Foodborne Botulism Outbreak After Consumption of Home-Canned Cactus (Nopales) - Fresno County, California, June 2024

Foodborne botulism is a rare and potentially fatal illness caused by ingestion of food containing botulinum neurotoxin produced by the bacterium Clostridium botulinum or other neurotoxigenic Clostridium species. C. botulinum can grow in improperly prepared or stored food items such as home-canned or home-preserved vegetables. On June 25, 2024, the Fresno County Department of Public Health and California Department of Public Health, in collaboration with CDC and two local hospitals, initiated an investigation of a foodborne botulism outbreak linked to two related family gatherings in Fresno County, California. A total of 31 persons attended one or both gatherings. Eight attendees had symptoms compatible with botulism and received botulism antitoxin; five of eight had botulinum neurotoxin type A (BoNT/A) detected in serum. Patients had hospital stays ranging from 2 to 42 days, six patients were admitted to an intensive care unit, and two required invasive mechanical ventilation; all survived. Epidemiologic investigation identified home-preserved prickly pear cactus pads (nopales) included in a homemade salad and served at both events as a food item of interest; laboratory testing confirmed the nopales salad as the source of BoNT/A. This foodborne botulism outbreak is the first reported to be linked to home canning of nopales, a popular vegetable used in traditional Mexican cuisine. Rapid public health coordination is essential for responses to foodborne botulism outbreaks. Enhancing community and clinician awareness of foodborne botulism by increasing access to culturally and linguistically accessible home food preservation and canning guidelines might help prevent future outbreaks.