Listeria is found
mostly in nature; in places such as soil. What causes human relations is when
the pathogen form of listeria is food borne and infects humans.
Listeria monocytogenes
is the only form of listeria that causes listeriosis out of all 8 types of the
bacteria. It has the ability to survive extreme cold and heat, so it doesn't die through food
processing. When humans or animals consume bacteria infected foods, they may
develop the listeriosis illness. Once the listeria bacteria leaves the
digestive system and goes into the blood stream, the host is then infected with
listeriosis and begins to show symptoms.
The listeria bacteria
can be contracted through eating or touching soft dairy products (like cheese),
vegetables, fish, or meats that are contaminated and were not prepared
properly. It has the highest death rate (25%) of all food borne illnesses.
In many healthy
children and adults (under age 60) the bacteria will be eliminated before it
causes any symptoms or show very mild and non life threatening symptoms. In
fact, 5-10% of humans and animals are found to have the bacteria in their
digestive system, and show no symptoms.
In other cases, the
bacteria will infect people who have weakened immune systems, such as pregnant
women, ill, or the elderly. In this case, listeriosis can be life threatening
causing symptoms such as: meningitis, nausea, cramps, diarrhea, brain/blood
infections, and other flu like symptoms. During pregnancy, the listeria bacteria
are able to pass through the placental barrier and infect the fetus causing
stillbirth or miscarriages.
