LINCOLN, Neb. — Health officials in Iowa and Nebraska on Tuesday identified prepackaged salad mix as the source of a severe stomach bug that sickened hundreds of people in both states, but federal authorities said it's not clear whether cyclospora outbreaks elsewhere in the U.S. are also linked to that produce.
Cyclospora is a rare parasite that causes a lengthy gastrointestinal illness, and outbreaks of the illness have been reported in 15 states. The U.S. Centers for Disease Control and Prevention said Tuesday that it's not clear whether all of the illnesses are linked to a single source. The outbreak has sickened at least 145 residents in Iowa and 78 in Nebraska.
Nebraska officials said the salad mix in question included iceberg and romaine lettuce, along with red cabbage and carrots, which came through national distribution chains. They did not identify specific brands. A Nebraska health department spokeswoman said the agency was working with the U.S. Food and Drug Administration to get a "clear picture" of which were involved and whether they're tied to one common source, such as the same farm or producer.
"Our goal is to protect Nebraskans, pinpoint the source of the illness and make sure the risk is eliminated," said Dr. Joseph Acierno, the department's chief medical officer and director of public health.
In Iowa, officials said they were confident that most if not all of the product was no longer on the shelves. The affected products were traced to grocery stores and restaurants, said Steven Mandernach, the state's top food-safety inspector. Mandernach said cases were reported throughout the state, but the largest number was in the eastern Iowa city of Cedar Rapids.
Mandernach said officials have traced 80 percent of the Iowa cases to a common source, which he did not identify because officials believe there's no longer any immediate safety threat. Mandernach said it's possible that the parasite spread through contaminated floodwater and onto farm fields after arriving in the state. Before the outbreak, he said, Iowa had seen about 20 cases of cyclospora in the last decade.
Local health departments are working with the U.S. Food and Drug Administration to identify exactly where the contamination originated in the food production chain and where the product was distributed.
The CDC says 372 cases of the cyclospora infection, which causes diarrhea and other flu-like symptoms, have been reported in 15 states: Iowa, Texas, Nebraska, Florida, Wisconsin, Illinois, New York, Georgia, Missouri, Arkansas, Connecticut, Kansas, Minnesota, New Jersey and Ohio.
The CDC said at least 21 people have been hospitalized and most of the reported illnesses occurred from mid-June to early July. The CDC and the Food and Drug Administration are investigating the cyclospora infections but have not yet pointed to a source.
"CDC is still actively pursuing all leads and hasn't implicated any single food item as the cause of the outbreak in all states," said CDC spokeswoman Sharon Hoskins. "We're still not sure if the cases in all of the states are linked to the same outbreak."
Hoskins said that in some previous outbreaks of cyclospora, the cause was never discovered. The illness is rare in the United States but is sometimes contracted abroad or from imported food, according to the CDC.
The FDA said investigators are trying to trace the paths of food eaten by those who fell ill. That process is "labor intensive and painstaking work, requiring the collection, review and analysis of hundreds and at times thousands of invoices and shipping documents," the FDA said.
The agency said it has a seven person team in its Maryland headquarters and specialists in 10 field offices across the country working to identify the source of the outbreak.
Cyclospora illnesses are spread when people ingest food or water contaminated with feces. The illnesses are most often found in tropical or subtropical countries and have been linked to imported fresh fruits and vegetables in the past.
In Texas, public health officials have received 122 reports of the illness but have not yet found a link. The state issued an advisory that urged health care providers to test patients if they show symptoms of the infection, said Christine Mann, a spokeswoman for the Texas Department of State Health Services.
Connecticut has two reported cases, state Department of Public Health spokesman William Gerrish said Tuesday. Gerrish said the agency interviewed the two people to determine if there is any relation to the national outbreak. One patient likely acquired the infection while traveling internationally and the case is not related to the multistate outbreak, he said
In Kansas, state health department spokeswoman Miranda Steele said two cyclospora cases were tied to the outbreak. Steele said officials there believe both illnesses were caused by food eaten in Nebraska.
Jalonick contributed from Washington, D.C. Associated Press writers Nomaan Merchant in Dallas, Stephen Singer, in Hartford, Conn., and Roxana Hegeman in Wichita, Kan., contributed to this report.