ARS | Publication request: PATHOBIOLOGY OF A HONG KONG-ORIGIN H5N1 AVIAN INFLUENZA VIRUS IN PIGEONS, GEESE, AND EMUS

Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2001
Publication Date: July 14, 2001

Technical Abstract: Objective: To compare the susceptibility of pigeons, geese, and emus to intranasal (IN) inoculation with a H5N1 highly pathogenic avian influenza virus (HPAI). Animals: Four 2-week-old emus (Dramaius novaehollandiae), 11 two-week-old Embden geese (Anser anser), and 10 four-week-old pigeons (Columbia livia) were used. Two to four birds of each species served as sham controls. Birds were intranasally inoculated with a moderately high titer of the A/chicken/Hong Kong/220/97 (H5N1) HPAI virus (HK/220). All birds were monitored for clinical disease. Selected birds were euthanatized and sampling 2-14 days later for influenza virus and histologic lesions. Results: Despite a lack of mortality in geese and emus species, both species developed neurological disease. The HK/220 virus was mostly neuro- and pancreatotropic, causing necrosis and inflammation which corresponded to the presence of viral antigen. Virus reisolation was most consistent from the brain. In contrast, pigeons lacked clinical signs and gross and histological lesions; viral antigen was not demonstrated in tissues; nor was virus reisolated from swabs or from tissues. Conclusions: These results imply that emus and geese are susceptible to infection and disease following IN inoculation with the HK/220 virus. Conversely, pigeons are more resistant and likely played a minimal role in the epidemiology of the H5N1 Hong Kong-like HPAI viruses.