CNN
—

One person died and eight people were hospitalized after an outbreak of botulism in a restaurant in the French town of Bordeauxaccording to a press release published Wednesday by the French public health organization.

Two less serious cases were also identified, according to local health authorities.

It is believed the diners ate sardines from a stash of homemade oil, contaminated with botulism bacteria. They all dined at the Tchin Tchin wine bar from September 4 to 10, said Public Health France.

According to BFMTV, a CNN subsidiary, the deceased customer was a woman in her thirties who was passing through Bordeaux with her companion, still in intensive care.

Botulism is a paralyzing nerve toxin, considered one of the most powerful and deadly substances in the world.

It is produced by the bacteria Clostridium botulinum and sometimes by strains of Clostridium butyricum and Clostridium baratii. Rod-shaped bacteria are commonly found in soil and sediments of lakes, rivers and oceans.

The bacteria thrive in low-oxygen conditions, such as canned foods, deep wounds, and the intestinal tract, but when threatened, they form protective spores covered in a hard coating that allows them to survive for years.

Thierry Touzet, deputy director of civil protection in Gironde, told journalists on Wednesday that the restaurant would be closed “for the next few days, or even weeks” following discussions with the owner to facilitate cleaning and disinfection of the premises.

“He considered a longer closure to carry out all these operations, but also to train in food preservation techniques,” said Touzet.

“The establishment was generally well run but there was a real problem in the food preservation process,” he explained, adding that the owner was asked to no longer produce canned fish.

He added that nine pots of sardines were served during the week the infections were identified, and that around 25 people may have eaten the fish.

France’s public health agency warned anyone visiting the restaurant with symptoms of botulism to seek immediate medical attention. These symptoms may include abdominal pain, vomiting, diarrhea, blurred or double vision, and dry mouth accompanied by difficulty swallowing or even speaking.

Treatment of serious botulinum infections may involve assisted breathing in intensive care. However, prompt treatment with antitoxins after the onset of symptoms can shorten hospitalization times.

Botulism can be fatal in 5 to 10% of cases, according to Public Health France.

Bordeaux, in southwest France, is known for its history and wine. The city is popular with tourists and also hosts matches in the ongoing Rugby World Cup.

CNN has contacted the Bordeaux prosecutor and the Tchin Tchin wine bar for comment.