Multi-country outbreak of monophasic Salmonella Typhimurium sequence type 34 linked to chocolate products – first update
On 17 February 2022, the United Kingdom (UK) reported a cluster of cases with monophasic Salmonella Typhimurium sequence type 34 infection. As of 18 May 2022, 324 cases had been reported in 12 EU/EEA countries and the UK, including two distinct strains.
Most cases are below ten years of age and 41% of all cases have been hospitalised. The two strains are multidrug-resistant and some tested isolates also carry resistance to disinfectants that are based on quaternary ammonium compounds and hydrogen peroxide, but remain susceptible to azithromycin, ciprofloxacin, meropenem, and third generation cephalosporins. Epidemiological investigations suggested specific chocolate products of Brand A, produced by Company A in Processing Plant B in Belgium, as likely vehicles of infection.
Two strains of monophasic Salmonella Typhimurium matching the outbreak strains were identified in the anhydrous milk fat (AMF) line at Plant B between December 2021 and January 2022. The AMF was provided by an Italian supplier where Salmonella was not detected. This supplier delivered the AMF to other plants of Company A where, based on the available evidence, Salmonella was not detected.
On 8 April 2022, based on official controls, the food safety authority in Belgium decided to withdraw the authorisation for production of the Plant B due to lack of transparency and insufficient guarantees for safe production. Company A globally recalled all products of Brand A produced at Plant B. Public warnings were issued by the competent national authorities in different countries.
This outbreak has evolved rapidly, with children most at risk for severe infection. The closure of Plant B and the global recall of all their products have reduced the risk of exposure. However, eight cases cannot be explained by consumption of chocolate products such as those manufactured at Plant B, suggesting that there may also be other sources of infection.