A RECENT cluster of bird flu cases among poultry farm workers in Colorado is the latest example of an undeniable truth: Climate change is putting people at greater risk of infectious diseases by creating a cauldron of conditions that allow them to thrive.
The cases also make clear that we still aren’t doing enough to rein in this virus, which for six months now has spread from wildlife to dairy cows to poultry and humans.
The Centres for Disease Control and Prevention (CDC) last 2 weeks reported six confirmed cases of bird flu among workers who had been culling chickens at a farm with a known outbreak. That brings us to 11 likely human infections in the US since 2022, 10 of which have occurred since April. There are surely others that have gone undetected given that more than 160 US dairy herds have been infected.
Researchers have long warned that climate change is creating a breeding ground for pathogenic outbreaks like this.
Warming temperatures and wetter conditions allow mosquitoes — which transmit diseases like dengue and malaria — to flourish in more parts of the world.
Habitat loss and crowding mean that transmission between species could become more common.
Fungi could adapt to thrive at higher temperatures, making fungal diseases more dangerous to humans.
Bird flu is no different. Last year, the CDC said that the number of bird flu outbreaks had increased in both animals and humans around the world over the last decade, due in part to shifts in migratory patterns driven by climate change.
That’s driven infections across a wide range of species — from a polar bear in the Arctic to penguins in Antarctica.
But the warming world is not only allowing bird flu to zoom around the globe. It’s also making dealing with the virus that much harder.
While updating reporters about the cluster of infections in Colorado, US health officials described a downright miserable scenario.
Outdoor temperatures had climbed to 104°F (40°C) and it was surely even hotter inside the barn where farm workers were culling chickens.
“We understand that PPE (personal protective equipment) use was not optimal, particularly masks and eye protection,” Nirav Shah, principal deputy director of the CDC, told reporters. And the industrial fans used to relieve the heat can stir up feathers, dust and debris that potentially carry the virus.
Tyvek suits are a good protective barrier from the virus, but also trap heat, notes Erin Sorrell, a senior scholar at the Johns Hopkins Centre for Health Security. And it’s hard to maintain a good seal on goggles and masks amid both the heat and the fans.
“We’ve all experienced a soggy N95 mask during the Covid days,” Sorrell adds. “It’s exceptionally uncomfortable and it’s not effective.”
This forces agricultural workers to make a terrible trade-off: Avoid bird flu by strictly adhering to proper safety gear or avoid suffering the worst effects of the extreme heat. Given that the farm-related bird flu cases in the US have so far been mild, ranging from only conjunctivitis to mild flu symptoms, with nobody ending up in the hospital, it’s not hard to imagine where many might land when weighing their risks.
But that’s not a calculation any worker should have to make. It’s bad for their personal health and it’s bad for public health. So far, the virus has yet to mutate in a way that allows it to easily spread among or cause more serious infections in humans.
Yet, each new human case is a chance for that to happen, upping the possibility of a pandemic. That’s a point the CDC itself made in its avian flu report, noting that, “as animal outbreaks increase, the risk of spread to people can also increase, along with opportunities for viral reassortment that can enhance transmissibility of avian influenza viruses.”
This problem will only get worse. As my Bloomberg Opinion colleague Mark Gongloff recently noted, the heat wave season continues to get longer and more deadly.
“We can’t expect [farm workers] to carry the weight of the world on their shoulders,” says Michael Mina, an epidemiologist and expert on infectious disease outbreaks. “We have to come up with better solutions.”
Those solutions should include
more humane working conditions, with mandated breaks when the temperature soars; guaranteed sick leave; improved access to health care; and better training on the proper use of PPE, as well as why that matters. (And eventually, we’re going to need PPE that functions better in hot places.) But the best approach would be to eliminate the risk from the work environment altogether.
Public health and agriculture officials continue to maintain that, despite the burning fuse of infections, it will be possible to stem the spread on farms. That’s a position that many infectious disease experts see as increasingly improbable given the slow-footed response from the US government.
The strain of the virus that infected poultry workers in Colorado appears to carry the same genetic signature as the one that infected cows at nearby dairy farms and is similar to the one that infected workers in Texas and Michigan, suggesting it had returned to chickens from dairy cows.
We’ve already demonstrated an inability to take the necessary steps to slow climate change. Let’s not botch our response to the health threats that spin out of it.
- This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.
- This article first appeared in The Malaysian Reserve weekly print edition
