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E. Coli Symptoms

Escherichia coli bacteria usually live in the intestines of people and animals. Most varieties of E. coli are completely harmless or cause a rather brief diarrhea. But a few particularly nasty strains, such as E. coli O157:H7, can sometimes cause severe abdominal cramps, bloody diarrhea and vomiting. You may be exposed to E. coli from contaminated water or food — especially raw vegetables and undercooked ground meet. Healthy adults usually recover from infection with E. coli O157:H7 within a week, but young children and older adults have a much greater risk of developing a life-threatening form of kidney failure called hemolytic uremic syndrome. Here is what you need to know about E. Coli symptoms.

Early symptoms of E. coli O157:H7

The early symptoms of E. coli O157:H7 infections usually appear about three to five days after a person ingests the bacteria and they include:

  • Nausea
  • Vomiting
  • Stomach cramps
  • Diarrhea that often is bloody
  • Fever of about 100 F to 101 F
  • Loss of appetite
  • Dehydration

Later symptoms E. coli O157:H7 infections

The majority of people that are infected resolve the infection without antibiotics in about five to seven days. However, some people (especially children under the age of 5 and the elderly) develop more severe symptoms, and these people usually require hospitalization and various forms of treatment. These patients develop the usual early symptoms listed above, but do not resolve the infection eventually. They develop symptoms that last longer and, if not treated immediately, the infection may lead to disability or even death in severe cases.

Later symptoms of E. coli infections may include some of the following symptoms:

  • Hemorrhagic diarrhea
  • Anemia
  • Pale skin color
  • Severe dehydration
  • Severe abdominal pains
  • Easy bruising
  • Fatigue
  • Shortness of breath
  • Kidney failure

Risk factors

E. coli can affect anyone who is exposed to the bacteria. But some people are more likely to develop problems than are others. Risk factors include:

  • Age. Young children and older adults are at much higher risk of experiencing the infection caused by E. coli and more-serious complications.
  • Weakened immune systems. People who have weakened immune systems — from AIDS or drugs to treat cancer or prevent the rejection of organ transplants — are much more likely to become ill from ingesting E. coli.
  • Eating certain types of food. Riskier foods include undercooked hamburgers, unpasteurized milk, apple juice as well as soft cheeses made from raw milk.
  • Time of year. Though it's not entirely clear why, the majority of E. coli infections in the U.S. occur from June through September.
  • Decreased stomach acid levels. Stomach acid offers some protection against E. coli. If you take medications to reduce your levels of stomach acid, you may increase your risk of an E. coli infection.

In most cases, home care is all that’s usually required to treat an E. coli infection. Do your best to drink plenty of water, get lots of rest, and keep an eye for more severe symptoms that require immediate help. If you have bloody diarrhea or fever, check with your doctor before taking any antidiarrheal medications. Also, you should always check with your pediatrician before giving medications to infants or children. If dehydration is a concern, your doctor may order hospitalization and intravenous fluids. Most people show improvement within five to seven days after the onset of an infection, and make a full recovery.