Restriction of imports from the Netherlands
Currently, 15 countries outside the European Union (EU) have taken measures to keep Schmallenberg virus out. These are mainly restrictions on the import of live animals, semen and embryos. The European Commission considers such import restrictions unjustified. The disease has a low economic impact and the risks of transmission of the virus through live animals, semen or embryos are low.
Additional testing could provide additional assurances and thus revive trade. However, such tests are costly. Within the EU it has therefore been agreed that member states will not make individual agreements on such additional tests for the time being.
Background information on Schmallenberg virus
In December 2011, a new animal disease was found in sheep and cows in the Netherlands: the Schmallenberg virus. The disease causes congenital abnormalities.
No risk to public health
There is no evidence that Schmallenberg virus can be transmitted to humans. The RIVM investigated over 300 people who work or live at farms where the Schmallenberg virus was found, or whether infection was likely. In none of these people could a passed infection be demonstrated.
Schmallenberg virus has been found in sheep lambs, goat lambs, calves and adult cattle. The disease is new and it is unknown where it originated. However, initial studies indicate that the virus is similar to Akabanevirus, a known pathogen in ruminants in Asia and Australia. Schmallenberg virus is likely transmitted by midges (a type of insect).
In sheep, the virus is characterized by congenital abnormalities in lambs. For example, the animals have a crooked neck, a water head and stiff joints. Most deformed sheep lambs are stillborn. Live-born animals are not viable. The ewes show no signs of disease.
Sick cows and reduced milk production
Infected cattle have diarrhea and fever. The animals also give less milk. In August and September 2011, these symptoms were reported in cows at over 80 cattle farms in the Netherlands. It is assumed that the Schmallenberg virus was the cause of this. Those animals have recovered.
Schmallenberg virus in malformed calves
Since 23 January 2012, the Schmallenberg virus has also been demonstrated in calves in the Netherlands. That the virus would also be demonstrated in calves was to be expected. The animals were infected in the same period as the sheep and goats. The infection was detected later than in lambs because the gestation period of a cow is longer. Also, on sheep farms several lambs are often born at a time, while on cattle farms it is often 1 calf per birth.
Spread of the disease
On the Dutch Food Safety Authority website, there is a summary map with locations of farms where Schmallenberg virus has been demonstrated, and a report showing, for each province, how many farms have been shown to have Schmallenberg virus, how many farms have not been shown to have Schmallenberg virus after investigation, and how many farms are still under investigation.
After a notification, the deformed animals born on the farm will be tested for the presence of Schmallenberg virus. It is possible that the virus will not be found in this test, as the infection has already taken place earlier in the gestation period. In order to be able to investigate whether (parent) animals on the farm have been infected with the Schmallenberg virus before, a test has been developed which will show antibodies against the Schmallenberg virus in the blood.
Do not cull or close farms
The birth of deformed animals is due to an infection that occurred a few months ago. The virus is probably transmitted by insects (midges and possibly mosquitoes). In winter, these insects are not active and the chance of further spread is minimal. Therefore, there is now no reason to cull infected animals or close down farms. The virus is not (European) notifiable or controllable. However, it is being investigated whether the virus is also passed on in other ways.