Orange County home page

E. coli

What is E. coli?

E. coli is a common kind of bacteria that lives in the intestines of animals and people.  There are many strains of E. coli and most do not cause serious illness.  However, there are some strains that produce a toxin that can cause severe illness.  These strains are called “shiga toxin-producing E. coli”.  E. coli 0157:H7 is the name of one of the most common toxic strains of this type of bacteria. It is found in the intestines of some cattle, deer, goats and sheep.



How can I tell if I have an E. coli infection?

People with E. coli infection usually have a sudden onset of diarrhea, often with visible blood, and stomach cramps.  Most people have no fever or a very low-grade fever.  A stool sample tested specifically for E. coli is the best way to determine if someone is infected.

Taking antibiotics or over-the-counter anti-diarrhea medicines can make the infection worse.  Call your doctor if you experience sudden diarrhea with blood in it. 

Is E. coli infection dangerous?

Yes, it can be dangerous for some.  It is especially dangerous for children under the age of five and for the elderly or adults with weakened immune systems.  The bacteria can cause kidney failure and bleeding and can lead to death.  


How is E. coli spread?

E. coli bacteria are spread by eating and drinking contaminated food or water, or by putting contaminated objects or hands into the mouth. 

  • The bacteria can be accidentally mixed into ground beef or raw meat before packaging. 
  • If there are bacteria on the udder of a cow during milking, it can contaminate the milk.
  • Sewage and rainwater runoff from contaminated soil can introduce the bacteria into lakes, ponds, rivers, swimming pools, and wells. 
  • Raw vegetables, fruits and sprouts grown or washed in contaminated water can spread E. coli.
  • Poor handwashing after a bowel movement or changing a diaper allows bacteria to remain on the hands then get transferred to food and drink or other objects that may go into someone else’s mouth and cause infection. 


What can I do to protect myself and my family from E. coli?  

Follow these tips to prevent E. coli infection:

  • Cook ground beef to 160 degrees Fahrenheit. Measure the temperature by inserting a meat thermometer into the thickest part of the meat. 
  • Do not eat ground beef that is still pink in the center. If a restaurant serves you under-cooked hamburger, send it back for more cooking.  Ask for a fresh bun and clean plate, too.
  • In your kitchen, keep raw meat away from other foods.  Wash hands, cutting boards, countertops, dishes, knives and forks in hot, soapy water after contact with raw meat, spinach greens or sprouts. Wash the meat thermometer after use.
  • Never put cooked meat back onto the plate they were on before cooking.
  • Avoid non-pasteurized milk, milk products, cheeses, juices and ciders.
  • Drink water from safe sources, such as municipal water that has been treated, well water that has been tested, or bottled water. 
  • Avoid swallowing lake or pool water while swimming. 
  • During an outbreak of E. coli, follow instructions given by public health officials.
  • Wash fresh fruits and vegetables well under running water.
  • Boil fresh vegetables for 1 full minute before serving.
  • Always wash your hands well after using the bathroom and before handling food or drink.

Where can I find more information?

Return to Top of Page | Back to Topics