Public Health

McDonald's E. coli outbreak, new COVID and flu tests, plus bird flu 2024 and the latest H5N1 news

. 10 MIN READ

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Is it safe to eat McDonald's? Are expired COVID tests accurate? Where can I get a COVID test over the counter? Is there human to human bird flu transmission?

AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH, discusses the E. coli outbreak at McDonald's and food safety issues, bird flu symptoms in humans, at-home COVID-19 test kits and when you should test for COVID. AMA Chief Experience Officer Todd Unger hosts.

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  • Andrea Garcia, JD, MPH, vice president, science, medicine & public health, American Medical Association

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Unger:  Hello and welcome to the AMA Update video and podcast. Today we have our weekly look at the headlines with the AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia. I'm Todd Unger, AMA's chief experience officer. Andrea, it's great to see you today. 

Garcia: Yeah, great to see you too. Thanks for having me back. 

Unger:  Well, this episode of the Updates got it all. We've got bird flu, new COVID and flu test, and Quarter Pounders. Never thought I would say that on the AMA Update, but here we are. Andrea, let's start with the bird flu. Last time we talked, we were waiting for blood work to see if a case in Missouri had involved human to human transmission. Have we gotten those results? 

Garcia: Yeah. So as a quick reminder, that Missouri patient is the first known person with H5 bird flu in the U.S. without any apparent exposure to infected animals. That's serology blood tests that we've been waiting on were really specialized tests conducted by the CDC looking for antibodies in people who had come in close contact with that patient, including health care professionals and one person who lived with that patient. 

The five health care professionals were definitively seronegative against H5 in all of those assays, which means they were not infected with H5 bird flu. The household contact showed evidence of an antibody immune response to H5 in only one, but not the other serologic assays. So it's possible they may have been exposed to H5 despite not meeting that accepted threshold for seropositivity. 

Unger:  Now, I'm just going to say that's a little bit confusing. So what do we take away from these results? Is the evidence of human-to-human transmission there or no? 

Garcia: Yeah. So according to the CDC, this finding rules out person to person spread between the Missouri patient and those five health care professionals. Symptoms reported by these contacts were not the result of an exposure to that Missouri patient. 

Now, the household contact and the patient had similar immunologic results, identical symptom onset dates. And the CDC indicated that this really supports a single common exposure to bird flu rather than person to person spread. 

So there was a briefing last Thursday, and CDC officials explained that that household contact actually would not be counted as an official case because they didn't test positive on at least 2 of the 3 ways to test for infection that are accepted by the CDC and the WHO. 

So for now, the total of H5 infections this year in the U.S. is 36 reported cases in 2024. Overall, the Missouri results were considered good news by infectious disease experts, and they provide evidence that bird flu is not spreading between people in any sort of sustained way. However, there are still, of course, some unanswered questions. 

Unger:  So basically, to summarize, relief that there's no evidence of human-to-human transmission there, but a lot of questions remain to be answered. A bit of mystery here. Can you take us through what questions are being asked? 

Garcia: Well, I think for one, both people in Missouri who tested positive for H5 didn't have typical flu symptoms. They had GI issues, including diarrhea, which initially led investigators to suspect that food poisoning might be the cause. 

Now, as some experts point out, it's unclear whether the H5N1 virus was causing those symptoms or whether they might have been or they might have had more than one infection at the same time. I think we also still have no idea how the patient and the housemaid initially were exposed to the virus. 

Unger:  And I imagine as time goes on, it gets more and more difficult to detect these cases, especially as we get into the fall and winter months. 

Garcia: Yeah, I think that's likely true. And I think while testing for each bird flu will be getting easier, as we learned last week, it will soon be available through several commercial labs, including Quest Diagnostic. Detecting these cases may become more difficult as respiratory viruses circulate in the fall and winter months. 

The CDC is going to continue to look for unusual activity. And we know that wastewater can detect influenza A H5. But there are limitations. For example, once detected, we can't tell the source. It could be from a person, a cow or from discarded contaminated milk. 

I think the best thing anyone can do right now is to get the vaccines that they are eligible for. The AMA did issue a press release on Monday with this exact message, strongly urging everyone who is eligible to get vaccinated against flu, COVID and RSV as soon as possible before those viruses begin spreading in their communities. 

Unger:  That's definitely a good idea and a great reminder. And we're going to be talking with Dr. Sandra Fryhofer, the AMA's liaison to ACIP, about the expanded guidelines for some of those vaccines next week. There's also a new at-home test that can make things a little easier this fall and winter. Andrea tell us more about that. 

Garcia: Well, Todd, according to a recent article that was in The New York Times, we actually now have nine at-home tests that can detect both COVID and flu. And many of these tests, which can be sold over the counter, were just approved within the last six months or so. They typically test for COVID and then two common flu viruses. So influenza A and influenza B. 

They test, look and work a lot like the traditional at-home COVID tests. So, you swab the inside of your nostril, dunk it in the solution and squeeze those droplets onto a test strip. And then the results are delivered within 15 minutes. 

As with at-home COVID tests, the combination tests likely work best when you have symptoms, and they're only slightly more expensive than a regular COVID test, usually around $30 for a pack of two. As you mentioned, these common combination tests will be really important as we head into these colder months and peak virus season. But really, people need to know that they exist, they need to be able to access them and they need to know how to use them. 

Unger:  Andrea, effectiveness of these tests, what do we think? 

Garcia: Well, they're about as effective as the COVID only test, which FDA has said should be able to detect the virus at least 80% of the time when someone is infected. Most of the new products are antigen tests, meaning they pick up specific viral proteins. 

There is one test made by Pfizer that is a molecular test, which is more sensitive because it searches for genetic material. That test is pricier, at around $40. These tests are certainly going to be helpful in letting people early in the course of their disease, which illness they have so that they can get timely and appropriate treatment. 

Unger:  And that's a key point because we know it's so important with both COVID and the flu to get treatment early. So, thank you for that update. Andrea, we're going to switch topics now to something that's been making headlines over the past week. It's an E. coli outbreak at McDonald's. What's going on there? 

Garcia: Well, Todd, according to articles that have been published in The Washington Post and The New York Times last Friday, this outbreak has widened to include 75 people across 13 states. And originally, the Quarter Pounder beef patty was thought to be the culprit. And officials are still investigating. But we've since learned that it's likely not the beef, but the onions that are probably the source of the contamination. 

In a statement over the weekend, McDonald's said that the slivered raw onions came from a Taylor farms facility in Colorado Springs. They were distributed to 900 restaurants in 12 states. They also said that they had removed all of those slivered onions produced from this facility as of October 22. And they're going to stop sourcing onions from that facility indefinitely. 

Onions have since been recalled in many of the affected states. And we've seen other fast food chains like Taco Bell, KFC, Pizza Hut and Burger King decide to stop offering onions at some locations, really as a precautionary measure. There's an NPR article earlier in the week that said that the chain plans to resume serving its Quarter Pounder minus the onions this week. 

Unger:  Andrea, what do we know about the people who got sick? And do we expect more? You mentioned they had removed those slivered onions from the menu, so to speak. Any more news on that front? 

Garcia: Well, according to the CDC, those reporting illnesses between September 27 and October 10 range in age from 13 to 88 years old. At least 22 people have been hospitalized, including two who have developed a serious condition that can cause kidney failure. One person in Colorado who was an older adult with underlying conditions has died. 

Unfortunately, we do expect there to be more cases. Many people recover without medical care and they're not tested for E. coli. We also know it takes three to four weeks to determine whether a sick person is part of an outbreak. So the CDC has characterized that continued risk to the public as very low. 

However, this does highlight a much larger ongoing problem and the difficulty of keeping fresh produce free from contamination. Unlike with meat, you can't cook away bacteria in fresh produce. Some experts have said that they typically avoid common bacterial culprits, including sprouts or bagged salad greens and even cantaloupe, to avoid getting sick. 

I think the bottom line, the more food is handled and processed on its journey from a farm to a restaurant or grocery store, the more opportunities there are to introduce and spread bacteria. That includes slicing, pre-washing or adding ingredients. So there's certainly more work to be done in food safety and in preventing foodborne illness. 

Unger:  All right. And we'll continue to watch as we look for developments on that into the holidays. Now that wraps up this week's episode. As always, Andrea, thank you so much for being here and sharing the news and your perspective. 

If you found this discussion valuable, you can support more programming like it by becoming an AMA member at ama-assn.org/join. You can always find all our videos and podcasts at ama-assn.org/podcasts. Thanks for joining us today. Please take care. 


Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.

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