Joint press release from the DWHC, Erasmus MC, Sovon, Vogeltrekstation NIOO-KNAW, VPDC
Usutu virus was recently detected for the first time in the Netherlands but has been circulating in Europe for some time. To-date it has been identified in captive great grey owls (Strix nebulosa) and in living and dead blackbirds (Turdus merula). These findings have been reported by several research organisations including the DWHC and the Erasmus Medical Centre.
Since August, the DWHC has received more than 40 reports of blackbird deaths in the Netherlands, with the increased death rate seen particularly in the Dutch provinces of North Brabant, Limburg and Gelderland. In addition, the University of Utrecht Veterinary School has performed post-mortem examination on several great grey owls and submitted samples from both bird species to the Erasmus MC for Usutu virus testing. Usutu virus has been responsible for die-offs in birds in several European countries and was recently detected in birds in the German region of North Rhine Westphalia on the Eastern border of the Netherlands. Increased mortality has also been reported amongst blackbirds in Belgium.
The virus has also been detected in several live blackbirds in the Netherlands. These birds were sampled as part of a research project run by the Erasmus MC and the Dutch Centre for Avian Migration and Demography NIOO-KNAW that is investigating the prevalence of zoonotic diseases in wild birds in the Netherlands.
The DWHC, Erasmus MC, Sovon, the Dutch Centre for Avian Migration and Demography, and the Veterinary Pathology Diagnostic Centre based at the University of Utrecht, work closely together in order to investigate unusual deaths and monitor the presence of avian disease in bird populations in the Netherlands. In order to monitor the spread of Usutu virus the public are asked to report finding dead wild birds via the website of the Dutch Field Ornithology Centre (Sovon) or the DWHC submission form (in English). In addition, bird ringers working with the Dutch Centre for Avian Migration and Demography will be sampling blackbirds caught across the country in order to track the spread of the disease.
Usutu virus is an arbovirus that occurs in birds and in recent decades has been detected in countries across Europe including Spain, Italy, Croatia, Hungary, Austria, Switzerland, Germany and the Czech Republic.
Usutu virus causes death in song birds and owls with a particularly high incidence reported in blackbirds, house sparrows, (Passer domesticus) and great grey owls.
On very rare occasions Usutu virus has caused disease in humans: it is transmitted by mosquitoes, predominantly those belonging to the genus Culex. In Europe to-date there have been only five human cases of Usutu virus reported, despite large-scale outbreaks in bird populations. Three of these cases involved immune suppressed patients.
Recommendations for handling dead birds are not affected; refer to the FAQ for advice on how to handle cadavers.