February 24, 2012

In the Spotlight: Past Willdife Disease Investigations from EWDA Newsletter

Past Disease Investigation Highlighted in the European Section of the Wildlife Disease Association Bulletin

Progression of a distemper epidemic in Switzerland

During the first half of 2009, the front of a distemper epidemic reached the eastern Swiss border and rapidly spread towards the central part of the country. Numerous red foxes and Eurasian badgers were observed alive during the day time, often without fear of humans, sometimes also circling and trembling and/or showing signs of respiratory distress. Many others were found dead, most of them severely emaciated.

A small number of stone martens, pine martens and Eurasian lynx were also affected. Although no cases were registered in wolves, the local hunting authorities described that signs of wolf presence in Grisons dramatically decreased and this suggested a possible role for distemper in this process.

Distemper was also diagnosed in a domestic dog previously vaccinated against Canine Distemper Virus (CDV), and the infection was shown to be caused by a strain very similar to those of foxes from the same geographical region during the same period, indicating that wildlife was most probably the source of infection.

Suppurative blepharitis and conjunctivitis in a red fox affected
by distemper
Up to October 2011, cases of distemper have been recorded in 21/26 Swiss cantons, however, cases seem to be fewer and the progression of the epidemic front appears slower than during the previous year. Pathological changes associated with the infection and characterization of the involved CDV have been reported by Origgi et al. [See EWDA Bulletin. 2011; 2(8) for reference].

The main pathological changes consisted of broncho-interstitial pneumonia and meningo -encephalitis with syncytial cells, intracytoplasmic and intranuclear eosinophilic inclusions.

To date, both epidemiological and virological investigations are consistent with the spread of an epidemic front from eastern to western Europe, but data do not allow either to exclude the re-emergence of a local strain.

Source: European Section of the Wildlife Disease Association Bulletin. 2011; 2 (8)

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