Deadly bird disease trichomonosis 'spreads to Europe'

A disease that is killing greenfinches Carduelis chloris and chaffinches Fringilla coelebs in the UK has now spread to Europe, scientists report. A paper in the journal Ecohealth confirms that the disease has been found in Finland, Norway and Sweden and is at risk of moving further afield. The disease, called trichomonosis, is caused by a parasite and was first seen in finches in the UK in 2005. Since then, the country's greenfinches have declined by 35% and chaffinch populations have fallen by 7%.

Becki Lawson, a wildlife veterinarian at the Zoological Society for London (ZSL) and lead author of the paper, said: "Trichomonosis has emerged as a very serious threat to these birds, so it is very important that vets and ornithologists collaborate to determine whether we might see further spread and to monitor the impact of the parasite on wild bird populations across Europe."

A deadly disease responsible for a sudden decline in two of Britain's most popular garden birds has now spread to Europe. Trichomonosis, a disease normally associated with pigeons, apparently "jumped the species barrier" and began to affect British finches in 2005. In some areas chaffinch populations fell by a fifth and greenfinch populations by a third.

Now, research published in the journal EcoHealth suggests that chaffinches migrating from British shores to Scandinavia have carried the parasite that causes the disease, infecting birds there. Finches that had died from trichomonosis began to be found in Norway, Sweden and Finland for the first time in the summer of 2008.

The parasite, trichomonas gallinae, has long been known as a cause of disease in pigeons and doves, and in birds of prey that feed on them, but not hitherto in songbirds. It is vulnerable to dryness and cannot survive for long periods outside its host, so transmission of infection is most likely to be through birds feeding one another with regurgitated food during the breeding season; or through food or water contaminated with saliva.

Sources: BBC News, 22 September 2011
http://www.bbc.co.uk/news/science-environment-14974236
The Independent, 22 September 2011
http://www.independent.co.uk/environment/nature/bird-disease-migrates-f…