Pathogenesis of Influenza in Ferrets

Abstract

Summary A uniform, mild and acute upper respiratory disease was produced in ferrets with influenza A, PR8. The infectious process and systemic manifestations of disease have been described. Infection elicited the local synthesis of interferon and systemic production of antibody. Temporal relationships of increase and decline in interferon and virus titers were similar, whereas antibody first appeared at the time of resolution of disease. Analysis of mean temperature following infection demonstrated hypothermia on day 1 and hyperthermia on day 2. Individuals did not respond consistently in either respect. Concentration of 25 chemical components of plasma or serum was assayed for alteration resulting from infection. Mean change was observed in levels of lactic dehydrogenase, albumin, β-globulin and glycoprotein. Increase in lactic dehydrogenase was not a constant individual characteristic of disease. Erythrocyte sedimentation rate increased in all infected ferrets. This measurement is, therefore, an accurate and simple means of monitoring the disease in individual animals. Mean change was demonstrated in various other hematologic components, but lymphopenia was the only alteration occurring with a high degree of consistency among individuals.