SWEDEN – Researchers at Livsmedelsverket, or the Swedish Food Agency in English, have created a new system for evaluating and categorizing Shiga toxin-producing Escherichia coli (STEC) strains according to the potential public health impact.
The goal of the study was to fill knowledge gaps regarding the characteristics dictating the degree to which certain subtypes of STEC can cause severe illness. Researchers used information on the percentage of severe illness-related STEC infection cases in humans to do this.
In 2019, the Joint Expert Meeting on Microbiological Risk Assessment (JEMRA) of the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO) put forth the idea of classifying a STEC strain’s pathogenic potential purely based on the presence of virulence genes.
Researchers contrasted the JERMA recommendation for categorizing STEC strains found in food with the likelihood of serious clinical outcomes following infections with the same strains for the current study.
For the comparison, the researchers collected information from the European Food Safety Authority (EFSA) on confirmed reported human STEC infections in the EU/European Economic Area (EEA) between 2012 and 2017.
The STEC serogroup cannot be utilized as a predictor of clinical outcome, according to an examination of EFSA data.
The EFSA also came to the conclusion that any STEC subtype can be linked to life-threatening illness, but strains that have the gene for Stx2a toxin production had the highest rates of hemolytic uremic syndrome (HUS).
STEC strains within classes were compared to their estimated likelihood to cause serious disease in order to assess the consistency between JEMRA’s technique and clinical data from EFSA.
Findings showed that distinct STEC variants are not categorically categorized by their capacity to induce severe disease by existing techniques.
To address the shortcomings of current techniques, the researchers created a novel strategy. The new approach is risk-based in terms of the likelihood and effects of infection, and it also increases the openness of risk management choices.
The approach does not take into account the risk of a STEC genotype being present in food because this would need genotype-specific risk assessments taking exposure into account, which would require more work and data that are not always available.