The threat of avian influenza: how to stop epidemics in animals from reaching humans?

inside Argentinapublic animal health agencies, Senasa230 confirmed dead sea ​​lion with one hair Last August, along the Atlantic coast, from Buenos Aires to Tierra del Fuego.exist Finland120,000 people were sacrificed fox and mink To control outbreaks on fur farms. more than 1,700 birds and seals They also died near Fort Flagler State Park in Washington state USA.

These are just some of the latest Victims of the global bird flu epidemic technically known as “Animal Diseases of All Humans” Due to the diversity of animal species it affects.Has not stopped growing since 2021 “Amazing ratio” The death rate is high, as the World Health Organization warns pan american health organization.

this is a killed wild animalsproduces Economic losses in terms of poultry productionand involves risk potential human pandemic If viruses can evolve and adapt person-to-person transmission. How to stop this epidemic?

so far As of December 2021, only 8 cases of avian influenza have been reported. Three of them reside in the United States: the United States (April 2022), Ecuador (January 2023) and Chile (March 2023). Symptoms include cough, diarrhea, shortness of breath, fever, headache, malaise, muscle aches and runny nose.

he H5N1 virus The virus was first detected in waterfowl in southern China in 1996. But recently, a subtype of the virus belonging to clade 2.3.4.4b emerged and became dominant in Asia, Africa, Europe, and the Middle East by the end of 2021, and then continued in the United States.

“This is highly pathogenic avian influenza virus H5N1 clade 2.3.4.4b originating from producing animals. Initial containment of this pathogen failed, but its spread around the world was very effective,” he explained database argentinian scientist Marcela UhartVeterinarian, graduated from the National University of the Center of the Province of Buenos Aires (UNICEN), currently Director of the Latin American Program at the Wildlife Health Center of the Province of Buenos Aires University of Californiain Davis, USA.

Oceania and Antarctica are the only regions without their circulation.But Dr. Uhart, along with colleagues from other countries World Organization for Animal Health (WHO) and World Food Organization (FAO) Influenza Expert Network They sounded the alarm a few days ago: bird flu could spell environmental disaster for Antarctica’s fauna.

“Before 2022, South America has never had a virus transmission. Therefore, the animals have no immunity, and this is one of the factors that has caused so many deaths. The same situation now applies to Antarctica, but there are exacerbating factors,” Uha Special said.

He referred to the fact that on the so-called “White Continent” several species breed and reproduce in very dense populations, a peculiarity that may favor the spread of pathogens. In addition, populations of certain species only live in that part of the world and are therefore more vulnerable. If they are affected by the bird flu virus, they may be affected more than populations in other areas.

He emphasized in the dialogue: “This pathogen is produced from the intensive production of poultry, where many animals gather in a small space.” database Paul Squareveterinarian, doctor of biology and researcher komasiu state university and CornichetLast summer, he conducted a collaborative study with sea lions affected by bird flu in Peru.

“The virus then spread to wildlife. This is worrying because it has caused serious damage to all kinds of wild birds. In Peru alone, more than 200,000 birds have died and it is now affecting all kinds of birds around the world. Mammals,” Prasa said.

What is important, he stressed, is prevention, “for this we must start questioning how we produce animals for food. This is a detached aspect; this emerging Pathogens will continue to emerge.”

Worldwide, it has been found in ferrets, mink, European otter, North American river otter, sea otter, mountain lion, pecan, European polecat, lynx, lynx, house cat, red fox, coyote, northern raccoon, raccoon dog, South American Jungle dog, American black bear, brown bear, grizzly bear, gray seal, common seal, porpoise, bottlenose dolphin, cat, dog, Japanese raccoon dog, Chilean dolphin, black dolphin, etc.

same species sea ​​lion with one hair A storm that hit the coasts of Peru and Chile in the summer also affected the coast of Argentina.It is also known as the South American sea lion, and its scientific name is Sophora flavescens.

“So far, no pathogen has affected South American sea lion populations as badly as bird flu this year. We still don’t know the extent of the problem,” he admitted. Enrique Crespo,researcher Marine Systems Research Centerof Cornichet Located in Puerto Madryn, Chubut Province, it has been dedicated to the study of this species for more than thirty years.

More bird flu outbreaks reported among sea lions on Friday Puerto Madryn, Chubut and Sierra Grande, Rionegro, Senasa reviewed the preventive measures again. Do not approach dead animals or marine mammals or wild and domestic birds (mainly ducks, hens, chicks, roosters, geese, turkeys) with suspicious symptoms, the Argentine National Institute of Health must be notified. It also should not be taken to beaches where sick or dead animals are present.

“There is always a risk for humans around infected birds and animals. A person can become infected by touching a sick bird or animal, or by touching a surface with the virus on it and then touching their nose, mouth or eyes.” database doctor Oladel OgonsetanProfessor of Population Health and Disease Prevention, Public Health Program University of California, in Irving, USA.

“The virus can also be spread by inhaling airborne droplets or dust. Human-to-human transmission is very rare, but possible,” he added.

The pathogen is “very virulent to humans, typically killing more than 50 percent of those infected,” Ogunseitan said. “In accordance with the One Health approach, human infection surveillance and rapid response are critical to preventing animal-environmental – Human interface mediated outbreaks are very important.”

“When avian influenza viruses are detected in birds and other animals such as sea lions, it is important that trained specialists equipped with appropriate personal protective equipment handle sick or dead specimens and dispose of them through disinfection and surveillance. Carcasses and waste. U.S. experts advise to “limit human access to remaining animals in the area”.

For Dr Uhart, there may be different mitigations: “For wild birds, we will have to wait for the outbreak to end, for the surviving populations to develop protective antibodies that confer immunity. Assessing the impact on biodiversity. Some countries are already using vaccination in poultry production. At the same time, everything must be done to control other issues affecting animal populations, such as pollution, climate change and overfishing.

from World Health Organization (WHO) and WHO, made recommendations to countries as measures to prevent further outbreaks. One of these is improving biosecurity on farms and in the poultry value chain and adopting good hygiene practices. “They might consider vaccinating poultry as a supplemental disease control tool.”

In addition, each country must have the capacity to detect, notify and rapidly respond to outbreaks in animals, as a first line of defense, and routinely genetically sequence viruses.

inside Humanity Among other measures, surveillance for severe acute respiratory infection and influenza-like illness should be prioritized (as symptoms of avian influenza are similar to those of seasonal influenza).Health agencies make it clear: Every country should “Ensuring pandemic preparedness at all levels”.

We cannot predict when the next influenza pandemic will occur, nor can we predict what virus will cause the next influenza pandemic. Tim UyekiMedical Director, Influenza Unit, Ministry of Health Centers for Disease Control and Prevention (CDC) of USA. But the history of bird flu viruses bears out experts’ fears.

The likely causative agent of the 1918 pandemic was the Avian Influenza A virus. The 1957 H2N2 and 1968 H3N2 influenza viruses were the result of genetic combinations of human influenza A viruses and low pathogenicity avian influenza A viruses.

The 2009 H1N1 influenza A pandemic was the result of a combination of human, avian and porcine influenza A virus genes, believed to have originated in pigs and spread from person to person.