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The surveillance and control programme for enzootic bovine leukosis (EBL) in Norway 2012.

Åkerstedt J, Norström M, Mørk T. The surveillance and control programme for enzootic bovine leukosis (EBL) in Norway 2012. Surveillance and control programmes for terrestrial and aquatic animals in Norway. Annual report 2012. Oslo: Norwegian Veterinary Institute 2013.

All milk and blood samples tested in 2012 were negative for antibodies against bovine leukaemia virus (BLV).

The aim of the surveillance and control programme for EBL in 2012 was to document freedom from the infection in Norway according to Council Directive 64/432/EEC as amended and to contribute to the maintenance of this favourable situation.

Enzootic bovine leukosis (EBL) is caused by bovine leukaemia virus (BLV), in the genus retrovirus. Most infections are subclinical, but approximately one third of infected cattle older than three years of age develop persistent lymphocytosis, and a smaller proportion develop lymphosarcomas in various internal organs. EBL is classified as a list B disease in Norway and is notifiable to the Office International des Epizooties.

The disease had never been reported in Norway until antibodies against BLV were detected in eight dairy herds in samples collected through the surveillance and control programme in 1995. No new herds have tested positive since 1997, except a single positive bulk milk sample in one herd in 2002, and one blood sample from one of the cows in that herd. After extensive follow up, it was concluded that the positive antibody results were due to false positive reactions.

Free status from EBL was granted to Norway by the EFTA Surveillance Authority in 2007. 

The Norwegian Food Safety Authority is responsible for carrying out the surveillance and control programme for EBL. The Norwegian Veterinary Institute is in charge of planning the programme, collecting the bulk milk samples from the dairies, and performing the tests. Official inspectors from the Norwegian Food Safety Authority collected the blood samples from beef cattle at slaughterhouses.

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NVI authors

Åkerstedt Johan

Forsker, veterinær

Mørk Tormod

Fagansvarlig - storfehelse