Escherichia coli, also known as E. coli in short, is a type of bacteria that is commonly found in the intestines of healthy people and warm-blooded animals. Most strains of E. coli are harmless, but some strains like O157: H7 and E. coli O104:H4 can cause serious health problems. While healthy adults usually recover from the infection in a week, young children, older adults, and people with weakened immune systems are more vulnerable and may develop serious complications.
E. coli infections are generally caused by contaminated food or water and can also be easily spread from person to person. E. coli is mostly found in improperly cooked meat, raw fruits, uncooked vegetables including sprouts, untreated drinking water, unpasteurized (raw) milk or (raw) milk products, unpasteurized apple juice/cider, and direct contact with animals at petting zoos or farms.
An outbreak of E. coli infection in 2000 in Walkerton, Ontario killed seven people and made more than 2,300 others ill. The Walkerton E. coli outbreak occurred when Escherichia coli bacteria contaminated the water supply of the small community of Walkerton. Canada normally deals with a few thousand cases of E. coli illness a year.
Symptoms of E. coli infections
Symptoms of E. coli infections usually appear within 3 to 4 days after exposure, but the incubation period can vary from 1 to 10 days. Symptoms can include severe abdominal cramping, nausea, vomiting, and diarrhea, which may range from mild and watery to severe and bloody. Some people may show no symptoms at all but can still carry the bacteria and pass it on to others.
In most cases, healthy adults recover from E. coli illness within five to ten days. However, in a small number of cases, E. coli contamination can lead to hemolytic uremic syndrome (HUS), a life-threatening condition that requires treatment in intensive care units.
How to prevent E. coli infections
To prevent the spread of E. coli, proper hygiene, safe food handling, and preparation practices are important. It is also a good idea to keep pets away from food storage and preparation areas.
Testing for E. coli
The presence of Escherichia coli (E. coli) bacteria in food and water serves as an important indicator of potential fecal contamination and the potential introduction of harmful bacteria. While the concept of employing E. coli as an indirect marker for health risks holds scientific merit, practical implementation is complicated due to the coexistence of other enteric bacteria such as Citrobacter, Klebsiella, and Enterobacter, which share similarities with E. coli. To encompass this group of related bacteria, the term “coliforms” is employed.
Coliform testing plays a crucial role in assessing the hygienic quality of water and serves as a general gauge for the sanitary conditions prevailing within food processing environments. Notably, fecal coliforms are the preferred standard indicator for shellfish and their aquatic habitats. Escherichia coli, in particular, is used as an indicator of recent fecal contamination or suboptimal sanitary practices during food processing.
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