A cyclospora outbreak is affecting thousands of Americans, and federal investigators are having trouble tracing the source. The parasite does not provide any usable samples for lab testing, making it hard to track. Patient interviews are being relied on to gather information, as there is no other way to confirm the illness.

This approach is being used because the parasite does not leave behind any identifiable genetic material. Further details on the outbreak and investigation are available from federal investigators and health experts, who are working to learn more about the source of the illness.