Image copyright ESB Image caption Roads and floodplains in Norway have been affected by anthrax infection
A festering outbreak of highly pathogenic Hendra virus may have prompted Norway to cancel a Christmas party, researchers say.
So far, 80 people have been infected and eight died, prompting officials to stop the main event this year because of fears over the risk of contamination.
The 2017 event had drawn around 2,500 people to Statia, near Oslo.
Researchers in Denmark and Norway, who have just published their findings in Science, said the killings were sparked by an influx of humans to the infected areas.
“The infections, primarily of young humans, occurred when local farmers went to the area to harvest crops and when young people were visiting this area for holidays,” the authors wrote.
“Both events may have pushed birds that had previously been isolated to these areas out of their communal environments.”
Hendra virus is responsible for almost 300 deaths a year across the world, though some communities have been at risk for longer.
It is most frequently found in the tropical rainforests of northern Australia, but has been confirmed in North West Sweden, North Korea, China, Russia, Vietnam, the US and Northern Europe.
And now, in 2017, two types of bird toad, velella sibirica and angiostrichalis sibirica, turned up in Norway’s lower Erdingärum valley, where the festival had previously been held.
In wildlife, the viral infection can appear in the form of a separate disease in either birds or mammals.
In humans, it is known to cause diseases including dengue fever, encephalitis and fungal infections, as well as killed many birds that were infected and hunted for hunting.
Image copyright Eric Fertot Image caption One of the causes of this year’s outbreak could be driving new people to an area
The research paper said deaths in “the heavily populated city of Oslo likely represent the greatest number of human infections,” as well as the “most energetic killing mode”.
“The traffic of animals from North West Sweden to the delta and the human population visiting the area due to hunting or from work could have caused (germination of) additional infected individuals from the reservoir and a large release of virus particles,” the report said.