At least 378 people in 16 states were sickened in a noted uptick in cyclospora infections between early June and early July, according to the latest numbers from the U.S. Centers for Disease Control and Prevention. Cyclospora has now sickened at least 221 people in Iowa and Nebraska, where the illnesses have been found to be part of the same outbreak linked to nationally distributed bagged salad mix. Investigators have yet to determine whether the remaining illnesses, spread across another 14 states, are connected to Iowa and Nebraska or should be treated as isolated outbreaks. Another issue left unclear is the brand name of the salad mix, or where it came from, a level of nondisclosure being criticized by food safety advocates such as Barfblog publisher Douglas Powell and food safety attorney and Food Safety News publisher Bill Marler. “The public has a right to know and to use the information as it sees fit,” Marler told USA Today, “and people — especially government employees — have no right to decide what we should and should not know.” Officials in Iowa and Nebraska said the salad mix has expired and is no longer on store shelves; therefore it is not classified as a public health threat. Investigators at the U.S. Food and Drug Administration have now taken over the effort to trace back each individual ingredient in the salad mix in hopes of finding the original contaminant source. Speaking to Food Safety News last week, former Minnesota state epidemiologist Dr. Michael Osterholm criticized the investigation’s speed, saying that the farm responsible for the contamination might still ship out additional contaminated products if not identified as soon as possible. “I recognize it’s frustrating when we’re not able to give all the information people want at this point in the outbreak investigation,” said CDC spokeswoman Barbara Reynolds, “however what we have learned from Iowa and Nebraska gives us a strong lead on a possible source for the outbreak.” Speaking on behalf of FDA, Douglas Karas told Food Safety News the agency will take necessary preventive action against the source of contamination upon identifying it. “FDA is following the strongest leads provided by the states and has prioritized the ingredients of the salad mix identified by Iowa for the traceback investigation, but is following other leads as well,” he said “This is labor-intensive and painstaking work, requiring the collection, review and analysis of hundreds and at times thousands of invoices and shipping documents,” he continued. Karas said FDA has dedicated seven staff members from its headquarters to solving the outbreak, along with several specialists in 10 field offices around the country. Cyclospora is a single-celled parasite that usually gets on food via contaminated water and outbreaks are often associated with fresh produce. Symptoms appear anywhere from several days to weeks after exposure and include watery diarrhea, vomiting, stomach cramps, fatigue, muscle aches and fever. Helena Bottemiller contributed reporting to this story.