Dozens of cats from different regions of Poland have died in recent weeks after being infected with the H5N1 bird flu virus, the World Health Organization (WHO) reported today.
“This is the first report of a large number of cats infected with avian influenza A(H5N1) in a wide geographical area within any country,” the WHO reports in a statement. The health organization has warned that the H5N1 virus, against which the human population has no immunity, has the potential to cause a pandemic if it acquires the ability to be transmitted efficiently from person to person.
The route of infection to affected cats is unknown at this time. “The authorities are investigating all potential sources [of contagion] and to date have not ruled out any,” reports the WHO.
No cases of people with symptoms of having been infected have been reported. The WHO assesses the risk of infection after being in contact with infected cats as “low for the general population” in Poland. For owners of infected cats and for veterinarians who have cared for cats without proper protective equipment, the risk is rated “low to moderate.”
Poland notified the WHO of abnormal cat deaths in various regions of the country on Tuesday, June 27. Samples from 46 cats were tested over the next two weeks, of which 29 tested positive for the H5N1 virus. The 29 positive samples come from 13 different geographical areas, indicating that the virus is widespread in the country and that the number of affected animals is probably much higher.
Most of the 29 cats that tested positive developed severe symptoms such as neurological abnormalities (recorded in 20 cats), respiratory distress (19) or bloody diarrhea (no data on the number of cats affected). As of last Tuesday, eleven cats had died and another fourteen had been euthanized.
Since the H5N1 virus has recently been circulating in wild birds in Poland and has caused outbreaks in poultry farms, the cats could have been infected through direct contact with infected birds, or through some indirect relationship with the birds. For example, for having eaten food contaminated with the virus. There is no evidence that the virus is being transmitted between cats.
Of the 25 cats for which detailed information has been collected, 23 were domestic cats and two lived outdoors. Among the domestic cats, 18 had access to a balcony, terrace or patio, but the other five did not have access to the outside, so they could not have direct contact with infected birds.
