Is E. Coli Contagious? How to Minimize Your Risk of Infection

While foodborne Escherichia coli (E. coli) and viral gastroenteritis (the stomach bug or stomach flu) have similar symptoms, including diarrhea, cramps, and nausea, they are not spread in the same way.

Viral gastroenteritis, for instance, is a highly contagious illness that can easily be transmitted from person to person by, say, sharing a water glass or exchanging a handshake with someone who has been sick with the virus. (1)

How E. Coli Can Spread From Person to Person

A person with a gastrointestinal-related E. coli infection is also contagious if the bacteria can be found in their stool. But their infection is only transmissible by passing traces of their stool on to another. That means, for example, that an infected individual would need to spread their illness by way of improperly washed hands that are contaminated with their infected feces.

Gastrointestinal-related E. coli is most often transmitted to humans in one of the following ways:

• Consuming raw or undercooked beef
• Eating any food that’s been cross-contaminated with raw beef
• Ingesting food contaminated with runoff water: Fruits, vegetables, and grains can become contaminated with E. coli–tinged runoff water from nearby cattle manure (leafy greens are particularly susceptible).
• Neglecting to wash produce properly prior to eating
• Consuming unpasteurized food and beverages, such as juice, cider, or any unpasteurized dairy products, including raw milk
• Neglecting to wash hands thoroughly before and after preparing or eating food; after using the bathroom; or after changing a diaper (2)
  

There are other ways in which individuals can transmit and contract gastrointestinal-related E. coli infections that aren’t related to food. These include:

• Not washing hands after visiting a farm or petting zoo: If you touch an animal or an animal enclosure that’s been E. coli–tainted and then touch your mouth, E. coli can be transmitted.
• Not washing hands after visiting the bathroom or changing a diaper, and then touching your mouth
• Not washing hands prior to touching a baby’s pacifier, bottle nipple, pacifier, or teething toy (2)
  

Swallowing contaminated water in a swimming pool or other body of water where an E. coli infection is present. A report from the Centers for Disease Control and Prevention (CDC) found that 58 percent of the pool filter samples they tested were positive for E. coli. (3)

One of the best way to prevent the spread of E. coli to other people is to maintain proper hygiene. Always wash and scrub your hands carefully with soap and water after you:

• Use the bathroom
• Change a diaper
• Come into direct contact with an animal or its environment, such as the enclosure of a petting zoo or a stable
• Before touching someone’s mouth or any object that will go into someone’s mouth, including food and a pacifier (2)

To actually kill E. coli, wash hands vigorously for a minimum of 20 seconds, the equivalent of singing “Happy Birthday” twice. Contrary to popular belief, warm water is not a must when it comes to killing bacteria and germs; any temperature will do. But don’t forget to always wash the backs of hands, wrists, between the fingers, and under fingernails as well. After hands are dry, use a clean towel to turn off the faucet. (4)

Note that using hand sanitizer does not yield the same protective results as washing hands with warm, soapy water. In fact, the U.S. Food and Drug Administration (FDA) has not approved the use of any hand sanitizer products for preventing an infection from E. coli, though a study shows sanitizer does kill some (but not necessarily all) MRSA germs.

If you’re at a restaurant, there isn’t much you can do to prevent food poisoning from E. coli, aside from sending back any meat that looks like it wasn’t cooked completely, such as pink hamburger meat. But there are a number of steps you can take at home to reduce your risk of getting an E. coli intestinal infection:

• Cook beef thoroughly. To kill E. coli, steaks and roasts need to be cooked to an internal temperature of at least 145 degrees F; ground beef requires a minimum internal temperature of 160 degrees F.
• Rinse all fruits and vegetables. These should be rinsed until no visible grime or dirt is left on the produce. Be sure to also wash fruit like melons. When you cut into, say, a cantaloupe, you can drag surface E. coli through the fruit, contaminating the inside.
• Avoid cross-contamination. Separate raw meats from produce, using different cutting boards and knives when preparing them. Always wash hands, utensils, counters, serving trays, and cutting boards after they’ve been in contact with raw meat. And don’t put cooked meat back on the same plate it was on before it was cooked. (2)

Understanding the Signs of Infection

One of the best ways to avoid spreading your gastrointestinal-related E. coli illness to others is to understand what signs and symptoms indicate that you actually have an infection. These common symptoms include:

• Severe or bloody diarrhea
• Nausea, with or without vomiting
• Severe stomach cramps
• Fatigue
• Low-grade fever (a rare symptom)

But keep in mind that you may still have pathogenic E. coli in your system even if you do not experience any symptoms. In fact, most people with a Shiga toxin–producing  E. coli (STEC) infection — the most common gastrointestinal-related E. coli infection — don’t feel ill until three to four days after consuming something that contained the bacteria.

It’s important to contact your physician if you experience diarrhea that lasts for more than three days, or if your diarrhea is accompanied by high fever, blood in your stool, reduced urine output, or excessive vomiting. (6)