HQ Team
July 17, 2023: One of the highest instances of felines being infected by avian influenza A (H5N1) has been reported in Poland, and the WHO has started an epizootic probe.
The International Health Regulations’ National Focus Point of Poland notified the WHO on June 27, 2023, of unusual deaths within a wide area of the country.
Until July 11, 47 samples have been tested from 46 cats and one captive caracal, of which 29 were found to be positive for influenza A (H5N1).
Fourteen cats are reported to have been euthanized, and a further 11 died, with the last death reported on 30 June, according to a WHO statement.
First globally
“This is the first report of high numbers of cats infected with avian influenza A(H5N1) spread over a wide geographical area within any country.”
“The source of the exposure of cats to the virus is currently unknown and epizootic investigations are ongoing.”
Some cats developed severe symptoms including difficulty in breathing, bloody diarrhoea, and neurological signs, with rapid deterioration and death in some cases.
In total, 20 cats had neurological signs, 19 had respiratory signs, and 17 had both neurological and respiratory signs.
Post-mortem exams on a small number of cats suggest pneumonia.
Surveillance over
No human contacts of A(H5N1) positive cats have reported symptoms as of July 12, and the surveillance period for all contacts is now complete.
The risk of human infections following exposure to infected cats at the national level is assessed as “low” for the general population “low to moderate” for cat owners and the occupationally exposed to H5N1-infected cats, such as veterinarians — without the use of appropriate personal protective equipment.
Genomic analysis of 19 viruses sequenced from this outbreak showed that they all belonged to the H5 clade 2.3.4.4b and were highly related to each other.
The viruses are similar to influenza A(H5N1) clade 2.3.4.4b viruses which have been circulating in wild birds and caused outbreaks in poultry recently in Poland.
Spread of influenza
WHO stated that there were several possibilities for the source of infection, among which the cats could have had direct or indirect contact with infected birds or their environments, ate infected birds, or ate food contaminated with the virus.
Authorities are investigating all potential sources and to date have not ruled out any.
Of the 25 cats for which the information is available, two were outdoor cats, 18 were indoor with access to a balcony, terrace, or backyard, and five were indoor cats with no access to the outside environment.
Seven cats are reported to have had the opportunity for contact with wild birds.
The “WHO continues to monitor the situation and work in close collaboration with the animal and public health sectors, regional agencies, the Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (WOAH), and other partner agencies in Poland.”
