Czech birds are threatened by deadly African disease

The outbreak of a dangerous African bird disease is killing blackbirds and other bird species in the Czech Republic. The mosquito-carried Usutu virus has spread to Europe from tropical and subtropical Africa and has been raising the bird toll across the continent. I spoke to Petr Voříšek of the Czech Society for Ornithology and I first asked him to tell me more about the disease.

Blackbird, photo: SonNy cZ / Wikipedia, free domain

“We don’t know all the details about the disease. What we know is that it’s a virus. It’s called the Usutu virus, it comes from Africa and it’s transmitted by mosquitoes.

“The virus is transmitted mostly to birds, but there are also a few cases of the disease being transmitted to humans, but without the deadly consequences. So the most victims, at least here in Europe, are birds, blackbirds in particular.”

Is this the first time you have detected the disease in the Czech Republic?

“The first case of the disease was detected in the Czech Republic in 2011. This is the second outbreak, but we can hardly say the disease has not been here before.”

Could the current outbreak of the disease be connected to the unusually hot and dry summer?

“This is difficult to say, since mosquitoes usually need some water to develop, on the other hand I think it is almost without any doubt that the spread of this disease and other diseases as well is linked to the climate change. So I can hardly say that it is directly linked this hot and dry summer, but is almost definitely linked to climate change.”

Does it pose a serious threat to the local bird population?

Photo: Stephan Mense / Wikipedia / 3.0 Unported

“Again, we don’t have enough information, but what we know from Vienna, where the disease appeared a bit earlier, suggests that at least on the local level, the disease can cause a decline of the local population of blackbird. And of course there are other diseases that can cause a nationwide decline of a whole species.”

So could the disease eventually wipe out the whole blackbird population in the Czech Republic?

“Not yet, but in the case of emerging diseases, we really never know. I think it’s clear from what I am saying that we are still missing a lot of information. The information we have about the occurrence of the virus in the Czech Republic is very limited. People find dead birds, they report them, but we hardly know what caused the death of each individual bird and the analyses are quite expensive.”

“So I would say we need people to report any unusual dead bird, either to ornithological societies or other responsible institutions, that’s the basic thing. And then of course researches should step in and they should focus more on studying these emerging diseases.”