Botulism: four questions to understand the neurological condition that affected a dozen people

In Bordeaux, Barcelona and Ile-de-France, at least twelve cases of botulism have been detected in recent days

Botulism: four questions to understand the neurological condition that affected a dozen people

In Bordeaux, Barcelona and Ile-de-France, at least twelve cases of botulism have been detected in recent days. A 32-year-old person died on Tuesday, September 12, in the Paris region, as a result of the disease. In the city of Gironde, eight people were placed in intensive care or in a continuous monitoring unit. In the Catalan capital the patient was taken care of by medical services.

All infected people ate homemade canned sardines served in a Bordeaux restaurant, the Tchin Tchin Wine Bar, which was not authorized to sell them. Its fish is suspected of being the cause of the disease. “There is little doubt about the causal links between canned foods and the appearance of symptoms,” according to Thierry Touzet, deputy director of the Departmental Directorate for Population Protection of Gironde. Rare, but potentially fatal, Le Monde answers four questions about the disease.

Botulism is a rare neurological condition. According to data from Public Health France (SPF), dating from 2017, the national incidence rate is low, amounting to 0.08 per million inhabitants. The disease can be serious when not treated in time, in 5% to 10% of cases it is fatal, according to the World Health Organization (WHO).

The condition is caused by a toxin, which acts on the nervous system, produced by the bacteria Clostridium botulinum, explains the national public health agency. Seven types of botulism exist, classified by letter from A to G. Up to five of them can affect the human species: A, B, E, F more rarely according to the Pasteur Institute, and C, also , according to SPF.

Three forms of botulism are known. It can be caused by colonization of the intestine in the presence of bacterial germs, which is particularly the case with infant botulism, or by contamination of a wound, particularly during intravenous drug consumption.

The most common form of illness remains food poisoning through ingestion of “the toxin in preserved foods that have not undergone an extensive sterilization process,” explains the Pasteur Institute. The foodstuffs often implicated are cured meats, cold meats or even canned goods of family, artisanal or mass distribution origin. The disease is not contagious.

The time that elapses between the introduction of the bacteria into the body and the first symptoms can range from a few hours to a few days, depending on the method of contamination. SPF estimates this to be a minimum of two hours and a maximum of eight days.

The declaration of the condition is manifested by "ocular damage (failure to accommodate, blurred vision), dryness of the mouth accompanied by a deficiency in swallowing or even speech, then paresis (decrease in strength muscular) to paralysis of the muscles", specifies the Pasteur Institute. The disease can also cause digestive problems: diarrhea, abdominal pain, nausea or even vomiting.

In the most serious cases, Benjamin Clouzeau, doctor in medical intensive care at the Bordeaux University Hospital, explained during a press conference on Wednesday morning that the condition can go so far as to cause respiratory paralysis. The severity of symptoms varies and may depend on the amount of toxin ingested.

One of the risks is respiratory paralysis, requiring intensive care, which is life-threatening, “types A and E being responsible for the most serious forms,” writes the national public health agency. The disease is fatal in 5% to 10% of cases, according to the Pasteur Institute, specifying that “the vast majority of patients treated without delay recover without after-effects, but the duration of treatment and convalescence can last several months” .

Dr Clouzeau adds that “the more time we spend in intensive care”, the more the recovery time can be extended, “rehabilitation too”.

There is an antidote that can be given to patients who present early, before paralysis of the respiratory muscles. The antitoxin consists of reducing the intensity of symptoms. The Pasteur Institute adds that “there is also an anti-botulinum vaccine, but it is reserved for exposed people, working in laboratories for example.”

The prevention of botulism through food poisoning is based on hygiene rules to be followed when preparing canned goods. In the event of a manufacturing defect, signs such as a bad smell when opening a can can alert you.