Bird flu is leaving a trail of death on Brazil’s southernmost beaches. At least 954 aquatic mammals (mainly wolves and sea lions, but also seals) have died from the H5N1 virus. Local authorities and researchers are working to bury the bodies as quickly as possible because the risk of contagion is very high. The pathogen has been transmitted from birds to mammals multiple times, via…
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Bird flu is leaving a trail of death on Brazil’s southernmost beaches. At least 954 aquatic mammals (mainly wolves and sea lions, but also seals) have died from the H5N1 virus. Local authorities and researchers are working to bury the bodies as quickly as possible because the risk of contagion is very high. Pathogens have been transmitted from birds to mammals many times through contact with infected animals or their feces. In some isolated cases, it has also been transmitted to people, but there have been no confirmed cases of human-to-human infection. Brazil’s powerful poultry industry fears the virus could spread from wild animals to farms.
The virus arrived in South America in late 2022 and has been spreading across the African continent. First, it killed thousands of birds and marine mammals in Peru, then moved to Chile, from there to Argentina and Uruguay, and finally spread to Brazil. Brazil detected its first sea lion case on October 3, with most deaths occurring that month.
In Argentina, a team from the NGO Argentine Wildlife Conservation Society, Universidad Centrale de Buenos Aires, and the University of California, Davis, documented baby elephant seals in the Valdes Peninsula between October and November. “Extreme Mortality”. , in Patagonia. They estimate that more than 17,000 calves died throughout Chubut province during this year’s breeding season. Normally, less than 1% of calves die, but this season 97% died. In addition to high mortality among young animals, scientists also observed a 40 to 70 percent decline in adult animal populations along the coast, with an “unusual” number of adult males and females dying.
Larissa Oliveira, a professor at the university’s mammal ecology laboratory, said by phone that there are no breeding grounds in Brazil, but sea lions breeding in Uruguay rest and eat on the Brazilian coast, which inevitably eventually displaces the virus. Aquatic Mammal Research Group of Rio dos Sinos (Unisinos) and Rio Grande do Sul (Gemars). “This is the first time we’ve seen such mortality in South America,” he said, warning that the virus appeared to be extremely contagious in these animals.
In the case of pinnipeds (family Sealidae and their close relatives), everything is made worse because they are very social animals, always in close proximity to each other. For viruses spread through the air and feces, this is ultimately fatal. Although little is known about the process, everything indicates that death is extremely painful for these mammals, with them experiencing disorientation, fever and seizures for up to 48 hours before death. So now when someone is found dead on a beach, official advice is to euthanize them by injection after they have been tested and confirmed to be infected.
There is also a protocol to bury them two meters under the sand as soon as possible to avoid being infected by scavenging birds such as seagulls or buzzards or even wild dogs, which are abundant on the beaches of southern Brazil. “If these animals come into contact with carcasses and become contaminated, they can carry the virus to urban centers and who knows if it will spread to the interior (…) There is a huge fear that the virus will reach aviaries in the interior of Brazil,” experts commented.
Brazil is the world’s second largest chicken producer and largest exporter, selling to 153 countries. In 2022, chicken production will be 14.5 million tons. According to the Ministry of Agriculture and Livestock, Brazil has exported 4.7 million tons from January to November this year, generating more than $8.8 billion for the economy.
The situation could be catastrophic if the flu spread to farms, but the department is currently calling for calm. He believes the high mortality rate of marine mammals on the country’s southern coast “does not increase the risk of introducing viruses into aviculture operations, whether commercial or subsistence poultry operations,” according to his emailed response.
The main risk is poultry coming into contact with infected wild birds, but for that to happen it would be enough for seagulls to eat sea lion carcasses, become infected, and then move around the farm. To this end, biosecurity measures are currently being strengthened at chicken farms near areas with a high number of wild animal cases, and breeders are being notified to be more vigilant and report suspected cases quickly.
The ministry also recalled that the fact that there are cases of avian influenza in wild animals or poultry does not affect a country’s classification of being free of the H5N1 virus in that country, according to the World Organization for Animal Health (WHO). Poultry. Commercial production. Therefore, there is currently no risk of trade restrictions against Brazil.