Phylogenetic analysis of canine distemper viruses from red foxes, Greece

Histopathological Characteristics and Expression of CDV-NP Antigen in the Brain of Serologically Positive Spontaneously Infected Red Foxes ( Vulpes Vulpes ) In Western Serbia

Canine distemper virus (CDV) is a worldwide distributed RNA virus that can cause severe disease in carnivore and non-carnivore species. Red foxes are highly susceptible and may act as a reservoir of the virus. As in other wild species, distemper in red foxes can manifest as acute, systemic and chronic nervous form. In the present study, we detected antibodies against CDV among red foxes in Western Serbia, and analyzed histopathologically and immunohistochemically for CDV nuclear protein antigen (CDV-NP) brain samples derived from seropositive animals. Seroprevalence of CDV antibodies was 36.8%. Histopathological changes included gliosis, neuronal degeneration, satellitosis, mononuclear inflammation, demyelination and presence of inclusion bodies. Immunostaining showed a diffuse presence of CDV-NP antigen, mainly in the cytoplasm of astrocytes and neurons. Results of this work contribute to the opinion that red foxes act as a potential reservoir of CDV and underline the importance of routine vaccination of dogs that could come in close contact with these animals. Potential active surveillance program would give a better insight in the degree of CDV infection in wildlife.

RECENT CHANGES IN INFECTIOUS DISEASES IN EUROPEAN WILDLIFE

Many infectious diseases originating from, or carried by, wildlife affect wildlife conservation and biodiversity, livestock health, or human health. We provide an update on changes in the epidemiology of 25 selected infectious, wildlife-related diseases in Europe (from 2010-16) that had an impact, or may have a future impact, on the health of wildlife, livestock, and humans. These pathogens were selected based on their: 1) identification in recent Europe-wide projects as important surveillance targets, 2) inclusion in European Union legislation as pathogens requiring obligatory surveillance, 3) presence in recent literature on wildlife-related diseases in Europe since 2010, 4) inclusion in key pathogen lists released by the Office International des Epizooties, 5) identification in conference presentations and informal discussions on a group email list by a European network of wildlife disease scientists from the European Wildlife Disease Association, or 6) identification as pathogens with changes in their epidemiology during 2010-16. The wildlife pathogens or diseases included in this review are: avian influenza virus, seal influenza virus, lagoviruses, rabies virus, bat lyssaviruses, filoviruses, canine distemper virus, morbilliviruses in aquatic mammals, bluetongue virus, West Nile virus, hantaviruses, Schmallenberg virus, Crimean-Congo hemorrhagic fever virus, African swine fever virus, amphibian ranavirus, hepatitis E virus, bovine tuberculosis ( Mycobacterium bovis), tularemia ( Francisella tularensis), brucellosis ( Brucella spp.), salmonellosis ( Salmonella spp.), Coxiella burnetii, chytridiomycosis, Echinococcus multilocularis, Leishmania infantum, and chronic wasting disease. Further work is needed to identify all of the key drivers of disease change and emergence, as they appear to be influencing the incidence and spread of these pathogens in Europe. We present a summary of these recent changes during 2010-16 to discuss possible commonalities and drivers of disease change and to identify directions for future work on wildlife-related diseases in Europe. Many of the pathogens are entering Europe from other continents while others are expanding their ranges inside and beyond Europe. Surveillance for these wildlife-related diseases at a continental scale is therefore important for planet-wide assessment, awareness of, and preparedness for the risks they may pose to wildlife, domestic animal, and human health.

Evaluation of a Direct Immunofluorescent Assay and/or Conjunctival Cytology for Detection of Canine Distemper Virus Antigen

Canine distemper is a common and potentially lethal multisystemic disease caused by the Canine distemper virus (CDV). We evaluated the diagnostic performance of direct immunofluorescent assay (FA) and cytology to detect CDV antigen in conjunctival cells compared with an established polymerase chain reaction (PCR) detection assay used as a gold standard for CDV diagnosis. Samples were collected from 57 young dogs presenting with central nervous system signs compatible with distemper disease. Exfoliative epithelial cells were collected from the right and left conjunctiva of each animal using nylon-bristled cytobrushes for cytology and cotton swabs for FA and PCR. For the direct FA, samples were stained with anti-CDV polyclonal antiserum conjugated to fluorescein isothiocyanate and imaged using a fluorescent microscope. Out of 57 dogs tested, 19 were PCR positive (15 positive in direct FA and 4 positive in cytology, including one that was negative by PCR), whereas 37 dogs were negative in all methods. A good agreement was observed between the FA and PCR, with a κ-value of 0.833 (95% CI: 0.678-0.989). Meanwhile, there was poor agreement between cytology and PCR (κ-value of 0.164; 95% CI: -0.045 to 0.373) and a fair agreement between FA and cytology (κ-value of 0.231; 95% CI: -0.026 to 0.487). Our results indicated a poor performance of cytology for the detection of CDV antigen. In contrast, FA is a 100% specific and an adequately sensitive assay (sensitivity: 78.95%, negative likelihood ratio: 0.21, 95% CI: 0.09-0.50) for antemortem diagnosis of canine distemper.