Food borne illnesses: Part 1 - E. Coli

What is a food borne pathogen?

A food borne pathogen is some sort of disease (pathogen) that can be transmitted to you by eating food contaminated with it. This can include everything from bacteria to toxins to parasites. It’s important to note that not every piece of meat or raw vegetable has a pathogen on it. They must be first contaminated, and thanks to strict laws and public awareness this is typically enforced in the United States.

How does it get on my food?

There are a lot of different ways that depend on the type of pathogen. Sometimes run off from cattle infected with that pathogen get on fruits and vegetables, or sometimes the plants are watered with contaminated water. Either way, the affected food source must be exposed to the pathogen.

What are the main types of food born pathogens?

There are a lot of different pathogens that can cause infection, so I’ll break this down by the most common/most recent outbreaks.

E. Coli

Everyone has heard of E. Coli, a popular member of the enterobacteriaceae family. These are known for being gram negative rods that are commonly found in your GI tract. However, some strains of E. Coli are known for being particularly dangerous. We all remember the E. Coli contaminated spinach from 2006, or Tyson’s recent recall of ground beef.  As you can see, E. Coli isn’t just a carnivore or vegetarian disease. People made ill by this disease did so by ingesting unwashed or uncooked spinach or meat not fully cooked (the CDC recommends cooking your food to 165 degrees fahrenheit to kill most pathogens). Ready for the gross facts? E. Coli is transmitted by the fecal-oral route. This means that something ate the E. Coli, it passed through their GI tract and was shed in their feces. In order to get sick you have to ingest part of the feces, or come in contact with contaminated feces and then ingest them. This can be everything from an infected person not washing their hands after using the bathroom to contamination at the packaging plant.

One of the more troubling aspects of E. Coli rests with cattle. Cattle can be infected by E. Coli O157:H7 (the most dangerous hemorrhagic form of the disease) and show absolutely no symptoms and is therefore considered part of their normal flora. Because of this they shed it in their feces if left untreated. Since they don’t cause disease in the cattle they’re considered a common commensal. Some research is currently being done to create a “vaccine” for cows that doesn’t allow them to shed the E. Coli, however this is a long way off. The fact that cattle are asymptomatic carriers makes contamination a big issue. As stated before, the bacteria is passed via feces. Feces that runs into water can contaminate the water, as was the suspected case in the spinach outbreak. Unsanitary conditions in a slaughterhouse can also lead to contamination. Some research has shown that up to 89% of beef sold in the US is contaminated with E. Coli, but since I could not find the original source, I will leave you with this site to decide for yourself.

The symptoms of this E. Coli are consistent with the type of E. Coli it is: enterohemorrhagic. It targets large intestinal cells and uses an AB toxin to cause symptoms. Sometimes the disease can lead to hemolytic-uremic syndrome, where the toxins can affect the endothelial cells in the kidney and brain. Those infected typically have large amounts of mucoid bloody diarrhea that can last from days to weeks. This leads to dehydration and weakness if not treated.

If you think you are infected by E. Coli it is highly recommended that you seek medical attention as soon as possible. Through antibiotics and fluid therapy a healthy person can recover in a short time. Children, immunocompromised persons and children are at particular risk for death.