Escherichia coli (E. coli) is a type of bacteria found in the digestive tract. It’s mostly harmless, but some strains of this bacteria can cause infection and illness. E. coli is typically spread through contaminated food, but it can also pass from person to person. If you receive a diagnosis of an E. coli infection, you’re considered to be highly contagious.

Not all strains of E. coli are contagious. However, strains that cause gastrointestinal symptoms and infection are easily spread. The bacteria can also survive on contaminated surfaces and objects for a short period of time, including cooking utensils.

Infectious E. coli bacteria can be spread from humans and animals. The most common ways it spreads are:

  • eating undercooked or raw meat
  • eating contaminated, raw fruits and vegetables
  • drinking unpasteurized milk
  • swimming in or drinking contaminated water
  • contact with a person who has poor hygiene and doesn’t wash their hands regularly
  • contact with infected animals

Anyone has the potential to develop an E. coli infection if they’re exposed to the bacteria. However, children and elderly people are more susceptible to this infection. They’re also more likely to experience complications from the bacteria.

Other risk factors for developing this infection include:

  • Weakened immune system. People with a compromised immune system — more so from disease, steroids, or cancer treatment — are less able to fight off infection. In this instance, they’re more likely to develop an E. coli infection.
  • Seasons. E. coli infections are most prominent during the summer, specifically June through September. Researchers are unsure why this is so.
  • Stomach acid levels. If you’re taking medication to decrease stomach acid, you may be susceptible to this infection. Stomach acids help provide some protection against infection.
  • Eating raw foods. Drinking or eating raw, unpasteurized products can increase the risk of contracting an E. coli infection. Heat kills bacteria, which is why eating raw foods puts you more at risk.

An onset of symptoms may begin 1 to 10 days after exposure. Symptoms can last anywhere from 5 to 10 days. Although they vary from one person to the next, the most common symptoms include:

If you have a more severe E. coli infection, you may experience:

If left untreated, a severe E. coli infection can cause other severe infections of the GI tract. It can also be fatal.

There’s no vaccine to prevent you from contracting an E. coli infection. Instead, you can help prevent spreading this bacteria through lifestyle changes and best practices:

  • Cook meats thoroughly (especially ground beef) to help eliminate unhealthy bacteria. Meat should be cooked until it reaches 160ºF (71ºC).
  • Wash raw produce to remove dirt and any bacteria hanging onto leafy vegetables.
  • Thoroughly wash utensils, cutting boards, and countertops with soap and hot water to avoid cross contamination.
  • Keep raw foods and cooked foods separate. Always use different plates or wash them completely before reuse.
  • Maintain proper hygiene. Wash your hands after using the bathroom, cooking or handling food, before and after meals, and after coming in contact with animals.
  • E. coli, avoid public areas until your symptoms are gone. If your child has developed an infection, keep them home and away from other children.