THE INFECTION OF FERRETS WITH SWINE INFLUENZA VIRUS

Area of Science:

• Virology
• Infectious Diseases
• Comparative Pathology

Background:

• Swine influenza virus (SIV) was previously shown to be pathogenic in ferrets.
• Further research is needed to understand SIV pathogenesis and host responses.

Purpose of the Study:

• To confirm SIV pathogenicity in ferrets.
• To investigate the effects of ether anesthesia on SIV infection severity.
• To assess SIV stability during storage and ferret passage.
• To evaluate cross-neutralization between swine and ferret immune sera.

Main Methods:

• Intranasal inoculation of ferrets with SIV.
• Administration of SIV under ether anesthesia.
• Storage of SIV in glycerol at refrigerator temperature.
• Serial passage of SIV through ferrets.
• Neutralization assays using swine and ferret sera.

Main Results:

• SIV is pathogenic in ferrets, causing severe, potentially fatal pneumonia, especially under ether anesthesia.
• SIV retained pathogenicity for ferrets after 75 days of storage in glycerol.
• SIV remained virulent for swine after 16 serial passages in ferrets.
• Serum from recovered pigs and ferrets neutralized SIV for both species.

Conclusions:

• Ether anesthesia exacerbates SIV-induced pneumonia in ferrets.
• SIV is stable under prolonged storage and extensive ferret passage.
• Cross-protective immunity exists between swine and ferrets against SIV.