Transcript of Get Ready Report podcast, episode 48: Summertime food safety

This is APHA’s Get Ready Report, coming to you from Washington D.C. Welcome. Today, we speak with Dr. Glenn Morris, director of the Emerging Pathogens Institute at the University of Florida.

How are you doing today Dr. Morris?

Just fine, thank you.

Wonderful. Thanks again for taking some time to speak with us. Our first question is, what is foodborne illness?

OK. Well, the most basic definition is that it’s illness caused by food. But there are a lot of different things that can cause illness in association with food. Sometimes it’s due to a bacteria or virus, what we call pathogens, that are present in the food that, that cause an infection and make people sick.

Sometimes it can also be due to toxins, or poisons or chemicals which are present in food — for example, the toxins that are produced by botulism. These tend to be much less common. So when we talk about foodborne illness, the main thing we’re thinking about, or the primary area of concern, are the bacteria or viruses present in food that cause an infection.

What are the most important causes of foodborne illness, you would say?

Well, a couple of years ago, in collaboration with the Robert Wood Johnson Foundation, we went through and analyzed all the available data to identify what we called the top 10 food pathogen combinations which had the greatest public health impact. Interestingly, No. 1 on the list was bacteria called campylobacter, that is commonly found on the surface of raw chicken. We estimated that is was responsible for some 600,000 illnesses per year here in the United States, costing some $1.2 billion, which is a not insignificant amount. As I said, campylobacter is found on the surface of chicken, and if it is present and the chicken is not well enough cooked, it can cause illness.

Following close behind was salmonella, which is probably a little better known than campylobacter. It’s also present on poultry, but you can also find it in eggs, sometimes on produce and in a variety of other foods. A third major pathogen of concern is what we call enterohemorrhagic E. coli. This includes the E. coli 0157H7, and for E. coli 0157H7, hamburger and produce are the major concerns, with close to 200,000 illnesses per year here in the U.S.

Now the list can go on and on, there are a large number of bacteria and viruses that cause infections that are transmitted by food. But those are sort of the ones that I’d like to focus a little bit more on today, because those are among the three worst actors if you will, among the different causes of foodborne illness.

Definitely. The next question is a two-part question, what foodborne illnesses occur more commonly during the summer, and how can people avoid them?

Well, the thing that characterizes summer is that it’s hot, and I’m not sure where you live, but at least here in Florida, it gets real hot.

So the thing about bacteria — and this is really not true for the viruses that cause illness — but bacteria might like a nice warm environment. And when bacteria are hot, they grow, and when they grow, they increase the likelihood that they are going to be able to increase illness. And so during summer, if any of the bacteria that I’ve just been talking about are present in or on food, and the food is allowed to sit at warm temperatures for several hours, the bacteria grow. And so the real key about summer is that one needs to be particularly careful, particularly for the bacteria you know such as campylobacter or salmonella or E. coli 0157H7, and keep them from outside the danger zone where bacteria grow.

So it goes back to sort of the old adage, “Keep cold foods cold and hot foods hot.” You need to keep them either at refrigerated temperatures where the cold keeps them from growing, or they need to be up above about 140 degrees, where it’s really too warm for their taste, and where you don’t get the sort of growth you’d get in the intermediate temperatures. So, again, the key to thinking about summer is that nice warm temperature, great to be outdoors, barbequing, but when you do that, make sure that your food is not also very happy about the temperatures right at that nice warm range. Keep it either cold or keep it hot to keep those bacteria from multiplying.

Awesome, so as a follow-up, what are some food safety tips for families who are looking to have a cookout this summer?

OK, there’re a couple of things to keep in mind. And again these are recommendations that come from CDC and FDA as well. One thing is wash your hands. You know, this seems very basic, but a lot of the pathogens that can get onto or into foods, are carried by hands. So you know, always wash your hands before you prepare food.

You need to keep raw food separate from cooked food. Now, a lot of things that come through our supermarkets that come to us that are raw contain bacteria on the surface. And I’ve already mentioned a couple of them. Campylobacter and salmonella are not uncommon on the surface of chicken, particularly campylobacter. So when you get that package of chicken legs off the supermarket shelf, there’s a possibility that those chicken legs may be carrying along some bad bacteria.

So raw foods can carry bacteria, again in part that result from contamination of the surface of the food, during the slaughter process. When you cook that raw meat, you kill the bacteria that are on the surface. And so consequently, raw meat is OK because you’re going to cook it. The problem is the potato salad that’s sitting over there on the side that you’re not going to cook again. And so if you manage to get drippings from that raw meat, which may have some of these bacteria, over and get mixed up with the potato salad, you could run into some real problems. And so you really need to be careful, again, particularly in the summer when bacteria like to grow, to keep raw foods separate from cooked foods.

Now sort of a variant on this is that when you’re marinating raw meat, again, keep in mind that raw meat may have bad bacteria on it, and if you marinate it at a nice warm temperature, you’re letting those bacteria lose in a swimming pool of very pleasant material and they’re going to grow like crazy. So when you marinate, always marinate food in the refrigerator, not out on the counter.

When you are cooking, make sure you cook things thoroughly. Again, when you cook it, you kill the bacteria, but if you don’t cook it enough, you could run into problems. And basically what that means is that ideally you should be using a meat thermometer. Hamburgers should be cooked to 160 degrees Fahrenheit, or cooked all the way through, and chicken should be cooked to at least 165 degrees.

Again, if you partially cook food in a microwave oven or stove to reduce the grilling time, do it right before the food goes on the hot grill, because you want to make sure you get to the right temperature, particularly inside the meat, so that you kill any bacteria that may be present. And, finally, refrigerate and freeze food promptly. You know there’re always leftovers when you’re out barbequing, well not always but if there are leftovers don’t let them sit around, because there again the bacteria can grow. So, once you’re done, make sure things go back on ice and/or into the freezer, so that you don’t get growth of bacteria.

So you talked a little bit about keeping raw food separate from cooked food. How frequently should families replace or sterilize their cutting boards? And should you have dedicated cutting boards for meat, fish, poultry, vegetables, etc.?

Cutting boards are a problem. As I said one of the major causes of foodborne illness is inadvertent transfer of bad bacteria from raw food, into food that’s already cooked, and that will not be cooked again. And cutting boards are frequently a place where that transfer can occur.

Let’s say you’ve cut a chicken up on a cutting board, and then you proceed to cut up potatoes, the cooked potatoes for your potato salad. Those juices that were on your chicken that contain these bad bacteria such as salmonella and campylobacter can definitely get onto the potatoes. You then let the potatoes sit on the picnic table outside, those bacteria are going to go nuts growing, and you’re going to have a big problem.

So I think that to be safe, one at least has to have two separate cutting boards, one for raw foods, and one for cooked foods or produce or basically things that you’re not going to cook further. Because you really don’t want to take any chance with something that’s not going to be cooked further; it’s going to be contaminated by some of the bad bacteria from raw foods.

Now, once you’ve used the cutting board, wash it off with soap and water, and you should be OK, unless the cutting board is starting to get cracks in it, or deep crevices. And so I’m not sure I’d say there’s a definite time when your cutting board has to be discarded, but if you’re starting to notice nooks and crannies in the cutting board, particularly wooden cutting boards, where bacteria might hide, probably not a bad idea to go ahead and throw away that cutting board and get a new one. If you think there’s a possibility that you’re not going to be able to get it really thoroughly cleaned with a good hot, sudsy water rinse.

Would you say that eating medium-rare meat is a safety hazard?

Medium-rare meat, particularly if you’re talking beef, is something that is of concern. In particular because of E. coli, particularly E. coli 0157H7, which for your listeners who maybe a little older, were responsible for the problems associated back in the 1990s with the big outbreaks in Jack in the Box, and still show up as problems associated with hamburger. Again, E. coli 0157H7 lives in the intestinal tract of cattle, where it’s very happy and does no harm.

The problem is that when cattle are slaughtered, that bacteria that’s present in the intestinal tract can get onto the surface of the meat. Now for a steak, if you stop and think, a steak is just kind of a cow’s muscle, and the inside of a steak is sterile. Bacteria can’t get into the inside of the steak, and so consequently we can eat steaks rare or medium-rare. We sear them on the outside to kill the bacteria that may be on the surface. But there’re really no bacteria inside to cause a problem.

However, if you grind that steak up, what happens? You take the bacteria that are on the outside, and you mix them together, so now those bacteria are on the inside as well. And we sort of have this mindset, “I can eat a steak rare,” but you really can’t or shouldn’t eat a hamburger rare, because now all of a sudden, the meat that’s in the center that’s not getting cooked, that’s still red, that’s going to have bacteria because you’ve ground it all up, and mixed what’s on the surface, and mixed it so that it’s in the middle. The same thing applies when you use those hammers to tenderize steak. Basically, anything that introduces bacteria in the center of steak or meat, or a hamburger, you really need to have it done or well done. Or use a meat thermometer, again, up to at least 160 degrees.

Now, sometimes it’s tricky to tell whether or not you’ve really gotten it hot enough inside to kill all of those bacteria, which is why meat thermometers are the best way to go. But to be perfectly honest, not that many people carry around a meat thermometer. Although, for people like myself who do this for a living, you know one sort of wished everyone had a meat thermometer in their back pocket.

But nonetheless, the best thing you can do is just to make sure that it’s done all the way through. You don’t have you know, rare or medium-rare because even though the risk is small, there is a risk that some of these E. coli 0157H7 bacteria could have been mixed into the middle of the hamburger and could indeed cause illness.

So what I heard was there’s somewhat of a difference between eating a steak medium-rare versus a hamburger where the meat was previously grinded up?

That’s correct. And that’s what most people don’t realize. They think, “Meat,” you know, “I can eat it rare!” And again, steaks are fine. But if you’re going to mix what’s on the top of the steak into what’s in the middle by grinding it up, then all bets are off, and you’ve introduced bacteria into the middle, and you really do need to cook it.

Yeah, definitely. That was super informational. Now how about foods that include raw fish, such as sushi? Are those safe to eat?

Eh, you know, sushi get a bad rap. The reality is when you look at numbers there’re not that many problems with sushi. Now if the raw fish is not properly handled, not kept appropriately chilled, you can run into problems with spoilage bacteria. And you may not want to eat it. But in reality, we don’t see that much of a problem with foodborne pathogens. Things like campylobacter, salmonella, E. coli. Those tend to be beef and chicken. So yes, I’d definitely be careful with sushi, keep it cold, keep that fish cold, but in reality you’ve probably got greater risk from things like chicken and beef.

Oh, OK. So for our last question, what are symptoms that might be expected in association with a summertime outbreak of foodborne illness, and when should you see a doctor?

The main symptoms that you’re going to get with foodborne illness are diarrhea, abdominal pain and vomiting. Your standard, you know, threesome for things like with salmonella and campylobacter. For relatively mild illness, you don’t really need to see a doctor. The main concern is dehydration.

You want to make sure you’re getting plenty of fluids, and in some cases, drinking things like Gatorade or Pedialyte may be a good idea because those contain not just the fluid but also the electrolytes, to keep your body from getting dried out. And again if you’re having a couple of episodes a day, might not hurt to add some Gatorade or some Pedialyte. If your symptoms go on for more than a day or so, or severe, or particularly if you’ve got bloody diarrhea, definitely go see a doctor. If your diarrhea is getting worse, if it’s not getting better after a couple of days, again, I’d recommend that you go see a doctor.

Well Dr. Morris, this has been a very educational talk, not only for me but it will be for our listeners as well. Thank you so much for speaking with APHA.

You’re quite welcome.

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Posted July 31, 2017. Listen to this podcast on our main podcast page.