(CNN) -- Here's everything you need to know about E. coli and the outbreaks surrounding its many different strains.
There are many strains of the bacteria Escherichia coli (E. coli). Most strains are harmless and live in the intestines of healthy humans and animals. Some kinds of E. coli cause disease by producing Shiga toxin. The bacteria that make these toxins are called "Shiga toxin-producing" E. coli (STEC). The most commonly found STEC in the United States is E. coli O157:H7.
The symptoms of STEC infections can include:
Some infections are mild, but others can be life-threatening.
The CDC estimates that 265,000 STEC infections occur each year in the United States. E. coli O157:H7 causes more than 36 percent of these infections. People of all ages can be infected, but young children and the elderly are more likely to develop severe symptoms.
The types of E. coli that can cause illness can be transmitted through contaminated water or food, or through contact with animals or people.
To avoid E. coli infections, experts advise to thoroughly cook meat, avoid unpasteurized dairy products and juices, avoid swallowing water while swimming, and wash hands regularly.
1998: The Hazard Analysis and Critical Control Points program (HACCP) begins requiring meat processors to establish critical checkpoints in the plants to prevent pathogens from contaminating meat.
- Inspectors from the food-safety agency randomly test all facilities that grind meat products to make sure that the plants are complying with the HACCP program.
1999: The USDA approves the irradiation process for meat. Irradiation is a process that uses beams of high-speed electrons to kill E. coli and other bacteria.
May 2000: Huisken Meats of Sauk Rapids, Minnesota, becomes the first meat processor to begin selling irradiated ground beef to retailers.
June 2009: Epitopix LLC, a Minnesota-based veterinary pharmaceutical company, begins licensing a new vaccine for cows that reduces the transmission of E. coli between cows and humans.
ConAgra Beef Co. (E. coli O157:H7)
Taco Bell/Taco John's (E. coli O157:H7)
Topp's Ground Beef Patties (E. coli O157:H7)
Cheese (E. coli O157:H7)
Chipotle (E. coli O26)
I.M. Healthy Brand SoyNut Butter (E. coli O157:H7)
Romaine Lettuce (E. coli 0157:H7)
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