Country veterinarian Bjørn Harlou on the Faroe Islands believes that the disease could have arrived in Fuglefjord from the Shetland Islands by a boat that has since pumped ballast water out into the harbour in Fuglefjord. Another possibility is that herring or wild salmon has carried the infection.

The largest marine farming company on the Faroe Islands, Vestlaks, owns the installation in Fuglefjord. The installation contains one million fish. The average weight for the fish is 1 kilo and they have a total harvesting value, as 3-kilo salmon, of NOK 70-80 million.