The number of outbreaks of viral haemorrhagic septicaemia (VHS) decreased markedly in 2003 compared to 2002. In Åland Islands, voluntary eradication measures have been successfully conducted and VHS outbreaks occurred at only 2 farms in 2003, compared to 12 outbreaks in 2002. Another outbreak occurred on a rainbow trout (Oncorhynchus mykiss) farm on the western coast of Finland and this area was added to the VHS eradication programme (Commission Decision 2003/904/EC).
In 2003, VHS virus was also isolated from wild lamprey (Petromyzon marinus) caught in the estuary of two rivers in the Gulf of Bothnia, in the Baltic Sea. The isolated virus type differs from that found at rainbow trout farms and is close to the type previously found in herring (Clupea harengus) in the southern Baltic Sea. All virus isolation tests were performed at the EELA.