AND WE HAVE CLIMATE CHANGE TO BLAME.
BY VICTOR TANGERMANN / DECEMBER 17 2020
According to a new study by researchers from the Centers for Disease Control and Prevention (CDC), Naegleria fowleri, better known as the “brain-eating amoeba,” is slowly making its way northwards from the southern United States — and we’ve got climate change to blame.
The news isn’t quite as gloomy as it sounds, Live Science reports. The actual number of yearly cases isn’t increasing; it’s just that they’re occurring over a larger geographic range.
The single-celled organism behind the infections is usually found in warm bodies of freshwater, including lakes and rivers. Once a person is infected — an exceedingly rare occurrence usually resulting from swimming or diving in infected waters — the amoeba travels from the nose into the brain.
Once there, the organism can kick off a nasty brain condition called primary amebic meningoencephalitis (PAM). And yep, according to the CDC, PAM is “usually fatal.”
The good news: there have only been 34 infections reported in the US in the last ten years, according to CDC data.
Since the amoeba prefers warm waters, up to what Live Science reports to be a hot-tub-like 113 degrees Fahrenheit, an upward shift in global temperatures caused by climate change is giving N. fowleri new opportunities to expand north over the last 40 years, according to the CDC study published in the journal Emerging Infectious Diseases this week.
The study, which examined CDC data from 1978 t0 2018, found that new cases moved northwards at about 8.2 miles per year.
“It is possible that rising temperatures and consequent increases in recreational water use, such as swimming and water sports, could contribute to the changing epidemiology of PAM,” the paper reads.
Deadly 'brain-eating amoeba' has expanded its range northward
The organisms' expanded range may be due to increased temperatures from climate change.
(Image: © Smith Collection/Gado/Getty Images)
By Rachael Rettner - Senior Writer 2 days ago
Deadly "brain-eating amoeba" infections have historically occurred in the Southern United States. But cases have been appearing farther north in recent years, likely because of climate change, a new study finds.
The study researchers, from the Centers for Disease Control and Prevention (CDC), examined cases of this brain-eating amoeba, known as Naegleria fowleri, over a four-decade period in the U.S. They found that, although the number of cases that occur each year has remained about the same, the geographic range of these cases has been shifting northward, with more cases popping up in Midwestern states than before.
N. fowleri is a single-celled organism that's naturally found in warm freshwater, such as lakes and rivers, according to the CDC. It causes a devastating brain infection known as primary amebic meningoencephalitis (PAM), which is almost universally fatal. Infections occur when contaminated water goes up a person's nose, allowing the organism to enter the brain through the olfactory nerves (responsible for your sense of smell) and destroy brain tissue. Swallowing contaminated water will not cause an infection, the CDC says.
Related: 5 key facts about brain-eating amoebas
Because N. fowleri thrives in warm waters, up to 113 degrees Fahrenheit (45 degrees Celsius), it's possible that warming global temperatures may affect the organisms' geographic range, the authors said.
In the new study, published Wednesday (Dec. 16) in the journal Emerging Infectious Diseases, the researchers analyzed U.S. cases of N. fowleri linked to recreational water exposure — such as swimming in lakes, ponds, rivers or reservoirs — from 1978 to 2018. They identified a total of 85 cases of N. fowleri that met their criteria for the study (i.e. cases that were tied to recreational water exposure and included location data.)
During this time, the number of yearly reported cases was fairly constant, ranging from zero to six per year. The vast majority of cases, 74, occurred in southern states; but six were reported in the Midwest, including Minnesota, Kansas and Indiana. Of these six cases, five occurred after 2010, the report said.
A map showing cases of Naegleria fowleri infections tied to recreational water in the U.S. from 1978 to 2018. (Image credit: CDC/Emerg Infect Dis. 2021 Jan)
The organisms' expanded range may be due to increased temperatures from climate change.
(Image: © Smith Collection/Gado/Getty Images)
By Rachael Rettner - Senior Writer 2 days ago
Deadly "brain-eating amoeba" infections have historically occurred in the Southern United States. But cases have been appearing farther north in recent years, likely because of climate change, a new study finds.
The study researchers, from the Centers for Disease Control and Prevention (CDC), examined cases of this brain-eating amoeba, known as Naegleria fowleri, over a four-decade period in the U.S. They found that, although the number of cases that occur each year has remained about the same, the geographic range of these cases has been shifting northward, with more cases popping up in Midwestern states than before.
N. fowleri is a single-celled organism that's naturally found in warm freshwater, such as lakes and rivers, according to the CDC. It causes a devastating brain infection known as primary amebic meningoencephalitis (PAM), which is almost universally fatal. Infections occur when contaminated water goes up a person's nose, allowing the organism to enter the brain through the olfactory nerves (responsible for your sense of smell) and destroy brain tissue. Swallowing contaminated water will not cause an infection, the CDC says.
Related: 5 key facts about brain-eating amoebas
Because N. fowleri thrives in warm waters, up to 113 degrees Fahrenheit (45 degrees Celsius), it's possible that warming global temperatures may affect the organisms' geographic range, the authors said.
In the new study, published Wednesday (Dec. 16) in the journal Emerging Infectious Diseases, the researchers analyzed U.S. cases of N. fowleri linked to recreational water exposure — such as swimming in lakes, ponds, rivers or reservoirs — from 1978 to 2018. They identified a total of 85 cases of N. fowleri that met their criteria for the study (i.e. cases that were tied to recreational water exposure and included location data.)
During this time, the number of yearly reported cases was fairly constant, ranging from zero to six per year. The vast majority of cases, 74, occurred in southern states; but six were reported in the Midwest, including Minnesota, Kansas and Indiana. Of these six cases, five occurred after 2010, the report said.
A map showing cases of Naegleria fowleri infections tied to recreational water in the U.S. from 1978 to 2018. (Image credit: CDC/Emerg Infect Dis. 2021 Jan)
What's more, when the team used a model to examine trends in the maximum latitude of cases per year, they found that the maximum latitude had shifted about 8.2 miles (13.3 kilometers) northward per year during the study period.
Finally, the researchers analyzed weather data from around the date each case occurred, and found that on average, daily temperatures in the two weeks leading up to each case were higher than the historical average for each location.
"It is possible that rising temperatures and consequent increases in recreational water use, such as swimming and water sports, could contribute to the changing epidemiology of PAM," the authors wrote.
Efforts to characterize PAM cases, such as knowing when and where these cases occur, and being aware of changes in their geographic range, could help predict when it's riskiest to visit natural swimming holes, the authors said.
Since there is no rapid test for N. fowleri in water, the only sure way to prevent these infections is to avoid swimming in warm freshwater, the CDC says. If you choose to go swimming in warm freshwater, you can try to avoid having water go up your nose by holding your nose closed, using nose clips or keeping your head above water.
Originally published on Live Science.
Finally, the researchers analyzed weather data from around the date each case occurred, and found that on average, daily temperatures in the two weeks leading up to each case were higher than the historical average for each location.
"It is possible that rising temperatures and consequent increases in recreational water use, such as swimming and water sports, could contribute to the changing epidemiology of PAM," the authors wrote.
Efforts to characterize PAM cases, such as knowing when and where these cases occur, and being aware of changes in their geographic range, could help predict when it's riskiest to visit natural swimming holes, the authors said.
Since there is no rapid test for N. fowleri in water, the only sure way to prevent these infections is to avoid swimming in warm freshwater, the CDC says. If you choose to go swimming in warm freshwater, you can try to avoid having water go up your nose by holding your nose closed, using nose clips or keeping your head above water.
Originally published on Live Science.
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