After the frankfurters, chocolate pancakes, gorgonzola, salmon sandwiches, the alert for the possible presence of listeria moves to cooked ham, while a batch of fontina was withdrawn due to E.coli risk. 

Why has the number of reports been growing in recent years?

And why does it concern such a diverse food group?  

"

The growth of alerts

- explains

Pier Sandro Cocconcelli

, professor of Food Microbiology at the Catholic University of the Sacred Heart -

is not a sign of greater danger than in the past

, but of

greater attention to food safety

. Today, compared to 10 o 15 years ago, there are more controls and more information to the consumer. We have

a transparent national and European alert system

, which serves

to prevent risks

, not only for listeria but also for other pathogens, such as Escherichia coli ", as documented by the data collected by

Rasff,

the

European Union Rapid Alert System

The risks for frail people

Listeria

monocytogenes

is a bacterium that

can contaminate the raw materials

used for food production and cause

serious consequences

, including death, in frail or immunocompromised people and pregnant women.

In particular, a very dangerous strain has recently been found in some batches of food withdrawn from the market.

Contamination by listeria and production processes

"

Listeria monocytogenes manages to persist in fresh food production and packaging plants

: it can form biofilm on the steel blades of the slicers or on the surfaces, which thus become a means of cross contamination. Furthermore, - explains Cocconcelli - this reproduces well at low temperatures. temperatures used for the preservation of foods that can be used as reservoirs, such as fresh cheeses and cured meats, processed meat, smoked fish ". 

Since these products last on the shelves for a long time,

the bacterium uses these weeks to proliferate

, surpassing the safe level (100 cells per gram).

The number of batches withdrawn, however, underlines the expert, "are not indicative of the fact that the problem is increasing but of the fact that there is a lot of attention from producers and preventive controls are working. 

Consumer advice

Consumers also need to pay close attention to their food safety.

The indications remain those disseminated by the Ministry of Health: cooking food when indicated on the labels, hygiene in the kitchen and in the fridge;

do not store cooked foods for a long time and, before eating them, heat them to high temperatures, always making sure to keep them in closed and separate containers. 

Future prospects

Scientific research could bring extra help.

"It is possible - concludes Cocconcelli - that in the future new strategies for the control of harmful microorganisms will be implemented, for example through the use of bacteriophage viruses, which have the ability to inactivate bacteria, reducing the risk in the environments".