High pathogenic avian influenza H5N1 hits in unexpected places around the globe
GALAPAGOS ISLANDS, Ecuador; PUGET SOUND, Washington; DES MOINES, Iowa––Beyond the birding world, and only the small segment of that who pay attention to avian diseases, hardly anyone noticed the “canary in the coal mine” when on September 20, 2023 the Galapagos National Park Directorate announced that it had discovered the high pathogenic H5N1 avian influenza in three bird carcasses out of five tested.
The Galapagos National Park Directorate did try to rouse some public concern, but failed to mention why the public should be concerned, not only about birds but about other wildlife and human health and welfare.
Evolution of H5N1 would have fascinated Charlie D
“The Galapagos Islands, an archipelago located hundreds of kilometers off the coast of Ecuador,” the Galapagos National Park directorate explained in a media release, “are known for their large number of diverse and unusual endemic species, including finches and cormorants, which helped Charles Darwin develop his theory of evolution in the 1830s.”
Altogether, at least 185 bird species have been catalogued in the Galapagos Islands just since 2019, of whom 154 migrate––and migrate in all directions, north and south along the Pacific Flyway, east to South America, west out into the Pacific Ocean.
Thus the discovery of high pathogenic H5N1 in the Galapagos meant that if a major outbreak was not already spreading among the birds of the world for the second winter in a row, it soon would be.
At the time, though, most H5N1 observers seemed inclined to view the Galapagos cases as vagrant remnants of the 2022 outbreak, lingering strains of which had recently hit domestic poultry farms in Peru.
The first hint that the 2023 recurrence of H5N1 might be much more serious came on October 4, 2023 from Cassino Beach, Brazil, the 158-mile longest sea beach in the world, 3,200 miles southeast of the Galapagos Islands, but also a popular tourist destination.
Sea lions & fur seals
Multiple southern sea lions and fur seals were found dead there and at Hermenegildo beach, just to the south.
Individual southern sea lions and fur seals had previously been found dead from H5N1 in Peru, Chile, Argentina, and Uruguay, but these were the first known marine mammal deaths from H5N1 in Brazil, and this appeared to be the first case of marine mammal deaths occurring in large numbers.
A third “canary in the coal mine” fell two weeks later, 4,000 miles north of the Galapagos, but again the significance of it was initially overlooked.
“Bird flu, already killing seabirds in the Salish Sea, has jumped to harbor seals in the first documented instance of marine mammals dying from the disease on the West Coast,” the Seattle Times noted on October 5, 2023.
“The deaths were confirmed in testing five stranded seals on Marrowstone Island this summer,” the Seattle Times explained, “and suspected in a seal who stranded in August 2023, according to the National Oceanic and Atmospheric Administration West Coast Region, which announced the cross-species jump.
“Caspian terns were dying from the H5N1 strain of highly pathogenic avian influenza since July 2023 on Marrowstone and nearby Rat Island,” the Seattle Times mentioned. “The outbreak there has already killed an estimated 1,700 birds.”
Near ANIMALS 24-7
Both locations, in northern Puget Sound, are within a few miles of ANIMALS 24-7 as the gull flies, though on the far side of Puget Sound from us, and are visible from about a mile and a half down our road.
Nothing, however, resembling the beginning of a major H5N1 outbreak was evident here.
Since seals and sea lions hunt and scavenge sea birds, the local route of infection seemed clear.
Since no other marine mammals were reported dead in the area, the Marrowstone Island seal death looked like a fluke.
A day later, though, the U.S. Department of Agriculture told Reuters, the first outbreak of H5N1 at a U.S. commercial poultry farm in seven months brought the deaths of 47,300 turkeys in Jerauld County, South Dakota.
ABC4 simultaneously reported from Salt Lake City, Utah, that at least 142,000 turkeys
either died or were “depopulated” due to the discovery of H5N1 on a farm in Sanpete County, far to the southwest, over the Rocky Mountains.
The Jerauld County and Sanpete County outbreaks were more than 1,000 miles apart. No commercial trade routes link them.
Clearly H5N1 was––and is still––moving south from the Arctic Circle with the fall southern migration of waterfowl and other North American migratory species.
The order carnivora
Equally clearly, reassortment of the high pathogenic H5N1 virus has produced a variant strain that attacks marine mammal members of the order carnivora.
Seemingly isolated cases found occasionally for several years in deceased specimens of land-dwelling carnivora may no longer be flukes.
High pathogenic H5N1 may be on the verge of ceasing to be just “bird flu,” instead crossing over––like “swine flu”––to become seasonally endemic in mammals, perhaps including humans, who have by far the most exposure to potentially infected poultry.
Known in humans since 1996
Crossover cases of H5N1 killing humans have been documented since 1996.
To date, crossover cases have been rare, and have attacked mostly people involved in the poultry industry.
Most H5N1 transmission to domestic poultry flocks is believed to come directly from exposure to the guano and feathers of infected wild birds, but transportation of fowl to live markets and the movement of gamefowl associated with cockfighting are also among the major H5N1 vectors. Some H5N1 outbreaks have even occurred through bird movement by falconers.
The most recent known human victims of H5N1 were a 50-year-old man in Svay Rieng province, Cambodia, and a two–year-old girl living Prey Veng province, Cambodia, reported dead on October 7, 2023, and October 9, 2023, respectively.
Both the man and the girl were exposed to domestic poultry flocks believed to have died en masse from H5N1 just before the humans fell ill.
Southern Africa hit now, too
H5N1 and other versions of avian influenza are familiar scourges in Southeast Asia, which annually experiences the largest migrations of waterfowl of any part of the world.
Southern Africa, on the other hand, located far from the major Atlantic and Pacific flyways, has not historically experienced major H5N1 outbreaks, until just recently.
The World Organization for Animal Health on October 17, 2023 announced an H5N1 outbreak “on a farm of 54,207 laying hens aged between 23 and 30 weeks” in Mozambique, “kept in a high biosecurity facility,” where avian influenza of any sort should never have occurred.
“Neighboring South Africa, a leading poultry producer on the continent, is currently grappling with a major bird flu outbreak that killed millions of chickens,” the Program for Monitoring Emerging Diseases noted.
Translation: nowhere on Planet Earth can be considered safe.
Back in the U.S., the Center for Infectious Disease Research & Policy announced on October 18, 2023 that five states, including South Dakota, North Dakota, Minnesota, Montana, and Washington, “recently reported detections [of H5N1], which began picking up in early October after very low levels over the warmer months.
“Washington reported its first detection in poultry since February 2023,” the Center for Infectious Disease Research & Policy said, describing a case that “involves backyard poultry at a location with 10 birds in King County,” surrounding Seattle.
“The latest outbreaks in Montana and North Dakota also involve backyard birds,” the Center for Infectious Disease Research & Policy noted, using a phrase that is often a euphemism for gamefowl, itself a euphemism for fighting cocks.
More turkeys killed before Thanksgiving
In Minnesota and South Dakota, meanwhile, H5N1 took down nearly 200,000 turkeys at multiple farms in three counties.
That was just the beginning.
“Absent for seven months,” the Des Moines Register reported on October 20, 2023, “bird flu has again resurfaced in Iowa, hitting a commercial turkey facility in Buena Vista County and resulting in the destruction of 50,000 birds, the Iowa Department of Agriculture said.
“The news comes as poultry producers braced for fall migration,” the Des Moines Register continued.
“Wild birds, in particular waterfowl, can spread the virus to domestic flocks, often without showing signs of illness themselves,” the Des Moines Register continued, which is not exactly true; dying wild birds often fall far from human observation, and are promptly scavenged not only by other birds, such as crows, ravens, and eagles, but also by members of the order carnivora, including raccoons, foxes, coyotes, fishers, bobcats, and even bears.
“The current outbreak,” the Des Moines Register added, “which began in 2022, has resulted in the destruction of roughly 16 million laying hens, turkeys, and other birds in Iowa.
“Iowa, the nation’s top egg producer, tops the nation in birds destroyed during the long outbreak. Nationally, 59.4 million birds have been destroyed, U.S. Department of
Agriculture data shows, making it the single largest foreign animal disease outbreak in U.S. history.
“Since 2022,” the Des Moines Register finished, “Iowa has had 33 episodes of bird flu, while nationally, there have been 860.”
While U.S. concern about H5N1 continues to focus on domestic fowl, reports from South America suggest increasing reason for anxiety about wildlife, and about the likelihood of H5N1 mutating further to more easily infect non-avian species.
“Uruguay has admitted that some 400 sea lions have died and have been buried in 2-meter-deep graves, taking into account very special sanitary conditions to avoid contagion with H5N1,” the South American news agency MercoPress revealed on October 12, 2023.
Tests done on sea lions found dead along the Uruguayan coastline “have tested 43% positive, which means the real number of dead animals could be closer to 800,” MercoPress said.
“So far,” MercoPress advised, “not much more can be done, because the sea lions are feeding on dead or sick sea birds infected with H5N1.”
Penguins & skuas
On October 23, 2023, the British Antarctic Survey reported that, “Highly pathogenic avian influenza (HPAI) has been confirmed in brown skua populations on Bird Island, South Georgia––the first known cases in the Antarctic region,” where the relatively isolated native species of both birds and marine mammals can be expected to have little natural resistance.
“Natural pathways are the primary means of spread of high pathogenic avian influenza,” the British Antarctic Survey said. “It is likely that the spread of the disease was caused by the return of birds from their migration to South America.”
On the same day the Chilean Fisheries National Service reported the deaths of 2,917 Humboldt penguins, among 21,819 sea birds found dead from H5N1 between February and October 2023.
The Argentinian government veterinary service SENASA on October 25, 2023 confirmed finding high pathogenic H5N1 “in elephant seal pups at the sites of mass mortalities,” Argentine veterinarian Marcela Uhart told the Program for Monitoring Emerging Diseases.
“The loss of newborns is estimated to be near total,” Uhart said, “and the fate of reproductive females is unknown because they seem to have abandoned the beaches prematurely.
“Confirmed positive kelp gulls and South American terns were found at the same sites.”
More than 1,300 elephant seal pups were reported dead.
Actual mortality ranged from 56% to 74%, depending on location.