Radio Poland's Marcin Matuszewski has the details in his audio report - available in our player (red button above and on the left).
Tests were carried out due to the unexplained deaths of corvid birds, including crows, jackdaws, and magpies, in and around Warsaw since mid-July 2024.
Initially, avian influenza and Newcastle disease were ruled out as causes.
However, some samples have now tested positive for the West Nile Virus (WNV), and these results have been sent to the European Reference Laboratory in Paris for further confirmation.
What is West Nile fever, and how to protect against it?
West Nile fever is a zoonotic viral disease primarily transmitted by mosquitoes, with human infections ranging from asymptomatic to severe. Currently, the risk for humans in Poland is low; however, it is advisable to take protective measures against insect bites and report any dead birds to the appropriate authorities.
"The virus cannot be transmitted between people through coughing, sneezing, or physical contact, which means the current risk of West Nile virus infections in our country is considered very low," the spokesperson for the Chief Sanitary Inspectorate (GIS) told the Polish state news agency PAP.
An expert further noted that the virus is mainly spread by bloodsucking insects, particularly mosquitoes and black flies, with the Culex pipiens mosquito being the most common vector in Europe.
Polish eco-activists, who were the first to bring the matter of corvid deaths across Warsaw to light on social media in mid-July, have their doubts if West Nile Virus is the sole cause, though.
Due to that fact they ordered an independent, crowdfunded set of complex analyses of samples taken from the carcasses collected across Warsaw - and they are expected to publish their findings in following days.
(mp/mm)
Source: IAR/PAP/GIS/YouTube.com/Osmoza