New data suggests that some of what we thought we knew about how Valley fever spreads isn’t actually true.
The study, published in Scientific Reports, is based on data collected from air filters installed in some of the nation’s largest cities after 9/11. These are intended to be used to monitor potential biothreat substances in the air, and while they are not detected, they are gathering information that scientists have not focused on before. Masu.
Dr. Dave Engelthaler is one such scientist. He is the director of the Division of Infectious Diseases at the Translational Genomics Research Institute (TGen) and joined the show to discuss this issue.
Pooja Gandhi/Centers for Disease Control and Prevention
Medical illustration of coccidioides, the fungus that causes valley fever (coccidioidomycosis).
Full interview
Dave, some of the information from these filters has to do with the fungus that causes Valley fever, and some of what you find perhaps seems a little counterintuitive?
Dave Engelthaler: Yes, that’s right. I wanted to be able to look at valley fever, where people are exposed to fungi in the air, and until now we haven’t really had that ability. And with these air filters, you can learn when Valley fever fungi, so-called cocci, appear in the air, where they appear, for how long, and what might be causing them. You can check if there is one. We believe this is critical to preventing cases in the future.
Yeah. So, based on this new information, what do we know about what causes cocci to become airborne?
Engelthaler: Well, I think we started building the story without having enough information beforehand. That included the idea that sandstorms and these haboobs were really important causes of Valley fever. And what we’re finding is that they’re not. In fact, it appears that there are actually no significant effects when people are exposed to Valley fever fungus. We also see that when fungal spores are suspended in the air, they are not evenly distributed. It is not always seen across the valley. You will see hotspots appear and disappear. And I think that’s probably the case, but it’s much more variable and much more localized than we originally thought.
Does it seem like there’s some rhyme or reason to where, when, and why these hotspots appear?
Engelthaler: Yes, I think what’s really important is to go back to the basic life cycle of this fungus. This means that fungi need to grow in specific locations in the soil. And that soil can become contaminated and disturbed, and the spores can get airborne, and then someone, or a dog or an animal, has to inhale it and continue the infectious life cycle. And someday we have to return to the soil. And what’s really important is that we know that the soil is not uniformly contaminated.
Therefore, the areas where the fungus is present in the soil should be disturbed. And we think that happens at a much more local level than, say, a giant sandstorm blowing through and pushing pollution and fungi into the air.
So, the key is, if we can find out where in the soil this fungus lives, whether it’s in this part of town, this site, or this part of the desert, then we can figure it out somehow. Is this the key to doing so? , could it help tell people not to go to an area at a certain time?
Engelthaler: Yeah, I think that’s a really important point, Mark, but we also want to make sure that wherever it is in the soil, it’s not going up into the air for humans to inhale. . What we know about soils is that they are highly variable. When the fungus appears, there may be a real hot spot in the soil. For example, where there were animal burrows. Perhaps animals have died from bacteria and contaminated the soil. But if you go just a few feet away and dig it up, you won’t find any fungus there.
Therefore, it is very patchy and variable in nature, with various distributions around endemic areas in the Southwest. We know that it actually occurs in the soil and surrounding desert throughout the Valley region. So when there is disruption, such as new construction or development, or even when people are just gardening in areas where the fungus was present, those spores can be lifted from the soil into the air and we can breathe them in. There is a gender.
I think this is what we’re seeing now. I suspect this highly localized impact is occurring perhaps 1,000 times a day in neighborhoods across the Valley. And, rather than saying that Phoenix’s air is widely contaminated, that you’ll be exposed to those spores by chance, that doesn’t seem to be the case at all.
Yeah. Well, is there a way to know if a particular patch of soil contains this fungus? Is there a way to detect it?
Engelthaler: It’s really difficult. And actually, it’s not easy to detect fungi in soil, but we can. And it probably doesn’t make sense to try to find all the locations. Because, as I said, what may exist in one location may not exist just a few feet away. So just doing random soil sampling probably won’t tell us much, but what we can probably do is do more soil sampling in areas where we know we’re going to disturb a lot of soil. That means new developments, upending agriculture, and so on. Field to the apartment. That might actually help, or at least be a better way to mitigate and prevent that soil from getting airborne, if that’s what’s going on.
We are already doing a lot of work on dust mitigation. We may need to do more based on the findings we have and the continued research we are conducting.
How much harder would that make your job trying to learn about this, perhaps trying to figure out where these spores exist and how they get airborne? Most people who have these spores in their bodies will never know. Do you experience Valley fever symptoms?
Engelthaler: That’s a really good point. We know there’s a lot of exposure going on. In fact, the CDC estimates that more than 300,000 people are infected each year in the Southwest, and the vast majority of those people don’t even know they’re infected. Maybe they just have a mild upper respiratory illness or respiratory illness, or maybe they have walking pneumonia. And some of that goes into the health care system, and some of that actually gets tested and turns out to have Valley fever. Therefore, we cannot understand valley fever just by looking at human cases. That’s really what we’ve been doing for the last 50 years, trying to understand this by just looking at what cases are showing up.
Now, what we have are tools to better observe it in our environment and see where it’s showing up. How does it work? What is causing it? So public health messaging and response efforts can lead to better, more targeted solutions.
Yeah. So let’s look at this new tool and maybe a little more accurate way to know where the cocci are. Given this information, what actions do you think public health officials and perhaps residents should take?
Engelthaler: As you know, we are working with local and state public health, the Centers for Disease Control, the National Weather Service and the Department of Homeland Security to better understand what this data tells us and how it can be used. We work closely together. Now we’re starting to map more closely to where we know people are infected. We’re also mapping in more detail, but we’re also using satellite imagery to see what’s happening in the surrounding area before and while the filters are positive, and to actually identify fungal outbreaks. This allows you to check again at a higher resolution what is causing this. into the air.
This is a moving target, and we finally actually have the tools to explore this in more detail.
