After five people were hospitalized in intensive care, the authorities pointed to a wild garlic pesto sold in jars. But contaminations following the consumption of industrial products remain relatively rare.
Five people in intensive care and 600 jars of wild garlic pesto actively sought. Health authorities suspect these artisanal preserves, sold at fairs in Indre-et-Loire since the beginning of spring, of being the source of the contamination of many patients by botulinum toxin. This, produced by a bacterium that develops in poorly preserved food, causes botulism, a serious neurological disease that can be fatal in some cases.
Botulism remains a very rare disease, however. There are around twenty outbreaks of contamination per year on average in France, health authorities point out. Foodborne botulism (one form of this disease) is not transmitted between humans, but only by the ingestion of contaminated food, the Pasteur Institute points out. So what risk do we run by consuming canned or jarred food?
Mainly family or artisanal preserves called into question
Food contamination by spores occurs first in their environment, recalls Anses in its fact sheet on botulism. “The conditions of preparation and storage of foodstuffs then determine possible germination of spores, the growth of bacteria as well as toxinogenesis” – the production of toxins. Low-acid preserved foods are the most at risk, especially in the case of “failure to control the canning process”that is to say, all the measures which aim to sterilize the preserve, from the cooking temperature to the pH, including the closing of the preserves.
“The foods most often involved in botulism outbreaks are canned goods and home-made or artisanal products.”recalls Anses. Ham, pheasant pâté… Most of the cases of food botulism traced between 2013 and 2016 followed the consumption of meat, details Public Health France in a study published in 2017. There are also a few cases of “home-prepared canned vegetables”such as green beans, asparagus… In 2023, the contamination of 16 customers of a Bordeaux restaurant – which resulted in one death – came from canned artisanal sardines.
A complex process to follow
But contaminations following the consumption of industrial products remain relatively rare. For canned goods, respecting the canning process is the best way to protect against botulism. An industrial process, more stable and reliable than artisanal production, necessarily reduces the risk. As for charcuterie, nitrite salt, controversial for its harmful effects on health but widely used by manufacturers, is according to ANSES “the most effective C. botulinum growth inhibitor”.
There is, however, no routine control during production because “The search for the toxin can only be carried out under special security conditions”underlines Anses. The risk is reduced, but it still exists, which explains why a few cases of food botulism following the consumption of industrial products have been noted in the past. Anses mentions nine outbreaks in which industrial products were involved between 2008 and 2015. This last year, for example, the problem came from a Bolognese sauce served in a restaurant, prepared with contaminated frozen minced meat.
Whether you are a craftsman or an industrialist, you must above all “Comply with regulations and good health and technical practices,” summarizes the Federation of Preserved Food Industries (Fiac). Before manufacturing and placing canned food on the market, it is essential to be trained or supported to master the canning process and guarantee safe products for consumers.” The Fiac recalls in particular that we must ensure that “compliance with good hygiene practices”at the“packaging sealing” and to “the application of a heat treatment scale” to destroy or inhibit potential bacteria or enzymes.
To limit the risks during consumption, you must be very careful when opening a can or jar, warns Anses. “Cans that are deformed or bulging, or those that give off a suspicious odor when opened, should not be consumed. When opening glass jars, the noise caused by the entry of air should be heard.” In the event of contamination, you must be aware of the symptoms in order to receive rapid treatment: botulism causes eye problems (double vision), difficulty swallowing and, in advanced forms, paralysis of the muscles, particularly respiratory muscles.
