Listeria POST-DOC

Listeria monocytogenes

Listeria monocytogenes is an intracellular pathogenic bacterium widely distributed in in soil, decaying vegetation soil sewage, animal feces, river and canal waters, fertilizers, plants and animals. Its ubiquitous nature derives from pathogen’s ability to adapt to an extended variety of adverse conditions, thus surviving and, in some cases, proliferating in substrates that are considered for human consumption as well as in the human gastrointestinal tract.

Foodborne listeriosis is one of the most severe foodborne diseases with high hospitalization and mortality rates (20-30%) especially in vulnerable populations, such as immuno-compromised people, pregnant women, and the elderly. Therefore, it is considered as one of the most serious foodborne human diseases under surveillance.

Listeriosis

Listeriosis can be invasive or noninvasive. Invasive listeriosis is the severe form of the disease and it is characterized by severe symptoms, such as fever, myalgia, septicemia, and meningitis. The incubation period is usually 1-2 weeks but varies between a few days and up to 90 days. Contrary to this form, the noninvasive listeriosis is a mild disease with a short incubation period (few days) and symptoms that include fever, headache, and diarrhea.

In 2016, listeriosis was the most severe foodborne illness in Europe with 2536 reported cases and 247 deaths. In the meantime, it is estimated that 1,600 people get listeriosis and approximately 260 die each year in the U.S.

Even though listeriosis is rarely reported in Africa, Asia and South America, the world’s largest listeriosis outbreak occurred in South Africa and was linked to the consumption of a ready-to-eat processed meat product called “Polony” resulting in 1,060 infections and 216 deaths.

Food has been recognized as a primary vehicle of transmission for human disease within the last 30 years. Human foodborne listeriosis is mainly associated with the consumption of poultry, beef and dairy products. Nevertheless, the last decade the majority of listeriosis infection has been mainly associated with dairy products and fresh produce consumption, resulting in hundreds of illnesses, hospitalizations, deaths and product recalls.