Saturday, July 20, 2013

Why is Listeria so Deadly?

Listeriosis is the disease caused by Listeria Bacteria. If Listeriosis is bad enough to send someone to the hospital it will kill twenty to thirty percent of the patient. But most of the people who get Listeriosis don’t even know it. The CDC doesn't know how many cases there are because many don’t go to the doctor.  If you are a healthy person between the ages of 6 and 65 who is not pregnant, Listeriosis is a  disease called foodborne diarrheal disease, which typically is noninvasive. The median incubation period is 21 days, with diarrhea lasting anywhere from 1–3 days. Patients present with fever, muscle aches, gastrointestinal nausea or diarrhea, headache, stiff neck, confusion, loss of balance, or convulsions.


Nearly all Listeriosis is caused by eating food that has been contaminated with Listeria.When the infected food goes down your throat the listeria encounters your mucus which is covered with Bacteriophage (phage for short). The Phage can kill up to two thirds of the Listeria. Then other beneficial bacteria will produce chemicals that kill listeria and they will eat the food leaving less for the listeria. To finish them off your body can produce chemicals that kill listeria.

If the patient is under six or over 65, or has a weakened immune system or is pregnant the Listeria can cause more serious illnesses. The doctor will take a blood test or do a spinal tap to verify that it is Listeria. Then he will usually treat with Ampicillin which is effective against Listeria.  


One of the things that makes Listeria so dangerous is its ability to go through membranes. It has the ability to go into cells in the body. Once it has gone into a cell it is no longer in danger of being eaten by white blood cells. When it’s in the cell it has the ability to make a protuberance in the cell wall. It uses the protuberance to push into the next cell which it will infect. The Listeria can spread the infection without leaving the cell and being exposed to white blood cells.


The ability of Listeria to go through membranes make it extremely dangerous to fetuses. The fetus doesn't have a developed immune system.The immune system doesn't fully develop until a child is about six years old. Listeria can cause premature birth, death of the fetus or the birth of a child that is infected.


Three serious results from Listeriosis are sepsis, meningitis.and encephalitis. All of these can be deadly.


Sepsis is caused by the immune system's response to a serious infection, most commonly bacteria in the blood or other tissues. Common symptoms of sepsis include those related to a specific infection, but usually accompanied by high fevers, hot, flushed skin, elevated heart rate,hyperventilation, altered mental status, swelling, and low blood pressure. In the very young and elderly, or in people with weakened immune systems, the pattern of symptoms may be atypical, with hypothermia and without an easily localizable infection.  Sepsis causes millions of deaths globally each year
Meningitis is an inflammation of the protective membranes covering the brain and spinal cord. Meningitis can be life-threatening because of the inflammation proximity to the brain and spinal cord.The most common symptoms of meningitis are headache and neck stiffness associated with fever, confusion or altered consciousness, vomiting, and an inability to tolerate light or loud noises.. Children often exhibit only nonspecific symptoms, such as irritability and drowsiness. Meningitis can lead to serious long-term consequences such as deafness, epilepsy, hydrocephalus and cognitive deficits, especially if not treated quickly.
Encephalitis is an acute inflammation of the brain. Adult patients with encephalitis present with acute onset of fever, headache, confusion, and sometimes seizures. Younger children or infants may present irritability, poor appetite and fever. It causes over 100,000 deaths a year.

Even though there are less outbreaks of Listeria than many other food pathogens it is the most 
dangerous.

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