Centers for Disease Control and Prevention spokeswoman.

Symptoms can include irritability, lethargy, fever, vomiting and seizures. The infection can be treated with antibiotics, but it's still deemed extremely dangerous to babies less than 1 month old and those born premature. An estimated 40 percent of illnesses from the bacteria end in death.

There are no legal requirements that cases be reported, but the CDC gets roughly four to six reports of Cronobacter sakazakii each year. There have been 10 this year, but that doesn't necessarily mean cases are increasing. Attention over the Missouri death just may have prompted more reporting in the past, health officials said.

That's what happened in the Oklahoma case. That child got sick earlier in December, but after Avery Cornett's death, the case "took on added significance" and was reported, said Larry Weatherford, a spokesman for the Oklahoma State Department of Health.

The bacteria is found naturally in the environment and in plants such as wheat and rice, but in the past also has been traced to dried milk and powdered formula. 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.

After initial suspicion landed on Enfamil, national retailers including Wal-Mart Stores Inc., Walgreen Co., Kroger Co. and Safeway pulled a batch of the powdered infant formula from their shelves.