Ten keys to understanding bird flu outbreak in sea lions in Argentina

Photo Diego Izquierdo
Photo: Diego Izquierdo.

if Avian Influenza It can be transmitted to humans or to more marine species, including those consumed by humans, and how it differs from the influenza virus that caused the pandemic in 2009 are some of the questions experts answer after registration sea ‚Äč‚Äčlion infection – Argentina was the first to show a highly pathogenic variant in a mammal with a mortality rate of almost 100%.

Since mid-August, in Tierra del Fuego, Santa Cruz, Chubut, Rionegro and Mar del Plata, Necochea, Monte Hermoso, Gesse in Buenos Aires Some 200 sea lions have been found dead in towns such as Villa delle and Colonel Rosales.

Consultants TeramNational Institute of Agricultural Technology (INTA) Veterinarians who specialize in poultry viruses, Ariel Vagnozzialong with biologists and researchers from Conicet and the National University of Mar del Plata (Unmdp), Diego Rodriguezprovides some keys to understanding this phenomenon.

What is bird flu?

“This is the name of a highly contagious disease produced by the influenza A virus. There are several subtypes within the genus,” Vagnozzi noted, including the H5N1 subtype registered in sea lions.

“All variants of influenza A are found only in wild birds; therefore, they are considered to be important reservoirs of the virus and play a very important role in the global spread of the disease,” he added.

Is it related to the H1N1 subtype of virus that caused the pandemic in 2009?

INTA experts said: “H1N1 is influenza A, which is the cause of the outbreak in humans. The two viruses are not related, and the H1N1 virus originated in pigs.”

Photo Diego Izquierdo
Photo: Diego Izquierdo.

How did bird flu reach Argentine sea lions?

“The virus arrived in South America last year via migratory birds,” Rodriguez said. “Earlier this year, the worst cases were in Peru, where seabirds had a high mortality rate. The virus mutated and infected sea lions, whose deaths The rate is also high,” explained.

He continued: “Due to the migration of animals, the virus spread south, and by the middle of the year there were deaths in southern Chile, and a few weeks earlier due to the interaction between the Pacific and Atlantic colonies, the virus had spread to southern Chile.” A few days later. Tierra del Fuego and up (to the Argentinian coast) can be reached within . “

What are the symptoms of an infected animal?

“Avian influenza is a respiratory disease, so of course it causes difficulty breathing and a lot of mucus. It also has neurological effects, manifested by disorientation, lack of coordination and even immobility in the infected animal,” explains the Unmdp researcher .

“It’s a highly contagious disease, almost 100 per cent fatal. Except for those animals with very good immunity and very low infection rates, there is no outcome other than death,” he added.

How do these infectious diseases affect the viability of the species?

With regard to sea lions in particular, Rodriguez said the death toll in the country is about 200, “not that catastrophic so far, but you have to be on top and see that evolve.”

In Peru and Chile, the impact has been “very severe, with thousands of animals killed, but not to the point of endangering the survival of the populations,” he said.

Is it possible for the virus to spread to other species?

“One of the most relevant features of the influenza virus is its ability to evolve, making it possible to infect a wide variety of animal species. If an outbreak in sea lions persists for a long time, we cannot predict how the situation will persist,” Vagnozzi said. “The time has come,” or whether the virus will infect other species, including humans.

However, he emphasized, “transmission from one species to another is usually infrequent, and when that happens, the virus is not always able to spread in an epidemic fashion because it needs to adapt.”

Photo Diego Izquierdo
Photo: Diego Izquierdo.

Given that the more genetically close the new infecting species is, the “easier” this adaptation is, are humans at greater risk in the face of recent mammalian cases?

“The possibility of avian influenza virus jumping to humans is possible, but very low. The fact that viral infection is found in mammals in nature may mean that the probability is increased. Approaching animals killed by influenza and handling them Will increase a little.” Possibility,” warns the veterinarian.

However, he assured that transmission to mammals (marine cats, feral and domestic cats, foxes, ferrets and raccoons) has been reported in the world and that “so far no sustained transmission in humans has been recorded”, which It’s just that “the number of cases in the world is relatively small and there is no human-to-human transmission.

Can sea lion infections be transmitted to marine species eaten by humans?

“Regarding fish, molluscs, crustaceans and other aquatic products, there have been no apparent bird flu infections so far,” Rodriguez said.

Will the outbreak affect the summer in the affected areas?

“Infections in Peru and Chile lasted about a month and a half to two months, and we expect infections here to be faster,” the biologist said.

Given the precedent in the region, authorities in affected areas expect the outbreak in Argentina to end by summer, although the outbreak is currently “in full swing” and its duration depends on wildlife dynamics.

Any advice for people in affected areas?

With the goal of “avoiding cross-contamination,” experts unanimously advise people not to travel to areas where inanimate or symptomatic sea lions are present, especially not to bring pets, to avoid eventual exposure to sea lions. Virus.

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