Volume 14, Number 12—December 2008
Research
Highly Pathogenic Avian Influenza Virus (H5N1) Infection in Red Foxes Fed Infected Bird Carcasses
Table
Distribution of lesions and influenza virus antigen expression in experimentally infected red foxes*
| Route of inoculation, fox no. | Lesions |
Influenza virus antigen |
|||||
|---|---|---|---|---|---|---|---|
| Lungs | Heart | Brain | Lungs | Heart | Brain | ||
| Intratracheal inoculation | |||||||
| 1 | +++ | – | + | – | – | – | |
| 2 | +++ | + | ++ | ++ | + | +++ | |
| 3 |
++ |
– |
– |
– |
– |
– |
|
| Fed infected bird carcasses | |||||||
| 5 | + | – | – | – | – | – | |
| 6 | – | – | – | – | – | – | |
| 7 | + | – | – | – | – | – | |
*Foxes were infected either intratracheally with highly pathogenic avian influenza (HPAI) virus (H5N1) or by being fed chicks infected with HPAI virus (H5N1); they were examined at 7 days postinoculation. Respiratory lesions, extrarespiratory lesions, or influenza virus antigen expression were not observed in negative-control foxes. –, absence of lesions (no cells expressing the influenza virus antigen); +, mild and focal or multifocal lesions (few cells expressing the influenza virus antigen); ++, moderate and multifocal lesions (moderate number of cells expressing the influenza virus antigen); +++, severe and extensive lesions (numerous cells expressing the influenza virus antigen).