sharon sanders
Editor-in-Chief & President
23 August 2023
Southward expansion of high pathogenicity avian influenza H5 in wildlife in South America: estimated impact on wildlife populations, and risk of incursion into Antarctica
Abstract
This report summarizes the spread of high pathogenicity avian influenza of the subtype H5 (HPAI H5) clade 2.3.4.4b in South America since it was first detected in the region in October 2022, and evaluates the risk for incursion into Antarctica in the near future. The focus of the report is on HPAI H5 in wildlife, and not spread in poultry or rare spillover to humans, as these are the subject of other reports. We do recognize and fully support a One Health approach to HPAI H5: an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals (both wild and domestic) and ecosystems. Since HPAI H5 was first reported in Colombia in October 2022 (WAHIS, 2022a), it has spread across South America with devastating consequences for its wild bird and mammal populations (GamarraToledo et al, 2023b; Leguia et al, 2023). In Peru and Chile, more than 500,000 wild birds of at least 65 species and more than 20,000 wild mammals of at least 15 species were reported dead, with actual mortality likely many times larger. This mortality is a potential threat to the conservation of several wild animal species. For example, HPAI-H5-associated losses included about 36% of the endangered Peruvian pelican (Pelecanus thagus) population in Peru, about 13% of the vulnerable Humboldt penguin (Spheniscus humboldti) population in Chile, and about 9% of the South American sea lion (Otaria flavescens) population in Peru and Chile. After its first detection in South America, HPAI H5 virus has spread rapidly to the southern tip of South America (south of 40°S latitude), a distance of more than 6000 km in just three months. The recently reported detection of this virus in a South American sea lion at Puerto Williams, Chile (54.9S), is the southernmost detection of the virus to date. There is a substantial risk it will continue southwards and in the near future reach Antarctica and its offshore islands, which are home to more than 100 million breeding birds, 6 species of pinnipeds and 17 species of cetaceans. This risk may be increased in coming months due to the spring migration of wild birds from South America to breeding sites in the Antarctic. The negative impact of HPAI H5 on Antarctic wild birds and mammal populations could be immense, both because of their likely susceptibility to mortality from this virus, and their occurrence in dense colonies of up to thousands of pinnipeds and hundreds of thousands of birds, allowing efficient virus transmission. Although little can be done to stop HPAI H5 from spreading to Antarctica and causing mortality in Antarctic wild birds and mammals, there are several detection and response options possible. These include surveillance and accurate documentation of HPAI-H5-associated mortality events, and following guidelines to reduce risk of human-mediated virus spread.
https://www.offlu.org/wp-content/up...ment-HPAI-wildlife-South-America-20230823.pdf
Southward expansion of high pathogenicity avian influenza H5 in wildlife in South America: estimated impact on wildlife populations, and risk of incursion into Antarctica
Abstract
This report summarizes the spread of high pathogenicity avian influenza of the subtype H5 (HPAI H5) clade 2.3.4.4b in South America since it was first detected in the region in October 2022, and evaluates the risk for incursion into Antarctica in the near future. The focus of the report is on HPAI H5 in wildlife, and not spread in poultry or rare spillover to humans, as these are the subject of other reports. We do recognize and fully support a One Health approach to HPAI H5: an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals (both wild and domestic) and ecosystems. Since HPAI H5 was first reported in Colombia in October 2022 (WAHIS, 2022a), it has spread across South America with devastating consequences for its wild bird and mammal populations (GamarraToledo et al, 2023b; Leguia et al, 2023). In Peru and Chile, more than 500,000 wild birds of at least 65 species and more than 20,000 wild mammals of at least 15 species were reported dead, with actual mortality likely many times larger. This mortality is a potential threat to the conservation of several wild animal species. For example, HPAI-H5-associated losses included about 36% of the endangered Peruvian pelican (Pelecanus thagus) population in Peru, about 13% of the vulnerable Humboldt penguin (Spheniscus humboldti) population in Chile, and about 9% of the South American sea lion (Otaria flavescens) population in Peru and Chile. After its first detection in South America, HPAI H5 virus has spread rapidly to the southern tip of South America (south of 40°S latitude), a distance of more than 6000 km in just three months. The recently reported detection of this virus in a South American sea lion at Puerto Williams, Chile (54.9S), is the southernmost detection of the virus to date. There is a substantial risk it will continue southwards and in the near future reach Antarctica and its offshore islands, which are home to more than 100 million breeding birds, 6 species of pinnipeds and 17 species of cetaceans. This risk may be increased in coming months due to the spring migration of wild birds from South America to breeding sites in the Antarctic. The negative impact of HPAI H5 on Antarctic wild birds and mammal populations could be immense, both because of their likely susceptibility to mortality from this virus, and their occurrence in dense colonies of up to thousands of pinnipeds and hundreds of thousands of birds, allowing efficient virus transmission. Although little can be done to stop HPAI H5 from spreading to Antarctica and causing mortality in Antarctic wild birds and mammals, there are several detection and response options possible. These include surveillance and accurate documentation of HPAI-H5-associated mortality events, and following guidelines to reduce risk of human-mediated virus spread.
https://www.offlu.org/wp-content/up...ment-HPAI-wildlife-South-America-20230823.pdf