Eurosurveillance
An unprecedented outbreak of 15 cases (including one death) of foodborne botulism occurred in Bordeaux, France, in September 2023 during the Rugby World Cup. Here we describe the national and international outbreak investigation using credit card data and control measures taken.
On 10 September 2023, the Bordeaux University Hospital reported three suspected cases of botulism to the local public health authorities [1]. All suspected cases had visited the same restaurant (Restaurant A) in Bordeaux on different dates and reported consumption of canned marinated sardines. The sardines were part of a batch made by Restaurant A on 1 September 2023 and served between 1 and 10 September. Cases were of different nationalities. In the previous days, the city had hosted two international rugby games as part of the Rugby World Cup attended by a large number of international visitors. An investigation was initiated to identify and contact persons visiting restaurant A and to contact public health agencies of countries whose citizens were affected by the outbreak.
Considering the severity of botulism and the urgency of control measures to stop the outbreak, an active search for persons who had consumed the sardines was performed by using data retrieved from credit card receipts of restaurant A.
A suspected case of botulism was defined as a person with symptoms compatible with botulism (oculomotor palsy, mydriasis, ptosis, dysphagia, nausea, vomiting, diarrhoea), living or visiting the Bordeaux area and visiting Restaurant A between 1 and 10 September 2023. A confirmed case was defined as detection of type B botulinum neurotoxins (BoNT) in stool and/or serum samples and/or detection of type B C. botulinum in stools from a suspected case.
By screening meal orders and credit card receipts of Restaurant A, we identified 29 customers who had ordered canned sardines (Figure 1). Among these, 12 had already been identified as suspected cases, 14 were contacted by the French or British health authorities and were considered non-cases as they did not present any symptoms and three were symptomatic British citizens who were urgently referred to an emergency care in the United Kingdom (UK) on 13 September where they received botulinum antitoxin.