March 14, 2007

 

UK investigates H-type BSE

 

 

British veterinary authorities are carrying out research of a single case of H-type Bovine Spongiform Encephalopathy (BSE) that was found in the UK in 2005.

 

The incidence was discovered during routine research carried out by the Veterinary Laboratories Agency (VLA).

 

This form of BSE has already been identified in several other European countries as well as in Japan, Canada and the United States.

 

The cow died on a farm in Dumfries and Galloway in Scotland at 13 years of age. The carcass was sampled and tested for BSE in accordance with EU requirements for testing all fallen stock aged over 24 months. Test results confirmed the presence of BSE.

 

The carcass was then incinerated and the offspring from this cow were culled in line with current BSE regulations.

 

In August 2006 the VLA began a retrospective examination of brain samples taken from previous BSE cases as part of a research program designed to analyze different types of BSE in the national herd.

 

The aim of the study is to determine whether unusual cases of BSE had, in fact, occurred in the UK in the past. The studies are ongoing; however, this case has been identified as H-type.

 

All forms of BSE are treated identically, therefore no additional action would have been required in this case.

 

The Spongiform Encephalopathy Advisory Committee (SEAC) is to examine all the available data on this case during a discussion of different forms of BSE worldwide at their next meeting on 10 May.

 

Japan, the USA, Canada and several European countries, including France, the Netherlands, Sweden, Switzerland, and Germany, have reported H-type BSE. Japan and several European countries, including Italy, Denmark, Poland, Belgium and Germany, have reported L-type BSE. Both types have been reported predominantly in cattle over 10 years old. In both types, the abnormal prion protein (PrP Sc ) in these animals has different biochemical characteristics to that seen in BSE.

 

Mice experimentally infected with the brains of these animals developed a disease which differs from that seen in BSE infected mice. In two L-type cases where the intact whole brain was studied, the pattern of deposition of PrP Sc in the brain differed from that in BSE.