Vigilance is required to avoid E. coli sickness

  • It is important to thoroughly wash lettuce and produce, which can become contaminated with the E. coli bacteria when growing in fields or being transported to stores.

    It is important to thoroughly wash lettuce and produce, which can become contaminated with the E. coli bacteria when growing in fields or being transported to stores. Stock Photo

By Dr. Eve Glazier and Dr. Elizabeth Ko
Posted10/1/2022 7:00 AM

Q: It seems like there's a new E. coli outbreak every month. We never worried because we're careful about washing our produce, but our son-in-law got pretty sick with it after eating a fast-food hamburger. How dangerous is E. coli? Where does it come from? Is there any way to avoid it?

A: E. coli is short for Escherichia coli. It's a large and diverse group of bacteria that make their home in the lower intestines of humans and some animals. It can also be found in food, untreated water and the environment.


As is the case with so many types of disease and illness, infection with E. coli can range from very mild to quite severe. In some cases, it can lead to death. How sick someone gets depends on the specific strain of E. coli that is involved.

Most strains of the bacteria are harmless. It may come as a surprise, but "good" E. coli are a natural part of the flora in our gut microbiome. They help with the synthesis of certain vitamins and also play a role in preventing certain pathogens from colonizing the colon. But several different strains cause illnesses, including diarrhea, urinary tract infections, respiratory illnesses, pneumonia and neonatal meningitis.

Infection with E. coli typically occurs by ingesting contaminated fecal material. This can be through eating raw or prepared foods, or from touching a contaminated surface and then touching your mouth. Infections have also occurred from contact with farm animals or at a petting zoo.

Symptoms begin from two to five days after infection. Abdominal pain, abdominal tenderness and cramping are soon followed by an extended bout of diarrhea. As the infection progresses, this becomes increasingly watery. Some strains of E. coli damage the inner lining of the small intestine, which can cause a bloody discharge. Additional symptoms can include nausea, chills, fever and headache.

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In healthy individuals, the disease lasts about a week. Treatment consists of supportive care to maintain hydration and electrolytes.

A rare but dangerous kidney complication known as hemolytic uremic syndrome can occur in individuals whose immune systems are not robust. Infants and older adults with an E. coli infection are at particular risk. Symptoms include a decrease in the frequency of urination, exhaustion and a loss of pink color in the cheeks and the insides of the lower eyelids. This is a medical emergency and requires immediate hospitalization.

Unfortunately, you can't completely eliminate the risk of E. coli infection. However, you can minimize it. Your practice of thoroughly washing produce before preparing and serving is a good one. You should also always cook meats to their recommended internal temperature. Avoid cross-contamination by immediately cleaning any utensil or surface that has come into contact with raw meat. Staying vigilant about hand hygiene is also important. Always wash your hands thoroughly after using the bathroom, changing a baby's diaper or helping someone else use the toilet.

You should also wash hands before handling and preparing food and after contact with animals.

COVID-19 boosters

Q: The new COVID-19 boosters are here, and I'm not sure if, or when, I need to get one. I had the two-shot Moderna series last winter. I had a mild case of COVID-19 this summer. When I got better, I got the booster. Do I still need to get another one? Am I the only one who is confused?

A: You are not alone in wondering about the new boosters. The coronavirus landscape has undergone continual change, and it's not a surprise there's some confusion.


The modifications to advice about how and when to get a COVID-19 vaccine have been due, in part, to the steep learning curve we faced with this new disease. And when it comes to the new boosters, the basic nature of viruses has played a big role. The good news is our immune systems learn from each encounter with these pathogens. But because viruses continually mutate, they can stay one step ahead of our body's defenses. When an altered version of an original virus becomes successful enough to spread widely, it's known as a variant. And with the emergence of the omicron variant, the original coronavirus vaccine needed a tweak to be more effective.

At this time, more than 90% of new COVID-19 cases nationwide are being caused by infection with the omicron variant. It's a great relief, then, that a new tool in the fight against the disease is now available. The reformulated boosters, known as a bivalent vaccine, include components of both the original virus strain that triggered the COVID-19 epidemic and the now-dominant omicron versions, BA.4 and BA.5. The result is broader protection against the coronavirus and its most widely seen variant. By staying up to date with the newest vaccine, you have improved protection against severe illness, hospitalization and death.

The FDA has authorized the bivalent formulations of the Moderna and Pfizer COVID-19 vaccines -- aka the omicron boosters -- for those who have completed their original two-dose vaccine series. The Pfizer version is available to individuals 12 years of age and older. The new Moderna booster is authorized for everyone 18 years of age and older. Each of these boosters is given as a single-dose shot.

This bivalent booster is recommended to everyone who is eligible, no matter how many previous boosters someone has had. However, there are some requirements when it comes to timing. The FDA set a wait period of at least eight weeks between the last dose of the original booster and getting a shot of the new omicron bivalent version. This is to optimize your immune response, and thus give more robust protection.

There's also a wait period for people who have recently had COVID-19. The FDA and the CDC recommend waiting at least 12 weeks after recovery from coronavirus infection to get the new booster. Again, this is to boost immune response.

And to those of you who have been asking, yes, you can get a flu vaccine and the new omicron booster at the same time.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to

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