L. Monocytogenes can survive and multiply at the low temperatures typically found in refrigerators. Therefore, the most common way of spread is through food that has been contaminated with L. Monocytogenes. Humans can also spread infection, particularly from pregnant women to unborn children.
Foods like cold deli meats and unpasteurized dairy products are most commonly involved in the faecal-oral route of bacteria transmission. Meat, dairy products, and smoked fish are ready-to-eat foods that need not be heated before consumption. Therefore, these foods are most frequently linked to listeriosis outbreaks.
A mild manifestation of the disease, Non-Invasive Listeriosis primarily usually affects healthy adults named febrile Listeria gastroenteritis. Some symptoms include diarrhea, fever, headache, and myalgia (muscle pain). The incubation time is brief (a few days). Ingestion of foods contaminated with L. Monocytogenes has typically been a factor in outbreaks of this illness.
A more aggressive form of the illness, Invasive Listeriosis, attacks some high-risk populations. These include young children, elderly adults, cancer, AIDS, organ transplant patients, pregnant women, and those receiving treatment.
The symptoms of this type of sickness are severe, and the death rate is significant (20–30%). Fever, myalgia (muscle pain), septicemia, and meningitis are among the symptoms. The incubation phase typically lasts one to two weeks, but it can sometimes be as long as 90 days.
In addition, symptoms like headache, stiff neck, confusion, loss of balance, or convulsions can appear if an infection progresses to the nervous system.
Pregnancy-related illnesses can cause stillbirth, preterm labour, infection of the unborn child, and even mild flu-like symptoms in infected pregnant women.
In addition, the patient’s mental state could be disturbed. They may not be awake and orientated to their name, where they are, or to time.
Using stomach acid suppressors raise the possibility of contracting L. Monocytogenes.
In soil and water, Listeria monocytogenes is present. Therefore, vegetables may become contaminated by the soil or by fertilizer made from manure.
Animals can carry the bacteria without showing symptoms and contaminate animal-derived items, including meat and dairy products.
Uncooked meats and vegetables are only a few examples of raw foods where the bacterium has been discovered.
It has also been found in processed foods contaminated after processing, like cold cuts at the deli counter and soft cheeses.
In addition, the bacterium may be present in unpasteurized (raw) milk or foods produced from unpasteurized milk.
L. Monocytogenes can thrive in a refrigerator. Although L. monocytogenes cannot grow in frozen foods, its growth is facilitated by the moist and cold conditions.
