As health officials continue investigating a multistate cyclospora outbreak linked to recalled iceberg lettuce, many Americans may be wondering how long it will take before the outbreak is over. What to Know About Cyclospora Outbreak in U.S.A cyclospora outbreak has spread across the United States this summer, with the Centers for Disease Control and Prevention (CDC) reporting 1,645 confirmed cases and 141 hospitalizations. When Will Cyclospora Outbreak End? Hanage said the ongoing cyclospora outbreak will last into August in the best-case scenario. Experts caution, however, that weather alone will not immediately halt an outbreak if contaminated food is already in circulation.