Retrospective study of etiologic agents associated with nonsuppurative meningoencephalitis in stranded cetaceans in the canary islands.
Nineteen natural cases of etiologically undetermined encephalitides in free-ranging cetaceans were studied retrospectively. Histological examination of the brains revealed variable degrees of nonsuppurative encephalitis or meningoencephalitis, characterized predominantly by perivascular lymphohistiocytic infiltrates. A PCR assay was used on brain and other available tissues to detect the presence of morbillivirus, herpesvirus, West Nile virus, Toxoplasma gondii, and Brucella spp. In addition, immunohistochemical (IHC) staining was performed on selected tissues to determine the presence of morbilliviral antigens. Six animals (5 striped dolphins and 1 common dolphin) showed IHC and/or molecular evidence of morbilliviral antigens and/or genomes, mainly in brain tissue. Conventional nested PCR detected herpesviral DNA in brain tissue samples from two striped dolphins. There was no evidence of West Nile virus, T. gondii, or Brucella spp. in any of the brain tissue samples examined. The information presented here increases the number of confirmed morbillivirus-positive cases within the Canarian archipelago from two previously reported cases to eight. Furthermore, a new nested-PCR method for the detection of morbillivirus is described here. Regarding herpesvirus, the phylogenetic analysis performed in the current study provides valuable information about a possible pathogenic branch of cetacean alphaherpesviruses that might be responsible for some fatal cases worldwide.
Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, Universidad de Las Palmas de Gran Canaria, Arucas, Las Palmas, Spain esierra@becarios.ulpgc.es.
Eva
E
Sierra
Athens Veterinary Diagnostic Laboratory, University of Georgia, Athens, Georgia, USA Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.
Susan
S
Sánchez
Athens Veterinary Diagnostic Laboratory, University of Georgia, Athens, Georgia, USA Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.
Jeremiah T
JT
Saliki
Athens Veterinary Diagnostic Laboratory, University of Georgia, Athens, Georgia, USA.
Uriel
U
Blas-Machado
Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, Universidad de Las Palmas de Gran Canaria, Arucas, Las Palmas, Spain.
Manuel
M
Arbelo
Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, Universidad de Las Palmas de Gran Canaria, Arucas, Las Palmas, Spain.
Daniele
D
Zucca
Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, Universidad de Las Palmas de Gran Canaria, Arucas, Las Palmas, Spain.
Antonio
A
Fernández
D000818:Animals; D001921:Brain / Q000473:pathology; D002002:Brucella / Q000235:genetics / Q000302:isolation & purification; D002591:Cetacea; D006564:Herpesviridae / Q000235:genetics / Q000302:isolation & purification; D006651:Histocytochemistry; D007150:Immunohistochemistry; D008590:Meningoencephalitis / Q000209:etiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D018103:Morbillivirus / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D013030:Spain; D014122:Toxoplasma / Q000235:genetics / Q000302:isolation & purification; D014777:Virus Diseases / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000235:genetics / Q000302:isolation & purification