Tissue Tropism of a Strain of Influenza a Virus in Ferrets

Abstract
The study dealt with the occurrence of febrile reactions and with the multiplication of virus in different tissues of the respiratory tracts of ferrets following infection with the Cam strain of influenza A virus. All animals were infected by the intranasal route while under anesthesia. No evidence for multiplication of the virus in the lungs was obtained either during ten serial passages in ferret nasal mucosa, or during five passages in ferret lungs; the latter procedure was made possible by alternate passages in eggs. The results as a whole indicate that at least some strains of influenza A virus are non-pneumotropic agents in ferrets. The results also suggest that fever produced in ferrets by the intranasal inoculation of large amounts of influenza virus is related to the toxic properties of the virus particles rather than to processes involved in multiplication of the virus.