Avian flu was first confirmed in Chile in early December, but so far we've only seen a handful of HPAI related marine strandings reported (see Chile: SERNAPESCA Reports Avian H5N1 In Dead Sea Otter (Lontra feline).
532 sea lions, 234 Humboldt penguins and 6 chungungos (marine otters) have been found dead in those 3 months, compared to just 131 during all of 2022.
There are a few caveats. Only about 1/3rd of these carcasses have been sampled (n=187), and only small number of those (n=13) have tested positive for HPAI H5N1. Surveillance is obviously heightened due to the arrival of HPAI, which may skew the comparison to past years, and the condition of the recovered carcasses is not mentioned in this report.
Given the nearly 6-fold increase in marine animal deaths, and their concentration in the northern regions where HPAI first arrived, authorities are attributing most of this unusual mortality event to H5N1.
The full (translated) report follows.
SERNAPESCA delivers report of stranded marine animals dead due to Avian Influenza situationSaturday March 18, 2023 - There are more than 700 specimens of common sea lions, Humboldt penguins and chungungos that have been stranded dead on the coasts of our country during the first quarter of 2023, mainly in the north. The figure is 482.4% higher than the total number of strandings, corresponding to these species, registered in 2022.The National Fisheries and Aquaculture Service has reported a considerable increase in the strandings of dead marine animals on the Chilean coasts during the first quarter of 2023. In total, 532 specimens of sea lions, 234 Humboldt penguins and 6 chungungos are reported. that have stranded dead on the coasts of the northern macrozone, the main affected regions being: Arica and Parinacota with 292 dead sea lions and Atacama with 139 dead Humboldt penguins.“During these three months of the year we recorded a historical number of dead stranded marine animals, corresponding to 763 specimens of these three species. The total number of these stranded animals dead for a full year in 2022 was 131, and in 2021 there were 120 dead specimens in total. This shows that we are clearly facing an anomalous situation, which we attribute to the phenomenon of highly pathogenic avian influenza, especially since the strandings in these months are concentrated in the northern zone," said Soledad Tapia, National Director of Sernapesca.In the context of the Avian Influenza emergency, work has been reinforced with other entities such as the Presidential Delegations, Regional Governments, SAG, Seremías, Municipalities and others, in order to support an active surveillance plan throughout the coastline with the in order to reduce the risks of viral circulation of said disease, through the detection, testing and final disposal of affected animals.The epidemiological situation of highly pathogenic avian influenza (HPAI) by H5 subtype of Eurasian lineage has continued to spread. There are 4 regions of the northern macrozone that have registered marine fauna protected by the Fisheries and Aquaculture Law with positivity for avian influenza, only excepting the Atacama region that does not register official positive cases sampled, for now.To date, a total of 13 specimens of marine animals confirmed as HPAI-positive have been counted, corresponding to 1 chungungo in the Arica region; 8 sea lions, 2 in the Arica Region, 3 in Tarapacá, 2 in Antofagasta and 1 in Coquimbo; and 4 Humboldt Penguins, 1 in Tarapacá, 2 in Antofagasta and 1 in Coquimbo. This from a total of 183 specimens that were sampled.It should be noted that SERNAPESCA is prioritizing assistance to the strandings of animals with symptoms associated with avian influenza. As for the disposal of, please report to 800 320 032.es and Aquaculture Service to protect the biosafety protocols.The service reiterated the emphatic call to people who are on the coastline not to touch or manipulate, keep their distance, and report in the event that a dead bird or marine animal is detected on the coastline or that shows signs such as: decay, coughing, breathing difficulties or muscle spasms. This includes not moving them, not returning them to the sea or burying them on beaches at your own expense. Therefore, in case of observing cases of marine animals stranded on beaches, please report to 800 320 032.
Aside from tragic loss of these animals, there is the obvious concern that the virus may becoming better adapted to mammalian hosts. While mammal-to-mammal transmission of the virus has not been confirmed in these cases, it remains a distinct possibility.
For recent research articles on HPAI H5 in marine mammals, you may wish to revisit: