Two More Bird Flu Cases Reported in Colorado Poultry Workers

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By:

Robin Foster

Published on: 

Jul 22, 2024, 4:27 am

Updated on: 

Jul 22, 2024, 4:27 am

MONDAY, July 22, 2024 (HealthDay News) — Two more cases of bird flu have been reported in Colorado poultry workers, but reassuring research finds the virus doesn’t seem to be fueling silent infections, U.S. health officials report.

The two additional H5N1 avian flu infections bring the total in that state to six, the U.S. Centers for Disease Control and Prevention said in a health advisory posted Friday.

“Since April 2024, 10 human cases of avian influenza A[H5] infection have been reported in the United States. Four of these cases were associated with exposure to sick dairy cows and six were associated with exposure to H5N1-infected poultry,” the CDC stated. “This includes two additional cases in Colorado that were confirmed by CDC this week and not previously reported. The two new cases were in poultry workers with exposure to infected poultry during depopulation and disposal activities. Similar to previous cases, illness was mild.”

Along with the new cases, the agency offered up some good news: Last month, the Michigan Department of Health and Human Services launched a study of 35 workers who were around cows sickened by the bird flu.

One question that researchers wanted to tackle was if there were people who never had symptoms but showed evidence of past infections. However, none of the blood testing showed antibodies that would indicate past infection, the CDC reported.

“This is an important finding because it suggests that asymptomatic infections in people are not occurring and provides support to the current testing approach — i.e., collecting samples from symptomatic people who have been exposed to sick animals,” the agency noted in its advisory.

Since 2020, a bird flu virus has been spreading among mammals — including even alpacas. Earlier this year the virus, known as H5N1, was detected in U.S. dairy cows, and it is now circulating in livestock in multiple states.

The cases reported earlier this year were among dairy farm workers in Michigan, Texas and Colorado.

As of last Friday, the H5N1 virus has been confirmed in 157 dairy cow herds in 13 states. Since April 2024, the U.S. Department of Agriculture has reported bird flu cases in 34 commercial flocks and 16 backyard flocks, for a total of 18.3 million birds affected.

More information

The CDC has more on the bird flu outbreak.

SOURCES: U.S. Centers for Disease Control and Prevention, news release, July 19, 2024

ENVIRONMENT19 July 2024

https://www.sciencealert.com/earths-water-is-rapidly-losing-oxygen-and-the-danger-is-huge

ByJESS COCKERILL

(Colors and shapes of underwater world/Getty Images)

Supplies of dissolved oxygen in bodies of water across the globe are dwindling rapidly, and scientists say it’s one of the greatest risks to Earth’s life support system.

Just as atmospheric oxygen is vital for animals like ourselves, dissolved oxygen (DO) in water is essential for healthy aquatic ecosystems, whether freshwater or marine. With billions of people relying on marine and freshwater habitats for food and income, it’s concerning these ecosystems’ oxygen has been substantially and rapidly declining.

A team of scientists is proposing that aquatic deoxygenation be added to the list of ‘planetary boundaries‘, which in its latest form describes nine domains that impose thresholds “within which humanity can continue to develop and thrive for generations to come.”

So far, the planetary boundaries are climate change, ocean acidification, stratospheric ozone depletion, interference with the global phosphorus and nitrogen cycles, rate of biodiversity loss, global freshwater use, land-system change, aerosol loading, and chemical pollution.

A team led by freshwater ecologist Kevin Rose from Rensselaer Polytechnic Institute in the US is concerned that this list overlooks one of the Earth’s most important limits.

“The observed deoxygenation of the Earth’s freshwater and marine ecosystems represents an additional planetary boundary process,” the authors write, “that is critical to the integrity of Earth’s ecological and social systems, and both regulates and responds to ongoing changes in other planetary boundary processes.

“Relevant, critical oxygen thresholds are being approached at rates comparable to other planetary boundary processes.”

The concentration of dissolved oxygen in water drops for a number of reasons. Warmer waters can’t hold as much dissolved oxygen, for instance, and with greenhouse gas emissions continuing to raise air and water temperatures above their long-term averages, surface waters are becoming less able to hold on to this vital element.

Dissolved oxygen can also be depleted by aquatic life faster than it is replenished by the ecosystem’s producers. Algal blooms and bacterial booms triggered by an influx of organic matter and nutrients in the form of agricultural and domestic fertilizers, sewage, and industrial waste, quickly soak up available dissolved oxygen.

In the worst cases, the oxygen becomes so depleted that the microbes suffocate and die, often taking larger species with them. Populations of microbe that don’t rely on oxygen then feed on the bounty of dead organic material, growing to a density that reduces light and limits photosynthesis to trap the entire water body in a vicious, suffocating cycle called eutrophication.

Aquatic deoxygenation is also driven by an increase in the density difference between layers in the water column. This increase can be attributed to surface waters warming faster than deeper waters and melting ice decreasing surface salinity in the oceans.

The more distinctly defined those layers are, the less movement there is between those layers of the water column, which the vertical strata of underwater life relies upon. These density fluctuations power the movement of oxygenated surface water into the deep, and without this temperature-powered freight, ventilation in the lower depths of aquatic environments grinds to a halt.

All this has wrought havoc on aquatic ecosystems, many of which our own species rely on for our own food, water, incomes, and wellbeing.

The paper’s authors call for a concerted, global effort to monitor and research deoxygenation of the ‘blue’ parts of our planet, along with policy efforts to prevent rapid deoxygenation and the associated challenges we are already beginning to face.

“Reducing greenhouse gas emissions, nutrient runoff and organic carbon inputs (for example, raw sewage loading) would slow or potentially reverse deoxygenation,” they write.

https://927c80333300bb9e859bddce24f1f53d.safeframe.googlesyndication.com/safeframe/1-0-40/html/container.html

“The expansion of the planetary boundaries framework to include deoxygenation as a boundary [will help] to focus those efforts.”

This paper was published as a Perspective in Nature Ecology & Evolution.