Five people have been taken to hospital and put on ventilators with suspected botulism linked to pesto.
The French ministry of farming on Tuesday said it detected five likely cases of food-borne botulism linked to contaminated pesto sauce that had been sold at some regional market fairs in central France.
According to French media, the five people had enjoyed a birthday meal together before they fell ill. Two couples were taken to hospital on Saturday and another person on Sunday.
They received emergency treatment and were conscious but on ventilators, the prefect of the Indre-et-Loire, a department in west-central France, said.
Authorities are trying to track down around 600 containers of the pesto before they are consumed, prefect Patrice Latron said.
“People who bought the same sauce must throw it out; destroy it,” he added.
The ministry of farming called on people who may have eaten the wild garlic pesto to be “very vigilant”.
“Considering the incubation time (from a few hours to a few days) and the serious nature of the disease, people who have consumed these products are called to be very vigilant and to consult a doctor in case of symptoms,” the ministry said.
Botulism is a rare but potentially fatal disease if not diagnosed rapidly and treated with antitoxin, according to the World Health Organization (WHO).
It comes from a bacteria, which, along with its spores, can live in soil and can be found on the surface of fruits, vegetables, and herbs.
The bacteria can make potent neurotoxins which cause botulism. Food-borne botulism primarily is caused by the consumption of improperly processed food which has been contaminated.
The French government issued an immediate recall of the cooking paste, which was made by a small local producer.
Some samples have been sent to the biomedical research centre, the Institut Pasteur, for further analysis.
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It usually takes 12 to 36 hours for the symptoms of botulism to show.
Symptoms often begin with blurred vision and difficulty in swallowing and speaking, but sometimes diarrhoea and vomiting can also occur.
The disease can lead to problems with vision and paralysis – and can also be fatal in 5% to 10% of cases.
According to the Advisory Committee on the Microbiological Safety of Food, the UK has an extremely low number of outbreaks of foodborne botulism, with only 10 reported outbreaks involving 13 cases since 1992 – eight of which involved foods produced or illness acquired abroad.
Last year, the UK Health Security Agency warned of a botulism outbreak traced to home-prepared sardines served at a restaurant in Bordeaux, France, which resulted in three people being treated on their return to England.