(UPDATED COVERAGE July 16) Investigators in Iowa are ready for federal agencies to pick up the ball in the multi-state cyclospora parasite-related outbreak saying they have eliminated Iowa-grown produce as the source.

UPDATED: Vegetables suspected as cause of cyclospora outbreak“We don’t believe it was an Iowa product because the cases are spread across the state and none of our (produce) farmers have that kind of distribution network,” said Steven Mandernach, bureau chief for food and consumer safety at Iowa’s Department of Inspections and Appeals.

As of July 16, Iowa’s Department of Health reported 81 confirmed cases — up 10 from the day before. In Nebraska, the case count was at 53 on July 16. Public health officials in both states believe fresh vegetables, not fruit, is the source.

An update from Dr. Joseph Acierno, Nebraska’s chief medical officer and director of public health, echoed comments from Iowa officials, saying that patient interviews, illness onset dates and the widespread nature of the outbreak suggest locally grown produce is not part of this outbreak.

“Interviews also show people’s symptoms started no later than the end of June, which suggests the contaminated food source may have worked its way through the system since fresh produce has a limited shelf life,” Acierno said in his update.

Iowa’s Mandernach said he and other Iowa officials have given all of their traceback investigation information to the Food and Drug Administration and the Centers for Disease Control and Prevention, which the state has been working with since the outbreak was discovered in late June.

“We told them yesterday afternoon in our call that we think it’s time to transition the investigation to the FDA and CDC and that we would like that to happen by mid-week.”

UPDATED: Vegetables suspected as cause of cyclospora outbreakOn July 15, CDC spokeswoman Sharon Hoskins said federal officials are assisting but that “Iowa and Nebraska are leading the investigation.”

Other states involved

Dr. Patricia Quinlisk, Iowa’s head epidemiologist and medical director of the state’s Health Department said at least two other states are investigating outbreaks caused by the rare cyclospora parasite, which is more common in other parts of the world than in the U.S.

“One (state) has a lot of cases, but they haven’t gone public yet,” Quinlisk said July 15.

Quinlisk said the first two cases were confirmed in Iowa in the last week of June. The Iowa outbreak update on July 16 was even more specific.

“Onset dates of the illness suggest the ill people had eaten the contaminated food in mid-June. This is a very good indication the food which was the source of the outbreak has already been consumed or discarded, since fresh vegetables have a limited shelf life. At no time was an Iowa-grown fruit or vegetable suspected to be the cause of the outbreak,” according to the update.

Symptoms usually begin about a week after exposure and can last more than 50 days in healthy people and up to a year in people with compromised immune systems, Quinlisk said. She said Iowa usually has one confirmed case annually, but there are possibly more because a specific lab test is required to detect the parasite.

The most recent widespread outbreak in North America caused by the parasite was in 1996 when more than 850 cases, mostly in 20 states in the U.S. but including some in Canada, were linked to imported raspberries from Guatemala, according to the CDC website. Fresh basil and lettuce have also been linked to U.S. outbreaks caused by the cyclospora parasite.