A number of rugby fans visited Bordeaux, France, in September of 2023 for the Rugby World Cup and reported  eating home-canned sardines in the same bar and restaurant

The University of Minnesota  Center for Infectious Disease Research and Policy (CIDRAP) reports that 15 cases of botulism poisoning resulted, including one death.

CIDRAP’s summary of the botulism outbreak follows:

The report presented the clinical case descriptions of eight patients seen at the Bordeaux University Hospital, where the first patient treated in the outbreak was admitted to the intensive care unit (ICU) on Sept. 6.

Home-canned sardines were implicated.

All three initial patients seen at the hospital reported visiting France for the rugby tournament. On Sept. 10, French investigators questioned the three, who all reported eating home-canned sardines in the same bar and restaurant in Bordeaux.

On Sept. 11 and Sept. 12, the hospital saw five more patients, all international visitors, for symptoms of botulism poisoning, including descending paralysis and extensive gastrointestinal illness.

The patients came from Canada, France, Ireland, and the United States. Two patients were men, six were women, and only one was younger than 50. The average time between the consumption of sardines and the first signs of illness was 13 hours.

“Six of eight cases required invasive mechanical ventilation because of respiratory muscle paralysis,” the CIDRAP authors said. The median delay between the onset of symptoms and intubation was 25 hours.

Though rare, botulism can be one of the most severe foodborne illnesses, often caused by inadequately processed home-canned, preserved, or fermented foods.

From 2008 to 2018, France reported 82 outbreaks of food-borne botulism, including 159 cases, and the most people involved in a single outbreak was six, making the new outbreak the nation’s largest.

Clinicians across France have been cautioned to look for symptoms of botulism in patients who have recently traveled to Bordeaux. Such symptoms include difficulty swallowing, blurry vision, slurred speech, and descending flaccid paralysis.

“Food-borne botulism can be misdiagnosed,” the authors conclude. “This report highlights the importance of promptly notifying cases with suspected botulism, as this triggers awareness and immediate investigation to determine the source and control the outbreak.”