West Nile Flavivirus Polioencephalomyelitis in a harbor seal (Phoca vitulina).
A 12-year-old male harbor seal presented with progressive signs of neurologic dysfunction including head tremors, muzzle twitching, clonic spasms, and weakness. Lesions included polioencephalomyelitis with glial nodules, spheroids, neuronophagia, ring hemorrhages, and a few neutrophils. Neurons, fibers, and glial nodules were multifocally colonized with intracytoplasmic West Nile flavivirus antigens that were demonstrated using indirect immunohistochemical analysis. Flavivirus on cultured cells also was isolated and was identified by use of monoclonal antibodies and reverse transcriptase-polymerase chain reaction analysis. Clinical signs of disease and lesion morphology and distribution were similar to those of equine West Nile virus infection. Similar to horses, alpacas, humans, dogs, and reptiles, seals can be dead-end hosts of West Nile virus.
Del Piero
F
F
University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA. fdp@vet.upenn.edu
Stremme
D W
DW
Habecker
P L
PL
Cantile
C
C
D000818:Animals; D017809:Fatal Outcome; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D046049:Phoca / Q000821:virology*; D011051:Poliomyelitis / Q000473:pathology / Q000662:veterinary*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013116:Spinal Cord / Q000473:pathology; D014901:West Nile Fever / Q000473:pathology / Q000662:veterinary*; D014902:West Nile virus / Q000235:genetics