In 2023, a bacterium closely related to E. coli caused a significant outbreak in China. This event marked the first reported case of gastroenteritis attributed to E. albertii outside of Japan. The bacterium, Escherichia albertii, is known to cause watery diarrhea, abdominal pain, and fever, with most cases resolving without complications. However, the probable contaminated food source remains unidentified, which poses a challenge for public health officials.

Unraveling the Mystery of the 2023 E. albertii Outbreak

Outbreak Details

In February 2023, an outbreak was reported in a junior high school in Hangzhou, Zhejiang province. Out of 770 students, 22 were defined as suspected cases. The incubation period for infection ranged from 24 to 43 hours. All 770 students were in the third grade and had the same dinner on one day from a catering delivery company. Unfortunately, no food samples were kept for analysis, making it difficult to determine the exact source of contamination.Classes were suspended, and students were sent home. Only those showing severe symptoms were enrolled in the study. Sixteen environment smears, including samples from desk surfaces, refrigerator interiors, and water dispenser outlets, and 12 food samples from other days in February were taken. Meals for second- and third-year students were delivered by two different food companies, but only the third-grade students were affected.

Isolation and Analysis

Escherichia albertii strains were isolated from anal swabs collected from six patients. Each isolate was classified as sequence type ST2686. To assess the relationships among outbreak strains and other E. albertii strains, scientists retrieved 43 E. albertii genomes from the NCBI database and all available epidemiological information. The 43 strains were isolated from different sources in 13 countries between 1983 and 2022, including three ST2686 strains and six strains associated with previous outbreaks.The six isolates from this study coalesced into a single, highly genetically related cluster, suggesting a common origin. These isolates were different from strains associated with six outbreaks in Japan. This indicates that no known or dominant E. albertii types are predictive for outbreaks, and strains from multiple sources can potentially cause illness.

Public Health Implications

The identification of an E. albertii outbreak in China highlights the importance of continuous surveillance and monitoring of foodborne diseases. Even though the contaminated food source was not identified in this case, the isolation and analysis of the bacteria provide valuable information for future research and prevention efforts. Public health officials need to remain vigilant and take appropriate measures to prevent the spread of such outbreaks.It is crucial to improve food safety practices and ensure the proper handling and storage of food. Regular testing and analysis of food samples can help detect potential contaminants and take timely action to prevent outbreaks. Additionally, education and awareness campaigns can help consumers make informed choices and reduce the risk of foodborne illnesses.In conclusion, the 2023 E. albertii outbreak in China serves as a reminder of the need for a comprehensive approach to food safety. By working together, researchers, public health officials, and the food industry can better understand and prevent such outbreaks in the future.