An Outbreak of Foodborne Botulism Caused by Clostridium botulinum BoNT/A3 in Pickled Eggs - Weihai City, Shandong Province, China, July 2024.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Foodborne botulism is caused by botulinum neurotoxin (BoNT). Clostridium botulinum (C. botulinum) is a strictly anaerobic, Gram-positive bacterium, which is a key pathogen capable of producing BoNT. BoNTs can be classified into seven serotypes (A to G) based on their antigenic properties. Among these, BoNT/A is one of the most common serotypes.

WHAT IS ADDED BY THIS REPORT?: This was a case of foodborne botulism in Weihai caused by homemade pickled eggs contaminated with C. botulinum. Five individuals presented with symptoms, while three were asymptomatic. All patients received botulinum antitoxin treatment, and no deaths occurred. During this outbreak, 12 isolates of C. botulinum were obtained. The phylogenetic analysis results revealed that all the isolates came from the same origin.

WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: This outbreak indicated that foodborne botulism remains a public health issue in China. We need to strengthen publicity and education efforts to inform people of the potential risk of botulism associated with consuming homemade traditional pickled foods. Heating and boiling homemade foods thoroughly can destroy toxins and prevent foodborne botulism.