The researchers found that over a 10-year period in France, sporadic HUS cases of E. coli O26 and E. coli O80 have trended significantly upward, while E. coli O157 has markedly decreased.
Escherichia coli-associated hemolytic uremic syndrome (HUS) is a major public health risk in France, according to scientists. HUS is a serious complication associated with E. coli infection that can lead to kidney failure, brain damage, and other lifelong complications.
Researchers conducted a study of 1,255 pediatric sporadic cases reported from 2012 to 2021, and the results were published in the journal. emerging infectious diseases.
The annual number of reported cases ranged from 109 in 2014-2015 to 163 in 2017. Most of them were children under 3 years old. E. coli serotypes O26, O80, and O157 accounted for 78% of cases, and 13 significant clusters were identified.
sporadic cases have been recorded
In France, surveillance of Shiga toxin-producing Escherichia coli (STEC) is carried out through voluntary clinical and microbiological surveillance of HUS in children under 15 years of age. The annual incidence of pediatric STEC-HUS is relatively high. A suspected case of STEC-HUS in her under 15 years of age has been reported to Santé Publique France, the French public health agency.
Microbiological STEC surveillance is voluntary and coordinated by the Center National Reference Center (CNR) for Escherichia coli, Salmonella enterica and Trichophyton rubrum at the Institut Pasteur and its affiliated laboratories.
Identifying the source of contamination in sporadic cases is difficult, scientists say, for reasons including limited epidemiological data, multiple potential sources of contamination, and gaps in knowledge about pathogen source and route interactions. Ta.
1,132 samples were sent to CNR, and STEC serogroups were identified in 717. The top three serogroups accounted for 559 of the 717 cases, with O26 in 228 cases, O80 in 149 cases, and O157 in 182 cases.
The proportion of female and male patients was comparable throughout the study period. Almost 800 of the 1,255 cases were in patients under 3 years of age. Incidence varied by age group and was most common in children 1 to 2 years of age. The highest incidence was from July to October.
In STEC O26 and STEC O80, incidence was slightly higher in the eastern half of France. For STEC O157, the highest rates were mainly in northwest France.
cluster found
Serogroup-specific scanning identified two significant clusters: STEC O26, which occurred in southeastern France in 2019, and STEC O80, which occurred in northeastern France in 2017. His WGS data of isolates within the 2019 O26 cluster identified three His WGS-related clusters of two isolates each. However, epidemiological investigations did not identify a common source of infection.
Southeastern France is the second most densely populated region in the country and includes the metropolis of Lyon, as well as rural areas and areas with high cattle densities.
The annual scan identified 13 significant clusters. With the exception of 2014 and 2017, there has been at least one cluster each year, with up to three in 2018. Median cluster size was 10 cases, but ranged from 2 to 20 cases. The clusters occurred from June to November, and most of them coincided with the July to October seasonal peak seen in STEC-HUS notifications.
“The results of this study have many implications for the detection and investigation of outbreaks in STEC-HUS in France, as well as for research perspectives to improve knowledge of environmental risk factors associated with geographic disparities,” the researchers said. said.
“Taking geographical differences into account is relevant for the analysis of surveillance data for the purpose of outbreak detection, especially for assessing epidemiological signals and deciding to initiate investigations. We plan to use the results in further studies to investigate possible associations with environmental parameters.”
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