It could have been a global Salmonella outbreak with thousands of cases and “potentially many deaths”. Instead it’s the story of how a “disaster” was averted thanks to the biggest recall in the history of chocolate products, including the most famous surprise eggs ever. A race against time to prevent the disease from erupting among the youngest in Europe a few days before Easter. The ‘Ferrero case’ leads the way in the scientific community, which wanted to bring the story of the 455 cases of Salmonella typhimurium intercepted in 17 limited countries as an example of teamwork and ability to trace and intervene. The result was obtained with the collaboration of the company and the ‘intelligence’ and response activity of the health authorities, and the experts wanted to sum up the lessons learned, on the occasion of a day before the European Clinical Microbiology Congress and infectious diseases (Eccmid 2023), the event scheduled in Stockholm (Sweden) in mid-April.
Like any other manufactured food, chocolate too can become contaminated if key ingredients or processes go wrong. Johanna Takkinen, lead expert on waterborne and foodborne diseases of the ECDC, European Center for Disease Prevention and Control, reconstructed the story of the outbreak in Kinder chocolate eggs, the origin of which was traced to a chocolate factory Belgian. “If it hadn’t been for clear and coordinated action throughout Europe and beyond” EU borders, “there could have been many thousands more children sick and potentially many dead”, Takkinen reiterated.
It all begins on February 17, 2022, when the United Kingdom authorities (the Ukhsa Health Security Agency) launch a first alarm on the EpiPulse alert platform, hosted by the ECDC. Subject of the report: A group of 18 children reported to have monophasic S. typhimurium infection since January 2022. Seven were hospitalized and 5 of these had bloody diarrhea, a serious symptom. “Preliminary interviews of the first cases have pointed to Kinder chocolate products as a possible vehicle.” From there it was a crescendo: “Several countries have begun to report an increasing number of infections with strains similar to those of the epidemic in the United Kingdom,” explains Takkinen. By February 18, France had its first two cases, and by March 18, infections had risen to 59 cases in 5 countries.
At the end of March, the ECDC coordinates a teleconference with the affected countries: 4 non-human samples of S. Typhimurium, genetically close to human isolates, have been identified in a public database. Within a week, these isolates were confirmed to have come from a Belgian chocolate factory. There are 4 factories within the EU that produce this chocolate in large quantities, but now the circle is getting smaller. The new microbiological evidence allows various agencies to focus investigations on a single facility.
In the meantime, Takkinen retraces, the decision was made in the UK and Ireland to recall some products on 2 April. On April 8, the authorities ordered the closure of the chocolate factory and two days later issued a global product recall. The alert reached 130 countries. In addition to the 401 cases identified in the EU and UK combined (the UK had the highest number, 128), additional infections were identified in Switzerland (49), Canada (4) and the US (1). The ECDC and EFSA have also published rapid outbreak assessments to keep the public informed.
Children under 10 made up the majority of reported cases (86%) and approximately two-thirds (61%) were female. A number of adults (27), most aged between 21 and 40, and women (18 of 27) were also infected. Among these cases were also a small group of men and women aged between 41 and 70 years. As for the symptoms, out of 349 cases analysed, 28% were serious enough to be hospitalized. For 179 patients, information interviews were available mainly with family members: 95% had reported having consumed Kinder chocolate produced in the Belgian factory, which in the meantime was subjected to checks.
Testing of multiple products from the affected plant resulted in 81 Salmonella positive samples, with two different strains, between December 3, 2021 and January 25, 2022. Authorities estimated that the event that led to the original contamination occurred occurred before December 2021. An end product was identified as positive on December 3 and the first case with symptom progression occurred on the 12th of the same month, experts note. It takes some time for products to transition from manufacturing to retail sites, and therefore most of the first cases started to appear in January 2022.
Investigations have identified anhydrous milk fat reservoirs as contamination hot spots. This anhydrous butterfat was sourced from a factory in Italy that tested negative for Salmonella. The Belgian plant was therefore subjected to several cycles of cleaning and disinfection before being able to proceed with a conditional reopening on 17 June 2022, and then with the reissue of the permanent license for production on 17 September 2022.
“Children – concludes Takkinen – were at very high risk in this outbreak, with several chocolate products, especially chocolate eggs, affected by the contamination, all before Easter. Only through intensive collaboration and regular communication (public health – food safety) authorities were able to prevent a devastating global outbreak Crucial to preventing the outbreak from escalating was the effective early detection of cases through UK Salmonella surveillance and verification timely response of a rapidly evolving multinational epidemic thanks to timely country responses”.