Listeriosis is serious infection that usually occurs after entering food contaminated with the bacterium Listeria monocytogenes.

Although it can manifest as severe, fortunately it is a relatively rare infection observed in humans. Commonly registered in certain categories of the population etc. risk populations, which include older people, especially those over 65 years of age, pregnant women and their developing fruit and infants, immunocompromised individuals (people with weakened immunity for various reasons).

The annual rate of registration of this disease in many countries of the European Union ranges from 2-10 cases reported 1,000,000 residents (0.3 / 100,000), associated with a high mortality rate (30%

more at risk populations) and a high percentage of hospitalization (91%).

In 2006 listeriosis was 5th most common zoonotic infections recorded in Europe after Campylobacter, Salmonella, Yersinia, and VTEC-infections.

From 2006-2010 the rate of reported confirmed cases of listeria in the EU, maintained approximately the same (incidence 0.33 to 0.38 / 100,000). In 2012, the number of reported confirmed cases of listeriosis in the EU member states recorded an increase of 10.5% compared to 2011.

In the United States, this bacterium is responsible for about 1600 cases of illness and 260 deaths a year (an incidence of 0.28 / 100,000) and is the third leading cause of death in bacterial infections that are transmitted through food, with a mortality rate that exceeds even Salmonella and Clostridium botulinum.

High morbidity and mortality of this infection, and the high rate of hospitalization of patients contribute to the understanding of the disease and the importance of getting priority on improving supervision.

Triggers the infection

Bacteria of the genus Listeria are conditionally anaerobic bacteria, which means they are able to survive in the presence or absence of oxygen. Listeriamonocytogenes, the most common cause of human illness from this genus is gram-positive bacterium, named after the inventor, Joseph Lister.

Grows at temperatures in the range of 1 to 44˚C, with optimum growth temperature of 30-37˚C. Relatively quickly multiplies the 7-10˚C. Growing up in various food products and environments, is relatively resistant to freezing, drying, salt (> 10%), and ph 5,0 and more. Sensitive to temperature pasteurization (15 min. 71,7˚C or a 30 min. The 62,8˚C), and are thought to pasteurized products do not contain listeria.

The bacteria tolerate low temperatures and salt, it can survive in processed, canned foods and foods that are kept in the refrigerator.

Listeria monocytogenes is also tolerant of acid, which is essential for survival in the abdominal acid. Tolerance to acid due to the presence of the enzyme glutamate decarboxylase system.

Infectious dose of this pathogen varies among different hosts, people with compromised immunity and chronic diseases are most susceptible to infection. Although there is no study that provides exact information on infectious dose, based on epidemiological data, it is estimated that the infectious dose for immunocompromised individuals is in the range of 100-1000 bacteria. In healthy people, where the disease is manifested in less severe, infectious dose necessary for the occurrence of infection was 108 – 1010 bacteria.


Listeriosis can cause a range of different symptoms. Some patients may have no symptoms – mostly healthy people.

Previously healthy persons as well as women who are pregnant often go with symptoms of acute intestinal infection – inflammation of the stomach and intestines (nausea, abdominal pain and diarrhea, drowsiness, headache, fever).

Also, you can contact fatigue, muscle aches, joint pain, vomiting and sore throat (flu-like symptoms).


Infection with Listeria can cause serious illness, most commonly in those with chronic health conditions, the elderly or people with compromised immunity.

Serious symptoms and conditions may include: sepsis, inflammation of the brain and brain membranes, inflammation of the lining of the heart, abscesses, infected or inflamed joints. Kaj infected pregnant women, the clinical picture can be presented only as a mild illness, but can cause miscarriage, premature birth or stillbirth. In infants, can also be symptoms of severe illness, such as. meningitis, meningoencephalitis, which can lead to death.

How is it spread

The bacteria that causes listeriosis is widespread in the environment and can be found in soil, surface water, vegetation and a number of wild and domestic animals. From farm animals, listeriosis is most common in sheep, goats, cattle and others. cattle, but is found in rodents, dogs, cats, pigs, poultry, parrots and kanarinci.Golem number of domestic and wild animals – mammals, birds, fish and crabs then can carry the bacteria, but have no simptomi.Domashnite animals usually get sick through contaminated food – contaminated by rodents and wild animals, additionally badly fermented in silos.

Most people suffer through consumption of contaminated food, but may transfer the bacteria through direct contact, and inhalation. The most commonly incriminated foods that are associated with the spread of listeriosis are considered: meat and meat products (sausages, frankfurters, pate, delicatessen meats and narezoci); unpasteurized milk and dairy products such as soft cheeses, creams / spreads, butter, especially if made ​​from unpasteurized milk; fresh or smoked fish and seafood; frozen meat and meat products; fresh and frozen fruits and vegetables; pre-prepared salads and sandwiches, iz’rteni seeds ready for consumption.

Infection can be transmitted through contaminated fresh vegetables and fruits, especially watermelon and cantaloupe (known epidemics in the world). Other routes of transmission of infection can include: direct contact with infected animals, their organs, tissues and secretions or contaminated environment. Pregnant women can pass the infection to newborn through the placenta or during birth.


Laboratory tests prove infection with listeria, are performed on samples of blood or cerebrospinal fluid (liquor). Make and laboratory tests of food and environmental samples, to track down the source of Listeria.


Treatment with appropriate antibiotics.

How to avoid this disease (preventive measures)

Prevention measures are similar to those of other diseases that are transmitted through food and zoonoses.

  • Do not consume raw foods of animal origin, animal products thoroughly thermally processed – long enough and high enough temperatures.
  • Pre-prepared (finished and semi-finished products) and frozen meals and fast food should not be kept too long and need to be re-heated before serving, but not more than once.
  • To consume only pasteurized milk and milk products prepared exclusively from pasteurized milk because pasteurization process comes to the destruction of bacteria.

Temelno • Wash hands, work surfaces and used kitchen utensils and accessories before and after food preparation / handling.

  • Frequent and thorough cleaning or refrigeration storage area and the food.
  • Fresh vegetables, fruits and salads have long and thoroughly washed under running water strong – before eating, slicing or cooking, even when peeled.

People at higher risk – those with weakened immune systems, the elderly and pregnant women in particular should put special emphasis on recommended measures to avoid consumption of soft cheeses, creams and spreads, nepasterizirani dairy products, meat products – frankfurters, pates, gourmet delicatessen products and salads, to avoid food from culinary stalls, fast food, not once oladenata Reheated foods, and avoiding contact with pregnant or newborn animals.


There is no vaccine against listeriosis.

MEASURES IN FOOD production facilities:

If a production capacity conclude foodstuff contaminated with Listeria, then plant that produced contaminated products are thoroughly clean, undergoes proper sanitation, reviewed the application of standard criteria of the HACCP system, hazard analysis and critical control points, until produce products without Listeria monocytogenes.

In addition to the control measures in the production / processing facilities, regulatory agencies in European countries have introduced consumer education to reduce food listeriosis.

This includes education about thoroughly cooking raw animal, thoroughly wash raw vegetables before consumption, keeping raw meat separate from vegetables, not to use raw milk or products made ​​from raw milk, washing hands, washing utensils – knives , cutting boards after handling raw food.