Swan deaths with avian influenza H5N6 recorded in Xinjiang, China

By Ma Ming & Han Xinlin
(Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Xinjiang, P.R. of China)

With the warmer winters associated with climate change, thousands of swans now remain in Northern Xinjiang during the winter months, where several outbreaks of avian influenza have also been recorded in swans in the region. Cooperative monitoring of avian influenza in waterbirds has been carried out in several Central Asian countries over the last 15 years, and 4 species of swans are known to be threatened by the disease.

Distribution and number of swans dying of avian influenza
(H5N6) in Xinjiang, China

Cases have been recorded for Whooper Swans, Mute Swans, Tundra Swans and Black Swans. The largest mortality event occurring in early 2020, when the highly pathogenic H5N6 subtype of the virus killed at least 76 swans across 4–5 locations in the Xinjiang Uygur Autonomous Region, across an area of 700 x 300 km2. The region is occupied by about five million people (including in Yining County, Bole City, Manas County and Korla City) and, although this incident did not pose a direct threat to human life (i.e., it did not spread to humans), it caused social panic and innocent poultry species were culled with the aim of reducing spread of the disease. According to the literature, various types of avian influenza have previously occurred in other provinces in China, and some variants (e.g. H5N1) have transmitted to people.

Whooper Swan cygnet recovered in Xinjiang (Photo: Han Xinlin)