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Lesley McClurg: From KQED, welcome to Forum. I’m Lesley McClurg, in for Mina Kim.
A few years back, Lake Anza — this tiny swimming hole in the Berkeley Hills, near my house — closed because of a toxic algae bloom. It’s an event that’s going to become a lot more likely under a warming climate. The lake was fenced off, the water turned a thick, murky brown. It’s usually a lot of fun, buzzing with swimmers and families, but it was eerily quiet and pretty grim. Every warm day this summer, I get a little fear inside me. I worry it could happen again.
The impact of microbes — these tiny, tiny organisms — is very likely to change dramatically in coming years. In a new article for The New Yorker, Shayla Love explores what is happening to microscopic forms of life as the planet heats up. Shayla, welcome.
Shayla Love: Thanks so much for having me.
Lesley McClurg: You open your piece with a story about Vernon Spear — a big, burly eighty-five-year-old man with thinning gray hair who dipped his hand in a local river in Cambridge, Maryland, and got infected with Vibrio vulnificus, popularly known as flesh-eating bacteria. Tell us the story.
Shayla Love: Vernon lives on the Eastern Shore in Maryland, where he was born and has lived his whole life. One thing to know about that part of the country is that eating crab is a big part of the lifestyle. A lot of people have crab traps hanging off the docks near their homes, and Vernon is no exception. Almost daily in the summer, he’ll walk out to check if there are any crabs to steam and eat with Old Bay Seasoning, as you do in that region.
Last July, he got a couple of small scratches on his arm from the wire of the crab trap. He barely noticed — they drew a little blood, but they were tiny. He went inside, brought some crabs in. Then, over the course of the next day or two, his arm started turning a violent shade of red and purple and began to swell. It was a reaction to Vibrio vulnificus — commonly known as flesh-eating bacteria, though it doesn’t actually eat your flesh. What it does is cause the flesh to become necrotic and die. It’s a very dangerous infection: for roughly half the people whose infection reaches the bloodstream, it’s fatal.
Lesley McClurg: How did his case go?
Shayla Love: Vernon survived — he was very lucky. His local emergency room doctor recognized it right away, and he was sent to a larger hospital in Baltimore, the shock trauma center at the university there. There’s really no question about whether surgery is needed; the standard response is to cut out the dying flesh. Antibiotics can be used, but they’re not effective on their own. So large portions of his arm were excised, and then you just have to hope the infection hasn’t spread further.
He was fortunate to keep his life and his arm — a lot of people in his situation require amputation. And he was just shocked, because interacting with the water was something he had done almost every day of his life during warm seasons on the Eastern Shore. He’d had cuts before and never thought twice about it. He simply couldn’t believe this had happened to him.
Lesley McClurg: How common are these infections in Maryland?
Shayla Love: Vibrio vulnificus is quite rare. Flesh-eating bacteria is a terrifying name, and it is a terrifying infection, but these cases are still very uncommon. What’s changed is where they’re showing up. For most of Vernon’s life, seeing this infection north of Georgia was unusual. The concern isn’t that this is suddenly becoming common — it’s that the bacteria are appearing in more northerly climates. There have been infections as far north as New York and Rhode Island. The reason is that the water is getting warmer as the planet warms. The bacteria aren’t migrating so much as they’re proliferating in places where the water is now warm enough to support them. That’s what made Vernon’s case so striking — just how far north it occurred.
Lesley McClurg: Since most of our listeners are on the West Coast, should we be worried? Is this bacteria moving north on this side of the country too?
Shayla Love: Vibrio vulnificus exists in all brackish water — a mix of fresh and salt water. Its northward movement has been documented all around the world. There’s even been an infection north of the Arctic Circle near Finland, which is remarkable — that the water could be warm enough there to host a Vibrio population at levels sufficient to cause infection. So yes, it’s a global phenomenon. And if the water keeps getting warmer, the bacteria will keep expanding into new territory, because warm water is simply what it thrives in.
Lesley McClurg: Do we have a sense of how fast cases are increasing?
Shayla Love: Researchers in Maryland, where there’s some very good Vibrio research happening, have found that the number of cases increased by more than fifty percent over a span of fourteen years. The numbers are still small, but they are growing. What’s also concerning is that the Vibrio season itself is expanding — starting earlier and ending later. Right now this is more of a concern in Gulf Coast states like Florida and North Carolina, whose public health departments are well aware of these infections. But in states like Maryland, or farther north, people may not recognize the symptoms because they’ve never had to worry about it before. So even a small increase could lead to deaths simply because of lack of familiarity.
Lesley McClurg: Are there other microbes along the West Coast that may be changing because of climate change?
Shayla Love: One that comes to mind is actually a fungus — the one that causes valley fever. In California, it’s not only getting warmer, but the wet seasons are getting wetter and the dry seasons drier. These shifting conditions affect how the fungus behaves. It takes up residence in the lungs and can cause infection that way. When it’s very dry, it gets blown around more easily. But when it’s wetter, it grows more abundantly, and then once the dry season returns, it spreads through the air and people can inhale it. Valley fever is definitely a growing concern in California.
Lesley McClurg: Going back to Vernon Spear — you said he’s doing okay now. Any lingering effects, or is he more or less back to normal?
Shayla Love: He’s doing well. In October, I went and observed a follow-up surgery where they did a skin graft, removing skin from one of his legs to cover the wound left in his arm. That was the final step. He texted me a photo recently of how he’s healing — you can still tell something happened; the skin is pink and shiny — but he feels very lucky. He’s also heard from others in his area. Once you’ve had a flesh-eating bacteria infection, people tend to find you and tell you their stories. He’s been hearing about friends of friends, neighbors, fishermen — people who work on the water, get cuts, and have had similar infections. He’s genuinely grateful to be alive, and still shocked that this is happening to people around him.
Lesley McClurg: And in that last conversation you had with him, he mentioned that he doesn’t believe in global warming?
Shayla Love: That’s true. We were talking about what Vibrio was doing in the water near his home, and he shared that he doesn’t believe in global warming. And I think what’s difficult is that we live through seasons every year — we feel cold every year — so we don’t necessarily notice that each year is the hottest on record. It’s hard to feel in real time. When you’ve lived somewhere your whole life, you can sense that things are changing, but it’s hard to pin down. So I asked him whether he felt like the summers had gotten hotter and longer. And he did agree with that.
I think there’s the lived reality of being in the climate we’re in, and then there’s the difficulty that comes when these things get politicized and you’re trying to track large-scale changes over the course of a lifetime. But what it goes to show is that he got the infection regardless of what he believes. The environments we live in are changing, and we’ll have to contend with that no matter what we think is the cause.
Lesley McClurg: Did you push back on him at all — point out that he might not have gotten this infection if climate change weren’t happening?
Shayla Love: I was about to go meet with a researcher named Rita Colwell, who has spent her entire career studying Vibrio — she’s in her eighties and has been at it for decades. She studies the entire Vibrio family, which includes cholera. I mentioned her to Vernon, told him she was also a longtime Maryland resident, and that she had explained how warmer water leads to more of these bacteria. He was really open to that framing. I think asking him to reflect on what this researcher had said, or on whether the summers felt hotter to him, was a way of having the conversation without using more loaded terms.
Lesley McClurg: You planted a seed for further investigation in his mind, I imagine. You report that in the near future, infections from climate-affected microbes will become more common — more stories like Vernon’s. Before we go further, let’s make sure we lay the groundwork: what exactly is a microbe, and what does that category include?
Shayla Love: I like to think about this through the lens of the tree of life. When we learn about the tree of life in elementary school, we tend to think of tigers and polar bears and big animals living in different parts of the world. But if you actually look at the tree of life, you can barely find humans or animals on it. We are a tiny twig on an enormous tree, and most of that tree is made up of microbes. Microbes are organisms you generally can’t see — some fungi are large enough to be visible, like mushrooms, but the category includes bacteria, protozoa, algae, archaea, and viruses, which we sometimes call microbes even though technically they’re not alive, since they can’t reproduce on their own. It’s this vast grouping of very small organisms that we live around and that live on and inside us constantly — and we mostly don’t think about them because they’re invisible.
Lesley McClurg: We’re talking about how climate change is affecting microbes. You just heard from Shayla Love, science writer and author of a piece in The New Yorker titled “Our Warming Planet Is a Petri Dish for New and Deadly Microbes.” We’ll be right back with Shayla. Stay with us. I’m Lesley McClurg.
