Health. Listeriosis: How to identify the symptoms of this foodborne illness?

21 cases of listeriosis identified, including 18 cases since the beginning of June.

According to a press release from the government and Public Health France released late Tuesday, August 12, health authorities were able to establish a possible link between these cases of listeriosis, which resulted in the death of two people, and the consumption of pasteurized milk cheeses produced by the Chavegrand company (Creuse).

All batches of cheese produced before June 23, 2025 are subject to a mass recall.

What products are being recalled?

These are all soft cheeses with a bloomy rind made from pasteurized cow's milk (such as Camemberts or creamy cheeses) or goat's milk (such as logs), which were marketed until August 9, 2025 by the cheese dairy throughout the national territory as well as internationally, under different commercial brands.

People who have consumed it and who have a fever, whether isolated or accompanied by headaches and body aches, are invited to consult their doctor and inform them of this consumption.

What is listeriosis?

Listeriosis is a rare but potentially fatal foodborne infection caused by the bacteria Listeria monocytogenes . First isolated in France in 1918, it was described as a new bacterial species in 1926, reports the Pasteur Institute.

In 1982, it was identified as foodborne. It is therefore recognized as a biological hazard in the food industry. Listeriosis is a notifiable infection, which allows for its national surveillance.

The bacteria Listeria monocytogenes has the ability to multiply at low temperatures in the presence of high salt concentrations.

Ubiquitous, the bacteria is found in water, soil, rotting plants and in many animals.

" L. monocytogenes has the capacity to contaminate ready-to-eat foods and food manufacturing sites,” specifies the Pasteur Institute.

Can you recognize contaminated food?

The bacteria is sensitive to heat but can multiply slowly in refrigerators. Lysteria monocytogenes does not alter the taste of food, unlike other bacteria, which makes it difficult to identify.

"In France, the foods most frequently contaminated by Listeria monocytogenes are dairy products (especially soft cheeses and raw milk), charcuterie (tongue, pâté, rillettes), smoked fish, certain vegetables, and raw or undercooked meat,” underlines the Pasteur Institute.

Transmitted by the ingestion of contaminated food, the digestive form of listeriosis, after an incubation period of a few hours to a few days, manifests itself by:

• abdominal pain;
• diarrhea,
• sometimes accompanied by flu-like symptoms.

Invasive forms, characterized by the spread of bacteria outside the digestive tract, result in:

• sepsis (blood infection);
• meningoencephalitis (infection of the central nervous system): headache, fever, nausea, vomiting, sometimes behavioral disorders;
• or maternal-neonatal infection.

In these severe forms, the incubation lasts from a few days to 1 to 2 months.

Who is at risk?

The invasive form of the disease mainly affects the elderly, immunocompromised, pregnant women and newborns.

What are the specific risks for pregnant women?

In pregnant women, transmission occurs from mother to fetus via the placenta. It can be asymptomatic in the mother or result in fever, contractions, and sometimes premature delivery. According to Public Health France,

• if infected during the first half of pregnancy, it can cause spontaneous abortion;
• If infected between the 6th and 9th month of pregnancy, listeriosis can lead to premature delivery and sometimes fetal death. in utero;
• In case of late infection during pregnancy, the mother may not show any symptoms and listeriosis may only manifest as signs of infection in the newborn.

After detection of the bacteria from a normally sterile site, treatment consists of the administration of antibiotics.

What are the numbers?

Each year in France, between 300 and 400 cases of invasive listeriosis are reported. The incidence is 5.6 cases per million inhabitants, making it the second leading cause of foodborne mortality.

How to prevent listeriosis?

Prevention in people at risk consists of:

• avoid the consumption of unpasteurized or UHT dairy products including raw milk cheese, cold cuts, raw or undercooked meat, smoked fish, raw shellfish, surimi, tarama, peppers, parsley and raw sprouted seeds.
• remove the rind from all cheeses;
• cook animal foods thoroughly;
• wash vegetables and herbs thoroughly;
• Cook ready-to-eat products thoroughly until boiling.

"To avoid cross-contamination (from one food to another), raw and cooked foods should be stored separately. Pre-packaged products are preferable to products purchased by the cut, the latter of which should be consumed quickly after purchase," adds the Pasteur Institute.