Foodborne outbreaks associated with bacterial toxins in Spain, 2015-2023

Abstract

Introduction: Foodborne outbreaks caused by bacterial toxins are a frequent cause of intoxication. Although these outbreaks are usually self-limiting, they may lead to hospitalizations and deaths, and their investigation is key to establish preventive measures. This study assesses, for the first time at the national level, the bacterial toxin-related outbreaks impact reported to the Spanish National Surveillance Network (RENAVE).

Method: A descriptive study was conducted on foodborne outbreaks associated with B. cereus, C. perfringens and S. aureus reported to RENAVE between 2015 and 2023.

Results: A total of 380 outbreaks resulting in 8853 cases were reported. Annually, there were between 13 (2020, coinciding with the COVID-19 pandemic) and 67 (2023) outbreaks. 63 hospitalizations (0.71%) and 7 deaths were recorded. S. aureus was the most frequent agent (176 outbreaks) and was associated with the highest hospitalisation rate (1.88%), whereas C. perfringens caused the largest outbreaks (mean: 41.4 cases) and the highest number of cases (5,428). Outbreaks due to S. aureus occurred more frequently in summer, those caused by B. cereus increased in spring and C. perfringens outbreaks declined during holiday periods. The most frequently associated foods were meat and meat products, and the most common setting was food service establishments.

Discussion: The COVID-19 pandemic led to a decrease in the reporting of these outbreaks, but it has subsequently increased. The characteristics of these outbreaks were similar to those described internationally, although they were larger in Spain. Conducting targeted epidemiological studies to better characterize these outbreaks would support the implementation of the most appropriate control measures.