Think Out Loud

Virulent strain of salmonella spreads through U.S. food supply

By Elizabeth Castillo (OPB)
Nov. 29, 2021 6:24 p.m. Updated: Nov. 29, 2021 9:55 p.m.

Broadcast: Monday, Nov. 29

A once rare strain of salmonella found in poultry has spread largely unchecked, according to reporting by ProPublica. The strain, multidrug-resistant infantis, can send victims to the hospital and is resistant to many of the drugs used to combat food poisoning. We hear from two of the reporters who worked on the story. Michael Grabell is a ProPublica reporter and Irena Hwang is a data reporter with the organization.

THANKS TO OUR SPONSOR:


The following transcript was created by a computer and edited by a volunteer:

Dave Miller: This is Think Out Loud on OPB, I’m Dave Miller. We start today with salmonella. It hospitalizes and kills more Americans every year than any other foodborne pathogen. It’s found most often in chicken, which Americans are eating more and more of. And despite the fact that a particularly dangerous variant of salmonella is being found in poultry farms, processing plants, and poultry products around the country, federal food safety authorities are doing very little to respond to it. That’s one of the takeaways from a major recent investigation by a team of journalists at ProPublica. Those journalists join me now. Michael Grabell is a reporter, Irena Hwang is a data reporter. Welcome to you both.

Michael Grabell: Thanks for having us on to talk about this.

Irena Hwang: Glad to be here.

Miller: Michael first, can you tell us about this outbreak that was first really detected in 2018, and as you note, is absolutely still going on?

Grabell: Yeah. So this is an outbreak of a strain of salmonella called “multidrug resistant Infantis.” And the CDC opened an outbreak investigation in 2018 after they started noticing an uptick in these cases, and very quickly discovered that this wasn’t tied to a single product that you pick up at the store or a single event, like a potluck dinner or a restaurant. This was widespread throughout the chicken industry, affecting lots of different brands, lots of different types of type of chicken, ground chicken, chicken parts.

And what’s so alarming about it is that it’s resistant to about four of the five main drugs that doctors typically will prescribe when someone gets severe food poisoning. So if you get sick from the strain, it’s very likely that the first drug that the doctor prescribes is not going to work.

Miller: What are the potential effects of salmonella?

Grabell: So salmonella, we often think of it as like you get a few days of stomach pain. But it can be a lot worse than that. It’s vomiting, it’s diarrhea, it’s fever, it’s chills. It can cause long term consequences to your gastrointestinal system, as well as there have been some long term consequences noted with a severe form of arthritis.

Miller: What did federal investigators do in response starting in 2018?

Grabell: So they opened an investigation like they typically do. The CDC opened an investigation and tried to gather as much information as they could. But one of the problems is that the CDC depends on the USDA to respond and regulate. The CDC does the investigation, but the USDA is the one who would initiate recalls. But there’s two main problems: the CDC does not have the authority to actually order recalls. They can only request a recall. Salmonella is allowed in raw chicken under the assumption that people will cook it appropriately and not cross-contaminate their kitchen, which has been shown to be a problem over and over and over again. But because of that, the USDA is frequently finding this exact strain of Infantis in poultry plants today. And public health authorities are also going out to grocery stores and finding it on store shelves. But they have no authority to go and pull that off the shelves, so it remains in the chicken that’s being sold in supermarkets and restaurants.

Miller: What happens when the USDA requests that a processor or retailer voluntarily remove products from shelves, or not send it to grocery stores to begin with? As you’ve noted, they have no power to compel these companies to do so. All they can do is ask. What happens when they ask?

Grabell: When they aske they generally do get compliance. And usually before that, the CDC or the media or somebody has already announced whose product it is that has the problem. The problem here is that it’s essentially in every product. I clarify that to say it’s not every piece of chicken that you buy, but it doesn’t affect one brand, one product. So what do you recall? Do you recall all chicken and say it’s too much of a risk? That’s sort of what the USDA has said, is that it can’t recall or request a recall of all chicken. To pinpoint one brand wouldn’t just solve the problem.

The second problem though is that this is not coming from Tyson or Perdue or any other specific chicken company. This is coming from above them, at the farm level. And potentially at the few companies that breed the nation’s chickens. So it’s passing pretty broadly throughout the poultry system. And the USDA has no authority to regulate the safety of food on farms. They are focused primarily on meat and poultry that’s produced at slaughterhouses and processing plants. And their authority does not allow them to really go above that, even when they know that the strain of salmonella is spreading on the farm.

Miller: So Irena Hwang, let’s turn to you. As I noted, you’re a data journalist with a background in complex analysis of a lot of data, including genetic data. Can you explain what you did to find out basically how both food safety officials and the poultry industry allowed this Infantis strain or family of strains to spread?

Hwang: Sure. So the core of our analysis was two or three different sources of data. The first was just publicly available data about genetic sequencing. This is hosted through something called the Pathogen Detection Project, which is organized by the National Center for Biotechnology Information. And this is a centralized repository of a bunch of different salmonella and other foodborne pathogen testing results, either from patients who have come into the hospital for food poisoning, or from inspections at food processing centers, or even samples taken from packages at grocery stores.

THANKS TO OUR SPONSOR:

The other set of data that we really relied on were from public information requests about patient information that was taken during the outbreak itself, and also more detailed information about food safety inspections. By combining this information, we were able to better understand how the CDC and other agencies were tracking the spread of this bacteria, because we got information about time and also location. But most importantly, we were getting detailed information about how genetically similar all of these different bacterial samples were to one another.

Miller: Were you, in a sense, copying work done by federal authorities, either at the CDC or the USDA? Or were you doing original research?

Hwang: That’s a really good question. I cannot speak for the CDC in terms of what they have done. My understanding is, in some sense, the analysis I did did help me understand exactly all the information they had at hand, and helped all of us better understand how they’re making these decisions. And the conclusion was that the data was showing that this was a different type of outbreak that is becoming more common, and used to be fairly uncommon. And it’s more difficult to deal with in the food supply. And so I would say that helped give us a better understanding of what they were confronting. And as far as novel research, I think we’ll have to save that for another story.

Miller: Well I guess the reason I asked the question is because this seems like clever, enterprising work on the part of a data driven investigative journalist. But it also seems like the kind of work that I want federal authorities and regulators, if they’re actually focused on consumer safety, I want them to do this. I don’t want this to have to be the work done by journalists. Could they use the kind of detective work that you’re talking about, looking at genetic sequences and tracing actual illnesses to more specifically with more granular detail to places where the chicken came from? What could they do with that data?

Hwang: Well, we do know that they are doing a fair bit. They are monitoring how similar all of these bacteria are to one another through not only data repositories like the Pathogen Detection Project I mentioned earlier, but also programs like PulseNet, which integrate information from local state public health agencies about individual food poisoning cases. They are also developing new ways of integrating the latest technology into their protocols. I know that recently, a couple days before we published our investigation, the USDA announced that the agency was rethinking its approach to salmonella, and specifically said that they would be trying to tackle it, but they were a bit vague on details. And the last thing I will mention is that we do know that they are working closely with academics and other research agencies to make the best use of this new data.

Miller: Michael Grabell, if I understand this correctly, the USDA is saying, “We’re actually going to take a different approach to salmonella.” It does seem like that’s a direct response, maybe belatedly though, to your reporting. Is that how you see it?

Grabell: It’s hard to say. We know that we have been asking for interviews about this very topic for weeks leading up to this. But we also know that consumer groups have been raising this issue as well, and complaining about how the USDA regulates salmonella. About a week before our publication, they announced that they were gonna be rethinking the approach and trying some things. But right now, all we know is that they are looking at pilot projects and things like roundtable discussions with stakeholders, industry, consumer groups, and things like that. Some people we spoke with criticize that approach, and say we know what the problem is. Number one, we’re allowing contaminated poultry to be sold. Number two, we’re not focusing on the types and the amount of salmonella that commonly make people sick. And number three, the USDA does very little testing to begin with. I think in our story, we figured out that there’s about 80 samples of raw poultry taken a day. But in the course of a day, those plants across the country will be slaughtering 300,000 chickens and turkeys in a day. 80 out of 300,000 is a very small fraction.

Miller: And then and among those 300,000, you can imagine how many products that’s going to turn into. As you know, we are often talking about ground chicken, which may have many, many different chickens that make it up, or chicken parts. What did you actually hear from experts about what a better food safety system would look like with respect to salmonella?

Grabell: One of the key things we heard, that a lot of European countries do, they have “from farm to fork,” is what they call it. And they actually start by looking at practices on the farm that can reduce salmonella, whether that’s mandating vaccines for the types of salmonella that are most risky for public health. Some countries go as far as actually depopulating or slaughtering flocks that contain really dangerous strains of salmonella, particularly the breeders, because that can spread so far throughout the food system.

One striking thing we learned is that one of the common ways that salmonella spreads at the farm is through poultry litter. You imagine a barn. These are often very crowded conditions. In other countries, after every flock, they will replace the poultry litter, which is the stuff, the waste and the stuff they sit on all day long, and clean the barn, or clean the chicken house. In the US, that’s not the case. It’s sort of treated and heated in the hopes that it would eliminate the salmonella. And then they bring in the new flock into the same poultry letter. Basically the same sawdust and waste that was used for the previous flock. So that’s one way that the US is different.

Miller: So that’s when the chickens are alive. But throughout your article, especially in the chicken processing plants, you show how, step after step, there are aspects of the hugely industrialized, very efficient, (and probably because of that, leading to relatively inexpensive meat for many Americans,) mechanized system that that makes salmonella more likely to spread, and less likely to be fully eradicated. And then there are questions about individual responsibility, when it actually gets into people’s homes and people’s countertops.

But I’m curious, when it comes to the industrial production here, how much of this, in your mind, boils down to the fact that industry has prevented regulators from actually putting into place meaningful consumer protection?

Grabell: Obviously, we know agriculture and the meat and poultry industry has a lot of power within the USDA. And the USDA has this dual mission. A small part is public health, but their larger mission is to promote agriculture. So it’s always sort of been an area of conflict. What we see within the processing plants is that there is a lot of opportunity for cross contamination. And it’s why things like ground chicken have more contamination than a whole bird. Because it’s not just one chicken at that point.

One thing we saw over the past 25 years is that we have not reduced the number of salmonella illnesses in the country. The industry, however, has reduced the amount of salmonella found on chicken. And that’s because there’s been an introduction of chemicals to decontaminate the chicken in the processing plant. So we created this app at ProPublica called the chicken checker, which you can find by going to propublica.org/chicken. And you can actually look up the brand of poultry and the plant that your poultry was processed at, and determine for yourself how safe you feel. It will give you the track record of the plant when it comes to salmonella.

Miller: Well, let me ask Irena about that. I went onto it, to look at various Northwest producers, one of the ones that I’ve seen most often around here and I think it may be distributed nationally, is Foster Farms. It’s in Washington state. And when I looked at the data that you all put together, I saw that 6.8% of 59 samples of chicken parts had high risk salmonella. That’s above the national average for that category, but it’s not the highest. I’m not sure what I’m supposed to do, as a potential consumer, with that information.

Hwang: That’s a great question, and one that I recently had to ask myself when, three weeks ago, I was preparing a little chicken, a little cornish hen in my kitchen, and thought, huh, I should check this before I cook it. I had just tossed it onto my stove, pulled up the app, and found that a full 60% of samples from that processing plant had not only salmonella in them, but actually had the salmonella strain Infantis that we’ve been researching.

Miller: So what did you do?

Hwang: Yeah, that was a bit of a rude surprise. Honestly, I cooked it. I made sure I cooked it thoroughly to 165°F and above, which is the temperature at which salmonella dies. I made sure to wash my hands. I immediately sprayed down my sink and cutting board with disinfectant spray, tossed the cutting board into my dishwasher and immediately ran a cycle.

When it comes to bacterial pathogens in food, the name of the game is going to be just being as safe as you can. I don’t think that the normal consumer needs to be frightened necessarily. They do need to be careful, and they do need to be smart. And the good thing is that by being smart, you can avoid possible contamination. So I think that this is a great time to remind consumers that you want to be cooking your meat to a safe temperature. You want to be aware that different meats cook at different rates, different thicknesses cook at different rates. So you’re gonna be wanting to use a meat thermometer, not only at different parts of a chicken. Even if you have one uniform boneless, skinless breast, you’re going to be wanting to check the thick part and the thin part. But also constantly wash your hands, avoid cross contamination. Be smart about not using the same cutting board or surfaces for raw meat as cooked products and vegetables. You know, we got to do what we gotta do.

Contact “Think Out Loud®”

If you’d like to comment on any of the topics in this show, or suggest a topic of your own, please get in touch with us on Facebook or Twitter, send an email to thinkoutloud@opb.org, or you can leave a voicemail for us at 503-293-1983. The call-in phone number during the noon hour is 888-665-5865.

THANKS TO OUR SPONSOR:
THANKS TO OUR SPONSOR: