Is E. coli Contagious?

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

What is E. coli?

E. coli is a species of bacteria that are gram-stain negative and rod shaped. E. coli commonly live in the intestines of healthy individuals. The complete scientific name of the bacteria is termed Escherichia coli. Most E. coli are harmless to humans, but a few strains of the bacteria can cause symptoms of severe abdominal cramps, bloody diarrhea, nausea and vomiting, dehydration and if not treated, can lead to shock and death. E. coli can cause urinary tract infections, meningitis, pneumonia, abdominal infections as well as sinusitis, osteomyelitis, and sepsis.

Is E. coli contagious?

Some E. coli bacteria are contagious while others are not, depending on the E. coli strain and/or the infection type. Some strains that cause gastrointestinal problems (enteropathogenic E. coli) can be transmitted person-to-person, usually by the oral/fecal route, and even indirectly by contaminated food or water. The E. coli organisms can survive on contaminated utensils and other household items for short time periods. Foods that are sources for diarrhea-causing E. coli include:

  • contaminated meat (raw or undercooked),
  • unpasteurized milk, and
  • raw fruits and vegetables.

In addition, water can be contaminated with E. coli. This can be the source of infection through swimming, drinking, consuming ice and eating any food washed with or exposed to contaminated water.

Other E coli strains that may cause urinary tract infections (UTIs), for example, are not considered to be contagious. Casual contact (shaking hands, kissing) will not usually transmit E. coli person to person. However, some strains of E. coli, including the diarrhea-causing enteropathogenic strains, can be contagious.

Quick GuideDigestive Disorders: Common Misconceptions

Digestive Disorders: Common Misconceptions

Early Symptoms of E. Coli Infection

Early symptoms of E. coli O157:H7 infection usually appear about three to five days after a person ingests the bacteria. Symptoms of E. coli infection are

  • nausea,
  • vomiting,
  • stomach cramps, and
  • diarrhea that often is bloody.

When will I know I'm infected with E. coli (symptoms)?

Symptoms depend on the age of the patient, the strain of E. coli, and the organ system involved and may include:

Some other infections outside the intestinal tract can be caused by E. coli infection. Examples are:

E. coli infection can lead to shock and death if untreated.

How long does it take for symptoms to occur?

The time period from exposure to the E. coli to when disease symptoms develop (incubation period) ranges from about 1 to 10 days and usually occurs in 3 to 4 days. The symptoms an individual may develop vary greatly.

How does E. coli spread?

E. coli is easily spread to other persons by fecal contamination of water and/or food, especially in raw meat, raw milk, and raw vegetables. Many outbreaks of diarrheal illness are spread this way. Moreover, person-to-person contact easily spreads the organisms. Also, indirect spread of E. coli can also occur since the organisms can survive outside the body on utensils and many other surfaces. The organisms can cause wound infections or even spread to the brain (meningitis). If the intestinal tract is injured by trauma, ulceration, or other diseases, it may allow E. coli to cause infection of the abdomen (peritonitis) and/or sepsis.

When do I know I'm cured of E. coli?

Individuals can be cured of E. coli infections. The period of time it takes for antibiotics and/or supportive care (hydration, oxygenation, blood pressure support, for example) to cure E. coli infections varies with the severity of the infection. Some infections can be treated with only antibiotics and cures make take from about 5 - 21 days. Other infections may require surgical drainage and/or debridement. These infections (abscesses, organ infections such as cholecystitis) may increase the time to be cured.

When should I contact a doctor about an E. coli infection?

Most people do not know they are infected by E. coli unless they are informed of an outbreak of E. coli. E. coli can be suggested by their symptoms during an outbreak or if they have ingested contaminated food or fluids. The ultimate diagnosis of E. coli infection is based on the isolation of the organism from the infected site. Consequently, individuals that suspect they have been infected with E. coli should contact a health-care professional urgently. Bloody diarrhea, dehydration, high fevers, severe urinary problems, and mental status changes are conditions that could be due to various serious infections caused by E. coli and must be evaluated emergently.

REFERENCE:

Madappa, T., MD. "Escherichia Coli (E coli) Infections." Medscape. Updated: May 18, 2017.
<https://emedicine.medscape.com/article/217485-overview>

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Reviewed on 10/31/2017
References
REFERENCE:

Madappa, T., MD. "Escherichia Coli (E coli) Infections." Medscape. Updated: May 18, 2017.
<https://emedicine.medscape.com/article/217485-overview>

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