E. coli Infection
E. coli Infection
Learn About E. coli Infection
Escherichia coli (abbreviated as E. coli) are bacteria found in the environment, foods, and intestines of people and animals.
Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The types of E. coli that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or persons.
E. coli can cause diarrhea, urinary tract infections, respiratory illness, and other illnesses. Other kinds of E. coli are used as markers for water contamination—so you might hear about E. coli being found in drinking water, which are not harmful, but indicate the water is contaminated. It does get a bit confusing—even to microbiologists.
Different kinds of E. coli
Some kinds of E. coli cause disease by making a toxin called Shiga toxin. The bacteria that make these toxins are called "Shiga toxin-producing" E. coli, or STEC, for short.
The most commonly identified STEC in North America is E. coli O157:H7
Other kinds of E. coli in the STEC group, including O145, are sometimes called "non-O157 STECs."
E. coli strains that cause illness are categorized into 6 types found here.
What are Shiga toxin-producing E. coli?
Some kinds of E. coli cause disease by making a toxin called Shiga toxin. The bacteria that make these toxins are called "Shiga toxin-producing" E. coli, or STEC. You might hear them called verocytotoxic E. coli (VTEC) or enterohemorrhagic E. coli (EHEC); these all refer generally to the same group of bacteria.
The most commonly identified STEC in North America is E. coli O157:H7 (often shortened to E. coli O157 or even just "O157"). When you hear news reports about outbreaks of "E. coli" infections, they are usually talking about E. coli O157. Other kinds of E. coli in the STEC group are sometimes called "non-O157 STECs."
E. coli serogroups: STEC O157 and non-O157 STECs
In addition to E. coli O157, many other kinds (called serogroups) of STEC cause disease. Other E. coli serogroups in the STEC group, including E. coli O145, are sometimes called "non-O157 STECs." Some types of STEC frequently cause severe disease, including bloody diarrhea and hemolytic uremic syndrome (HUS), which is a type of kidney failure.
- Currently, there are limited public health surveillance data on the occurrence of non-O157 STECs, including STEC O145; many STEC O145 infections may go undiagnosed or unreported.
- Identifying non-O157 STEC infections is more complex than identifying those from STEC O157. First, clinical laboratories must test stool samples for the presence of Shiga toxins. Many clinical laboratories do not test for non-O157 STEC. Then, the positive samples must be sent to public health laboratories to look for non-O157 STEC.
- Other non-O157 STEC serogroups that often cause illness in people in the United States include O26, O111, O103, and O145.
About the Illness
- People usually get sick from STEC within 2 to 8 days (average of 3 to 4 days) after swallowing the organism. Most people infected with STEC O145 develop diarrhea (usually watery and often bloody) and abdominal cramps. Most illnesses resolve on their own within 7 days. Some illnesses last longer and can be more severe.
- Most people recover from their illness within a week but, rarely, some develop a more severe infection. HUS can begin as the diarrhea is improving.
- Hemolytic uremic syndrome (HUS), a type of kidney failure, can begin as the diarrhea is improving. HUS can occur in people of any age but is most common in children under 5 years old and the elderly.
Some people are more at risk for infection from E. coli and other germs
- Escherichia coli O157:H7 and other STEC strains are a common cause of bacterial gastrointestinal illness in the United States, but illness can be severe, especially in young children or the elderly. HUS can occur in people of any age but is most common in children under 5 years old and the elderly. HUS occurs in 5%–10% of patients. E. coli O157 infection is the most common cause of HUS in children.
CDC's role in food safety—investigating outbreaks of foodborne illness
CDC leads federal efforts to gather data on foodborne illnesses, investigate foodborne illnesses and outbreaks, and monitor the effectiveness of prevention and control efforts. CDC is not a food safety regulatory agency but works closely with the food safety regulatory agencies, in particular, with the Food and Drug Administration and the Food Safety and Inspection Service of the U.S. Department of Agriculture.
CDC also plays a key role in building state and local health department epidemiology, laboratory, and environmental health capacity to support foodborne disease surveillance and outbreak response. Notably, CDC data can be used to help document the effectiveness of regulatory interventions.
Information about outbreaks of E. coli infections since 2006 that cross multiple states can be found at http://www.cdc.gov/ecoli/outbreaks.html.
To best protect yourself against E. coli infections
- Know your risk of food poisoning. People at higher risk for foodborne illness are pregnant women and newborns, children, older adults, and those with weak immune systems.
- Consult your healthcare provider if you think you might be ill with E. coli infection.
- Practice proper hygiene, especially good hand washing
- Wash your hands thoroughly after using the bathroom or changing diapers and before preparing or eating food. Wash your hands after contact with animals or their environments (at farms, petting zoos, fairs, even your own backyard).
- Always wash your hands before preparing and feeding bottles or foods to your infant, before touching your infant's mouth, and before touching pacifiers or other things that go into your infant's mouth.
- If soap and water aren't available, use an alcohol-based hand sanitizer. These alcohol-based products can quickly reduce the number of germs on hands in some situations, but they are not a substitute for washing with soap and water.
- Keep all objects that enter infants' mouths (such as pacifiers and teethers) clean.
- Cook meats thoroughly. Ground beef and meat that has been needle-tenderized should be cooked to a temperature of at least 160°F/70˚C. Use a thermometer to verify the temperature, as color is not a very reliable indicator of how thoroughly meat has been cooked.
- Avoid consuming raw milk, unpasteurized dairy products, and unpasteurized juices (like fresh apple cider).
- Avoid swallowing water when swimming or playing in lakes, ponds, streams, swimming pools, and backyard "kiddie" pools.
- Prevent cross-contamination in food preparation areas by thoroughly washing hands, counters, cutting boards, and utensils after they touch raw meat.
- Please see http://www.foodsafety.gov/poisoning/causes/bacteriaviruses/ecoli/ for information on what you can to prevent from getting infected with E. coli.
- CDC E. coli website
- See multistate E. coli outbreaks
- See select publications
- Resources for clinicians
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