Epidemiological and etiological characteristics of cluster infections associated with Escherichia albertii in a middle school in Hangzhou city, Zhejiang province, 2023

Objective To understand the epidemiological and etiological characteristics of cluster infections occurred in a school in Hangzhou, Zhejiang, in February 2023.

Methods  Epidemiological survey was carried out. Anal swabs from diarrhea patients, food and environmental samples were collected to screen and isolate pathogens. Antimicrobial susceptibility test and whole genome sequencing analysis were performed for isolates.

Results Twenty-two patients were identified in this outbreak. The clinical manifestations of these patients included diarrhea, abdominal pain, vomiting and other gastrointestinal symptoms. The eae-positive isolates were identified from six anal swabs, which were confirmed to be Escherichia albertii. Six E. albertii isolates were susceptible to all 26 antimicrobials tested. Phylogenetic tree based on core genome Multilocus sequence typing, six E. albertii isolates formed a single cluster, and the difference of single nucleotide polymorphism in the core genome was 0 to 1 bp each other.

Conclusion This cluster infections were associated with E. alberii. It was the first report of diarrhea outbreak caused by E. albertii in China.