1721. An Outbreak of Botulism Associated With Nacho Cheese Sauce From a Gas Station in California

Abstract Background Foodborne botulism is rare with 0–6 cases reported annually in California. During April 24–28, 2017, 4 hospitalized patients with suspect foodborne botulism were reported to the California Department of Public Health (CDPH) from 2 adjacent California counties. In collaboration with local public and environmental health, CDPH conducted an investigation to determine the magnitude of the outbreak, identify potential sources, and implement control measures. Methods A case was defined as clinical botulism in a visitor to or resident of Sacramento County with illness onset during April 20 to May 5, 2017. Case-patients or their proxies were interviewed. Patient specimens and suspect food items were tested for the presence of botulinum toxin and toxin-producing Clostridium botulinum; C. botulinum isolates underwent whole genome sequencing (WGS) at the CDPH laboratory. Results In April–May 2017, a total of 10 patients were hospitalized with laboratory-confirmed botulism. Median age was 34 years (range 16–57); 7 were male, and 8 were Latino. All patients required intensive care, 7 required ventilator support, and 1 died. Nine patients confirmed visiting Gas Station A in the week before illness onset; 8 reported consuming nacho cheese sauce served from a dispenser there. Inspection of Gas Station A on May 5 indicated that the cheese in the dispenser had a best by date of April 11; the dispenser was removed that day, before all patients were identified. The remaining pouch of nacho cheese sauce was laboratory confirmed to have botulinum toxin type A and toxin-producing C. botulinum. C. botulinum isolates from 3 patients clustered with the cheese isolate by WGS. Conclusion Contaminated nacho cheese sauce served at a local gas station was the source of the largest outbreak of foodborne botulism reported to date in California. No other botulism cases associated with this commercial cheese sauce were identified elsewhere in the United States; although the mechanism of contamination is unclear, the cheese was likely contaminated locally. Intensive public health investigation and intervention, before all cases were identified and C. botulinum toxin was detected in the product, likely prevented additional cases and possible deaths Disclosures All authors: No reported disclosures.