In the wake of the 2016 Usutu virus outbreak, surveillance of live and dead blackbird numbers in April of 2017 revealed that the virus is once again active in the Netherlands.This was paralleled by a slight increase in the number of dead blackbirds reported to the DWHC compared to the preceding weeks. According to figures from the bird migration station of the Dutch Institute of Ecology and Erasmus Medical Center, Usutu virus was found in living blackbirds during the period from April-June 2017. At the end of June there was a clear increase in the number of reports of dead blackbirds over a short time period. From the end of June until the 20th July 2017 the DWHC, in collaboration with Erasmus MC, investigated the cause of death in seven blackbirds: Six of these tested positive for Usutu virus. The combination of these findings with the experience of the previous year and the rise in the number of reports of both sick and dead blackbirds, points to a new outbreak of Usutu virus in the Netherlands. The map shows the locations of the findings to be predominantly in the East, Middle and South of the country.
Birds infected with Usutu virus may show one or more of the following signs:
General illness, apathy, puffed-up feathers, gasping for breath, stopping drinking, general weakness (i.e. not flying, flying low over short distances and resting frequently), drooping head and / or wings, and loss of balance. The range of signs depends on which organs (e.g. heart, brain, peripheral nerves) are affected. These signs are not unique to Usutu virus and diagnosis must be based on further testing.
Usutu virus causes deaths amongst blackbirds and some species of owl. Keepers of Snowy owls and Lapland owls are advised to be alert to the risk of infection and are advised to protect birdcages with mosquito nets or to keep birds indoors.
Report the dead bird to Sovon or via the DWHC Submission form.