Public health officials are trying to find the source of the salmonella poisoning that infected a Jackson County boy who is Oregon’s 10th confirmed case in a national outbreak.

Public health officials are trying to find the source of the salmonella poisoning that infected a Jackson County boy who is Oregon's 10th confirmed case in a national outbreak.

State officials confirmed Tuesday that the boy fell ill from the same bacteria that has sickened some 500 people across the nation and forced the recall of everything from peanut butter crackers to pet treats.

The Oregon Public Health Division declined to release any information about the boy, including his age and hometown, to protect his privacy.

June Bancroft, a state epidemiologist, said investigators still don’t know what the boy ate that caused him to be sick, other than that “he ate something with peanut butter.”

More than 200 products that contain peanut butter or peanut paste have been recalled since investigators traced the source of the outbreak to a Peanut Corporation of America plant in Blakely, Ga. Federal officials have said Peanut Corporation of America sold the peanut butter only to industrial customers who used it to make other products.

Peanut butter sold in jars for individual consumption remains safe to eat.

Bancroft said connecting cases of salmonella with an outbreak from a single source can be difficult because it’s an illness that occurs periodically when people eat contaminated food. Some people experience violent diarrhea, fever and abdominal cramps, but the illness typically resolves itself within a few days, and many people who fall ill recover without seeking medical attention. Others are infected, but have only mild symptoms.

She said Oregon has about 400 cases of salmonella poisoning per year that are confirmed, but public health officials suspect there are many more cases they never hear about. Some say that for every reported case, 20 others go unnoticed.

“They just sit at home and suffer,” Bancroft said.

Epidemiologists have sophisticated tools for determining whether a case of salmonella is connected with an outbreak. Researchers collect stool samples from people who are suspected of being infected, and send the samples to a lab for culturing. Researchers compare genetic material from cultured bacteria with the genetic material from the Salmonella typhimurium bacteria that has caused this outbreak.

If they match, the individual's illness becomes part of the outbreak, but there's a delay of two to three weeks between the time someone gets sick and laboratory analysis is complete. Bancroft said the Jackson County boy's sample was collected on Jan. 13.

She said Oregon had five cases in this outbreak before Dec. 1. No cases surfaced during December, but five have been identified since Jan. 1. Besides the new Jackson County case, there have been three in Clackamas County, two in Multnomah, one in Washington, two in Baker and one in Lane.

Washington has had 13 cases; Idaho, 11; and California, 62. To read more, see the federal Centers for Disease Control and Prevention Web site at www.cdc.gov.

Reach reporter Bill Kettler at 776-4492 or e-mail bkettler@mailtribune.com.