Bluetongue serotype 8 outbreak in Norway

When the outbreak of bluetongue, serotype 8 (BT 8), started in the Netherlands in 2006, the Norwegian authorities and the Norwegian Veterinary Institute carefully followed the development of the disease. Diagnostic methods for detection of BTV had already been implemented, and the staff was skilled to handle an eventual outbreak in Norway.

In 2007 information about bluetongue was distributed to veterinarians, farmers, stakeholders and other people dealing with farm animals.

A surveillance program for vectors was established during the summer 2007, and a surveillance program for cattle started in 2008.

Two dairy herds infected with BTV 8 were detected in the southern part of Norway, in Vest-Agder county, in February 2009. A following comprehensive investigation of the outbreak was carried out before the vector season began late April 2009, and two more infected herds were detected. One of these herds, a beef herd, was situated close to one of the index herds, and the other one, a dairy herd, was located in the neighbouring county, Aust- Agder. Based on the low virus level in the infected animals the Institute of Animal Health in Pirbright estimated the most probable time for infection of the herds to be between August and October 2008.

On the basis of the results from the investigation, monitoring and surveillance, and the fact that the BT-outbreak in Norway was very limited, regarding the number of infected herds and the geographical distribution of the outbreak, it was decided not to vaccinate the ruminant population
against BTV 8.

In the vector seasons 2009 and 2010 comprehensive monitoring and surveillance programmes for bluetongue were carried out in 10 counties in the southern part of Norway, in the restricted zone and in the free zone. The monitoring and surveillance fulfil the criteria laid down in Regulation
1266/2007/EC. No more BTV positive ruminants or herds have been detected during these two years.

The Norwegian authorities therefore conclude with that Norway can be considered free of BTV from 28th of March 2011.