Self Assessment: Viral Inclusion Bodies
in Psittacine Birds
Christopher R. Gregory, DVM, PhD1;
H.L. Shivaprasad, BVSc, PhD2; and Raymond P. Campagnoli, MS3;
Kenneth S. Latimer, DVM,PhD3
1 University of Georgia College of Veterinary
Medicine, Dept. of Small Animal Medicine, Athens, GA, USA 30602; 2 California
Veterinary Diagnostic Laboratory System, University of California-Davis, Fresno, CA, USA
93725; and 3 University of Georgia College of Veterinary Medicine, Dept. of
Pathology, Athens, GA, USA 30602
Introduction
Some of the more common viruses that cause intranuclear
inclusion bodies in psittacine bird tissues are avian adenovirus, Pacheco’s parrot
disease virus (herpesvirus), psittacine beak and feather disease (PBFD) virus, and avian
polyomavirus (APV). Experienced pathologists often are suspicious of these infections
based on the morphology of the inclusions; however, definitive diagnosis often requires
confirmation with other techniques such as immunohistochemistry using a virus-specific
antibody, DNA in situ hybridization using a virus-specific nucleic acid probe, and
transmission electron microscopy (TEM).
Photomicrographs of intranuclear inclusion bodies of the
more common viruses are shown below in sections of liver or spleen. Test your
"inclusion body knowledge" by trying to diagnose the correct viral infection. A
correct answer will take you to a link with more information on that virus (courtesy of
Avian Viruses: Function and Control, B.W. Ritchie, ed., Wingers Publishing, Inc., Lake
Worth, FL, 1995). If your choice is incorrect, try again. Finally, a "mystery
case" with a full diagnostic work-up is presented (courtesy of H.L. Shivaprasad).
Now that you’ve tested your "inclusion body
I.Q.," here is a case that fooled even some experienced exotic histopathologists! See
if you can identify the viral infection based upon microscopy alone. Keep trying until you
get the correct answer. Then see the extensive diagnostic work-up needed to identify the
viral inclusions.
This Page Last Updated November 15, 1999 |
