On Wednesday, the government released figures indicating that more than 3,300 sea lions in Chile have likely died from the H5N1 bird flu, a doubling in less than three weeks.
The outbreak has also affected various other animals, such as sea otters, dolphins, porpoises and penguins. The National Fisheries and Aquaculture Service (SERNAPESCA) has reported a significant increase in the number of sea lions found dead this year, with at least 3,347 victims recorded so far, up from 1,960 on April 6. The latter figure is twice as many as the 1,535 deaths documented at the end of March.
South American sea lions are experiencing an unusually high mortality rate. In addition to the 3,300 sea lions in Chile believed to have died from bird flu, around 3,500 sea lions in Peru, which shares a border with Chile, also succumbed to the disease in early March.
This raises concerns about the possibility of mammal-to-mammal transmission. Other marine species in Chile have also been affected by the bird flu epidemic, with Humboldt penguins being the most affected. To date, 933 deaths have been reported this year, which is estimated to be around 8.5% of the entire Humboldt penguin population in Chile.
María Soledad Tapia Almonacid, head of the aquaculture department, said the estimated total population of Humboldt penguins in their country is not very high, with no more than 11,000 individuals. This is due to their localized distribution.
She expressed concern that the current situation could lead to a loss of almost 10% of this species. Additionally, SERNAPESCA reported that two Chilean dolphins tested positive for H5N1 avian flu, marking the first time dolphins have been affected by the virus in the South American country. At least nine other Chilean dolphins were also found dead.
Other marine animals, including 16 sea otters and 15 porpoises, closely related to narwhals and beluga whales, are also thought to have died of bird flu. In the previous month, Chile reported its first-ever case of human infection with H5N1 avian influenza, which was discovered in the northern town of Tocopilla.
The 53-year-old was last reported in critical but stable condition, and it remains unclear how he contracted the virus. The global spread of the H5N1 clade 126.96.36.199b has raised concerns about the emergence of a future variant that could potentially be transmitted from human to human. Although there have been a few cases of human infection after contact with infected birds, the recent spread of the virus to increasing numbers of mammals has added to these concerns.
On February 24, Dr. Sylvie Briand, a WHO official, expressed concern about the global H5N1 situation. She said the virus is widely distributed in birds around the world and there are increasing reports of cases in mammals, including humans. She stressed that the WHO takes this risk seriously and urges all countries to be extra vigilant.