11 hours Ago By Joe Whitworth
Scientists have described the investigations performed and control measures taken in relation to a multi-country Salmonella outbreak traced to Ferrero chocolate in 2022. In February 2022, the United Kingdom detected a monophasic Salmonella Typhimurium cluster of patients based on whole genome sequencing (WGS). Several other countries reported cases in the cluster.
Epidemiological, microbiological, and traceability investigations pointed toward Ferrero in Belgium. A total of 456 cases, belonging to two genetically different WGS clusters, in 14 countries of the European Union, the UK, Switzerland, Canada and the United States were linked to the outbreak, between December 2021 and June 2022. In total, 128 people were sick in the UK and 121 in France.
The U.S. and Canada had one case each.
Almost 90 percent of the patients were younger than 10 years old. Overall, 61 percent were females and the hospitalization rate was 38 percent. A total of 211 people reported consumption of various types of Kinder chocolate produced by Ferrero in the seven days prior to disease onset.
Chocolate eggs, marketed for children, were consumed by 168 patients. Likely contamination before December According to a study published in BMC Infectious Diseases , the long shelf life of 225 to 270 days for implicated products increased the risk of a prolonged and widespread outbreak. Investigations by the Belgian food agency revealed routine samples of raw materials, intermediate, semi-finished and finished products as well as environmental and rinse oil samples taken by the company between December 2021 and January 2022 were positive for Salmonella.
Nine isolates matched with human isolates from both WGS clusters. Authorization for production was temporarily withdrawn in April 2022 and products were recalled from more than 110 countries, followed by a decrease in patients. Chocolate is a low-moisture food, in which Salmonella can persist for extended periods.
The high fat content of chocolate products potentially increases the thermal resistance of Salmonella and provides protection against acidic conditions in the stomach. In mid-February 2022, an alert was submitted by the UK via EpiPulse, a platform hosted by the European Centre for Disease Prevention and Control (ECDC). A notification was published on the Rapid Alert System for Food and Feed (RASFF) and via the Early Warning and Response System (EWRS) by the European Commission on March 25 to alert food safety and public health authorities.
The first reported date of onset was Dec. 12, 2021, in the UK. The peak number of cases occurred in early April 2022 and the last case was on June 16, 2022.
Considering the average time from production to retail is 60 days, patients in December 2021 and early January 2022 cannot be explained by positive samples from December 2021. The two months of storage before distribution suggests contamination in the plant before December 2021, said scientists. Multiple positive samples Belgian investigations found that 81 samples taken by Ferrero between Dec.
3, 2021, and Jan. 25, 2022, had tested positive for Salmonella. According to Ferrero’s risk analysis, all possibly contaminated batches had been destroyed between December 2021 and January 2022.
The company concluded there was no risk to the public so Belgian authorities were not informed. Scientists said positive findings via the self-check system after internal measures were taken indicated actions were not adequate to eliminate contamination. “The magnitude of the outbreak underlines the importance of timely and open communication of food businesses to food safety authorities in case of Salmonella detection,” said scientists.
Four isolates in cluster 1 were from an environmental swab in the preparation area, an intermediate and a finished product. Five isolates in cluster 2 came from an intermediate product as well as from the anhydrous milk fat (AMF) circuit (filter, residual material from the equipment, and spout). Because several samples from the AMF circuit tested positive, this system was the likely point of contamination.
The AMF was provided to the Belgian plant by an Italian supplier. Italian authorities investigated the supplier in April 2022 but Salmonella was not detected. Following detection of Salmonella in self-check samples at the plant on Dec.
15, 2021, mitigation measures taken by Ferrero included discarding affected batches, cleaning and temporarily closing the implicated production lines as more samples tested positive. Lines were restarted following deep cleaning, obtaining negative samples and bypassing of the AMF tank. After extensive cleaning, investments in new equipment and a review of the hazard analysis and critical control point (HACCP) system, the plant received permission to restart production in June 2022.
Final authorization was given in September 2022. (To sign up for a free subscription to Food Safety News, click here ).
