Design and Validation with Influenza A Virus of an Aerosol Transmission Chamber for Ferrets

Turgeon, Nathalie; Hamelin, Marie-Ève; Verreault, Daniel; Lévesque, Ariane; Rhéaume, Chantal; Carbonneau, Julie; Checkmahomed, Liva; Girard, Matthieu; Boivin, Guy; Duchaine, Caroline

Nasal washes of ferrets housed in cage two were positive 2-4 days after the infection of ferrets housed in cage one. Nasal washes of ferrets housed in cage three were positive 1-4 days after washes from ferrets housed in cage two were found to be positive for influenza. The delay between the influenza detection schedule in ferrets in cages two and three can be explained by a lower virus concentration in the air and the infection route. Indeed, the airborne influenza virus genome concentration was lower in cage three compared to cage two in 19 out of 20 sampling days. Large particles eliminated by the separator likely contained high virus concentrations. The airborne influenza virus genome concentration in cage three reached 5 × 10 2 genomes/m 3 only when influenza virus was detected in the nasal wash of the ferret housed in cage two. Therefore, it is possible that the airborne virus concentration in cage three reached the required concentration to transmit the infection only when the ferret housed in cage two showed flu symptoms. More experiments would be required to elucidate this phenomenon.