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Welcome to The Exposure Scientist Podcast. As summer heats up across much of the United States, it’s the season when Legionella bacteria and Legionnaires’ disease once again become pressing concerns. The conversation focused on understanding the resurgence of these risks, the challenges around tracking outbreaks, and why official data often lags behind real-world occurrences. One concept discussed was how artificial intelligence and news aggregation can supplement traditional reporting, offering more timely insights for those managing water systems. A key theme that emerged was the need for proactive, well-informed water management plans—moving beyond simple box-checking to truly mitigate risk. The discussion explored lessons from recent outbreaks, the importance of third-party verification, and encouraged audience engagement from anyone with experience in managing or investigating Legionnaires’ disease events. Join us as we blend scientific context, practical risk management, and emerging technology to shed light on the hidden hazards in summer water systems.
Contact Dr. Alex LeBeau at Exposure Consulting for exposure litigation support or Exposure Science Consulting.
[00:00:00] You might not realize it, but we are exposed to dozens of hazards every day. Can any of these hazards negatively impact your health? Definitely. This is The Exposure Scientist Podcast. My name is Alex LeBeau, and here we answer your questions and concerns on what you may be exposed to every day. Welcome to The Exposure Scientist Podcast.
[00:00:29] Hello and welcome to today's edition of The Exposure Scientist Podcast. It's summer, and it's that perfect time of year where things are getting warmer in much of the United States and the time of year where Legionella and Legionnaires Disease starts to, I'll say, proliferate again when we should be keeping an eye out for the occurrence of Legionnaires Disease
[00:00:55] and ensuring that our water management plans are adequate for at least understanding the risks that we are attempting to manage with those plans. I thought one bit of information and pieces of information, I've covered this on past podcasts and in some information I've presented on the tracking, I'll say, of cases or occurrences of Legionnaires Disease and how it's hard to track those.
[00:01:25] You know, we have weekly updates. We have some states that have data that's more easily or readily available. We have the CDC weekly updates, past iterations of those. For annual numbers, those take a lot of time for the CDC to update. I'm going to illustrate some of that information today. But I think it's interesting. This is kind of a discussion of not only Legionnaires Disease, but the use of, I'll say, AI for kind of understanding where risks may be.
[00:01:55] I think it's important to understand and let's contextualize for Legionella and Legionnaires Disease risk that oftentimes the majority of occurrences of Legionnaires Disease are individual cases. Let's refresh on what a outbreak is. An outbreak is typically defined as two or more individuals associated with one particular facility over a certain period of time. In some areas, it could be six months. In some areas, it could be 12 months.
[00:02:26] Most of the time, they're just one-off cases. You'll see a case of this here, a case of it there. They typically are not outbreak scenarios. But I thought it'd be interesting to kind of get an idea of what outbreaks have occurred within the last few years. Again, there's no, if you go on the Morbidity and Mortality Weekly Reports, MMWR from CDC and look up Legionnaires Disease,
[00:02:51] it takes a lot of, I'll say, work to get there for publication in those. And I am astounded by some of the information I've seen as far as probably why it takes so long to get there. And I'm not going to mention the particular one or the particular individuals. But, for example, this is, there's one, I'm going to tie this in a little later.
[00:03:18] There's one MMWR associated with Legionella or Legionnaires Disease outbreak from 2022. On this article, there are approximately 30 authors. 30 people was required to review this, write this, investigate it. There's a lot of stuff that goes into this.
[00:03:41] And that's probably why it takes so long to get this information out there is because it's got to go through so many eyes, go through so many iterations. In my opinion, that's a lot of unnecessary information. You could maybe look at AI and say, okay, let's use AI. Let's use news articles. Let's see what's going on. Let's see information, as we say, from the field. So what I did was I challenged this particular instance. I'm using ChatGPT.
[00:04:11] ChatGPT, I said, you know, generally, and I did two prompts here, and I thought it was interesting. And what this is telling me, and I'll tell you here in a moment, is the prompt is even going to depend on how your results come out. So, for example, I said, you know, give me the five, I'm sorry, the first one, I said, give me the three largest or biggest Legionnaires disease outbreak events for the past five years and list them in the order of cases. Well, when I first did that, it gave me from around the world.
[00:04:40] I was like, okay, well, let me refine my search. Let me say domestically, you're from the United States. So it gave me, I'll just say, I did three here. The first three, it said, was from Harlem in New York City in 2025. It said there were 114 cases. The second from ChatGPT, it said Marshall County, Iowa from 2025. That was 74 cases. And Grand Rapids, Minnesota from 2023. There were 34 cases.
[00:05:08] So I gave another prompt. I said, you know, what are the biggest five domestic Legionnaires disease outbreak events in the past five years and list them in order of number of cases and deaths associated with outbreaks. Very similar search. This left off some results and gave me other ones. So this is kind of an illustration of AI could be useful in some regards, but it still requires everyone to do their due diligence.
[00:05:38] Here it discusses Harlem outbreak. Again, 14 cases, seven deaths. Napa County, which is in Napa, California. 17 cases. This one talked about Amsterdam nursing home in Manhattan. Eight cases. There were other ones that were associated that aren't even mentioned here. Some I have particular knowledge of.
[00:06:01] So you're not going to get all the information readily available that you may need to. And this goes back to the presentations that I've given. This goes back to the information that I've looked at. You're not going to know outbreaks until it's much later on. In fact, this one particular one from CDC. From a 2022 outbreak was not published until the end of 2023. Actually, the event was July.
[00:06:31] This claims July 2022 from Napa, California. And this was not published until December of 2023. A year and a half. That's not helpful for anyone, any practitioner in the field. Again, looking at weekly data, you kind of get an understanding of where things are as far as states. As far as generally just as states. But again, that's not always up to date. That's always being updated after the fact.
[00:07:01] And getting annual numbers takes years to get out. So looking at news stories may be a good way. You know, I have a news aggregate that send me information daily on Legionella and Legionnaire's disease. Just kind of see what's going on. Just see what's in the news. See where cases may be. Because that's the best, most up-to-date information. You can use ChatGPT. But, or any other AI. Again, I say any other AI. I haven't tested anything else.
[00:07:29] But I think it's important to say, listen, you know, there's useful information here. You may have to do a few searches to kind of figure out what's going on and get the background information. But this is certainly, your research and your knowledge and your understanding is certainly going to be more up-to-date than what CDC publishes in MMWRs or on their weekly reports. And again, as we've discussed, many of these cases are just cases.
[00:07:58] They're not associated with outbreaks. And there's a document, I think, from CDC from a few years ago, two years ago, that discusses an investigation of outbreaks for the past 10 or 15 years. And, you know, it's a very small number of outbreaks as compared to the annual number of Legionnaire and Legionnaire disease cases that are in the thousands. So that's important context.
[00:08:22] But what I'm doing and wanted to highlight here, at least in this introductory one, because what we're going to do, we're going to get into these a little more. We're going to at least, based on the information that's available publicly, as far as we can say, it may be, you know, news releases from local health departments. It may be local news stories. It's kind of a, take a look at these matters. See what's going on. See what the putative source was.
[00:08:51] See if the information that's available kind of points to that source. See if there's alternative potential sources that were not investigated and why they're not investigated. And I can tell you in many of these instances that, you know, I've seen these particular ones that we're going to get into, but other ones that were sources that were completely just written off and didn't make any sense.
[00:09:11] But I think this is at least important for when you're getting ready for your water management plan, when you're kind of understanding, okay, what is my plan? Have I checked the, you know, what have I done for my plan lately? There's lots of box checking that can go in these water management plans.
[00:09:34] I think that you need to make sure that it's more than just a box checking exercise when you're managing risk or attempting to manage risk. And explaining that to your folks on the ground, using this information to say, okay, well, there are cases, there are outbreaks, there are some deaths. Where are we seeing this? What are the causes? What information do I have available for understanding what these, where these cases are?
[00:10:03] Or maybe getting into, again, as I get into the analysis, what were the boots on the ground, so to speak, saying that there were deficiencies in. Use the information where these deficiencies were observed in these cases, these outbreaks, to apply to your facility to make sure that you're managing risk as best you can.
[00:10:27] Again, there's no such thing as zero risk. The only time there's zero risk is when there's zero life. I mean, let's just be honest. You know, there's always going to be some level of risk. This is more of a qualitative high, medium, and low. What low risk are we looking at? Can we reduce things from a high risk to a low risk or minimum or negligible risk?
[00:10:53] How are we managing the risk in our facilities using the information that's available, using prior experience? Because, you know, I've seen it said at other conferences and say, well, the science on Legionella has settled. Or if it were settled, then we wouldn't still be having outbreaks. But we're still having outbreaks. We're still having cases. Again, 2025, there are a number of them.
[00:11:20] So, this is going to be a series that we're going to get into that kind of discusses it, puts it in context, but highlights it, too. As it's getting hot again. We know what happens every time it gets warm outside, every time the seasons change, every time that summer comes around and more people are using the equipment. And there are always problems with making sure the equipment's maintained properly.
[00:11:50] Do you have, are you verifying that the people who are doing what they're supposed to be doing are actually doing it? You know, I find that as, you know, there's nothing wrong with having third-party verification. I've seen it plenty of times. And I think it's worthwhile saying, okay, let someone third-party come in and verify that these people are doing what they're supposed to be doing. Are they managing our risk appropriately? What else could they be doing?
[00:12:13] Are they holding up their end of the bargain, so to speak, of making sure that our facilities are complying with what's on our water management plan or even their contractors? There's something to contract me like, yeah, you know, even though they say that they're doing stuff for us, are they putting the risk? Is there information of the contract they have with us? I'm not a contract guy, but I can at least read the plain text and say, are they putting the risk back on us saying, well, we're helping you with this, but we're not actually managing the risk. That's still up to you.
[00:12:42] Because a lot of times people say, oh, yeah, we're going to help you manage the risk. But when it comes down to it, they may be helping you manage it, but they are not taking the responsibility for managing that risk. And that is important. There's distinctions there that just because they are there on your behalf doesn't mean they're taking the responsibility that you have.
[00:13:05] And it may be, well, you know, they're not, you know, you may not be the experts, but I'll say the general consensus is then you should be getting someone who is that expertise to help you, give you that guidance, give you that third party oversight. So we're going to look at these outbreaks and some coming up episodes, take a look and see where there may be some room for improvement, not only from the management side of water, but from the investigative side of the outbreak. Was something missed? Was something overlooked?
[00:13:34] There are other potential sources. This is going to be fun. If you have any comments or have any participation in any of the outbreaks that have occurred or any feedback you want to give, please feel free to reach out. Or if you want to come on, if you've been involved in an outbreak and you have some unique, I'll say, perspective on it. Come on, let's have a discussion. Always up for chatting with people. This is today's episode, the Exposure Scientist podcast. Hope you're doing well. Hope to hear from you soon.
[00:14:02] And I look forward to speaking with you in the next one. Take care. Exposure Science covers a broad subject area, including toxicology, industrial hygiene and risk assessment. From occupational, community or environmental exposure, exposure scientists apply scientific methodologies to understand exposure risks and apply controls when necessary. We at Exposure Assessment Consulting have this expertise.
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