There is now a greater chance of disease outbreaks due to climate change – Can it be reduced?

Guest essay by Eric Worrall

A new study suggests that climate change is increasing people’s risk of bubonic plague. But the risk factors identified, even when the study is true, appear to be completely controllable.

There is now a greater chance of disease outbreaks thanks to climate change

Repost

Molly Taft
November 20, 2021 at 8:50 am

The risk of bubonic plague from humans to animals in the western United States has increased since 1950 due to climate change. research had found. Importantly, the study provides valuable insights into how this deadly disease has historically moved and evolved in the US, which may help us understand more about its future.

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Yersinia pestis are the bacteria that cause plague – including that plague, medieval Black Death, killing people around 25 million people for four years in the 1300s. The bacteria were transmitted to humans from animals, especially rats, which carried fleas that spread plague on humans. Scientists have theorized that bubonic plague, like many other infectious diseases, may increase its spread to humans as the planet warms and humans come into closer contact with animals. wild animals.

But there hasn’t been much research on the best historical conditions for bubonic plague to grow and spiral out of control. As a result, there are still a lot of big questions about the disease – like why it hasn’t spread to certain geographic areas, or why cases in humans don’t always overlap with those in animals. carrying disease – still unanswered.

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The study found that rodent communities in certain areas at higher elevations were up to 40% more likely to harbor disease, which the researchers attributed to warming since 1950. That means the risk of spreading plague from rodents to humans is also increased, though slightly more.

“It’s a big, messy, messed-up system, and there’s a lot of different levers that control the ecology of this disease,” says Carlson. “But when we start to identify the large regions, we can see how the key variables have changed since 1950, and it turns out that – more and more of these regions are starting to fit these conditions. Circumstances allowed plague in animals, and increasingly, to make the leap into humans. ”

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Read more: https://www.gizmodo.com.au/2021/11/the-plague-is-more-liability-now-thanks-to-climate-change/

Summary of the study;

Plague risk in the western United States through seven decades of environmental change

Colin J. Carlson, Sarah N. Bevins, Boris V. SchmidFirst published: November 18, 2021 https://doi.org/10.1111/gcb.15966

abstract

After a number of pandemics over the past two millennia, wildlife has become a reservoir for plague (Yersinia pestis) still exists around the world, including in the western United States. Routine surveillance in this area has produced comprehensive records of human cases and seroprevalence in animals, providing a unique opportunity to examine whether plague reservoirs are in progress. how to respond to environmental change. Here, we examine whether animal and human data suggest that plague reservoirs and risk of transmission have changed since 1950. To do so, we develop a method novel to detect the effects of climate change on infectious disease distribution, potentially suppressing long-term trends (signals) and annual variations in both weather and sampling (noise ). We found that plague clusters are associated with high-altitude rodent communities, and that soil biochemistry may play an important role in the geography of long-term survival. In addition, we found that human cases were concentrated in only a small subset of endemic regions, and that spillover events were driven by higher rodent abundance (amplification hypothesis) and climate anomalies (nutrient cascade hypothesis). Using our detection model, we found that due to climate change, high-altitude rodent communities have become more favorable to disease reservoirs — to a degree consistent increased by as much as 40% in some places — and the risk of spillover to humans is moderate — elevation also increased, albeit gradually. These results highlight opportunities for further investigation of plague ecology, the value of integrated surveillance for infectious disease geography, and the need for further research into the ongoing impacts of plague. Climate Change.

Read more: https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.15966

Plague is treatable with modern antibiotics, although it still kills a small number of people in the United States each year – antibiotic treatment must be started very quickly when plague is suspected for a chance to survive. Areas with endemic plague maintain vigilance against outbreaks.

I learned something new about bubonic plague – research shows it can survive in soil, like anthrax, allowing it to recur infrequently and infect local wildlife even when All live carriers are removed, although plague is sensitive to soil chemistry – only certain types of soil are suitable.

I think the biggest weakness of this study is that in my opinion it doesn’t go into why the distribution of modern plague is tied to a small number of species. Plague can infect many species of mammals. The study touched on this briefly, but I wanted to dig deeper into why the modern plague is so limited.

Since some of the lake animals are known to be protected species, I really doubt the reason why bubonic plague is still endemic in some parts of the US is that no one is baiting and eradicating it. animals in the lake. If an unacceptable threat to human life emerges, an intensive culling program that includes protected species, known carriers of disease, will be able to stamp out the threat, regardless of any climatic factors.