2020–2024 H5N1 outbreak

Since 2020, global cases of avian influenza subtype H5N1 have been rising, with cases reported from every continent as of February 2023 except for Australia and Antarctica. In late 2023, H5N1 was discovered in the Antarctic for the first time, raising fears of imminent spread throughout the region, potentially leading to a "catastrophic breeding failure" among animals that had not previously been exposed to avian influenza viruses. The virus involved in the outbreak is classified in H5 clade 2.3.4.4b.