
All About E. coli O157:H7
What is E.Coli O157:H7? | Where does it come from? | How does it infect people? | Symptoms and risks.
What is E. coli O157:H7?

Escherichia coli (E. coli) are bacteria commonly found in the intestines of animals and humans and there are specific strains which are a leading cause of food borne illness in humans. According to the Centers for Disease Control (CDC) in Atlanta, Georgia, 73,000 people get sick and 61 people die from E. coli-related infections every year in the United States.
There are many different strains of E. coli; most live in the human intestine and cause no disease. However, one of the most familiar E. coli strains—O157:H7—releases toxins that can cause severe illness in humans. This strain is also known as an enterohemorrhagic E. coli (EHEC) or Verotoxinogenic E. coli (VTEC), reflecting the human illness it can cause.
E. coli O157:H7 infection is a foodborne “zoonotic disease”. O157:H7 was first identified in 1982 during an outbreak of severe bloody diarrhea in the United States which was traced to contaminated hamburgers. Since then, more E. coli O157:H7 infections in the U.S. have been traced back to eating undercooked ground beef than any other food.
In recent years, the organism has become a global health problem. In 1996 alone, major outbreaks were reported in Germany, Scotland, and Japan. The largest of these outbreaks, in Japan, affected approximately 9,000 people. The original emergence of this pathogen and its spread across the world is likely the result of the genetic evolution of bacteria, leading to a new strain.
Human illness caused by zoonotic disease is expected to continue to increase with ongoing changes in food and agriculture practices, deforestation and urbanization of virgin areas, globalization of the live animal and animal product trade, and climate changes (MacKenzie et al, 2004).