Twelve fur farms in Finland have now been affected by H5N1 avian flu outbreaks.
As a pandemic preparedness step, two UK virologists call on governments to eliminate mink farming.
H5N1 avian flu has been detected on 5 more fur farms, including one housing silver foxes.
Surveillance in people who had contact with the sick cats found no illnesses, and the WHO said the risk is low to moderate for that group.
The two people had no symptoms and were exposed to sick poultry at different farms.
Blue fox are the most common fur animal farmed in Finland, and officials say wild birds are the likely source of the virus.
Though the virus hasn't shifted its preference to mammalian cells, scientists see some changes that could enhance replication and allow binding to human-like receptors.
The Florida Department of Health reported 2 more local malaria infections, raising its total to 6.
The overall threat remains moderate and is similar to earlier viruses that belong to the same clade.
Scientists say they found the virus in one of five submitted chicken meat samples that the cats ate.