EFSA publishes two opinions on testing levels for BSE in cattle

The Biological Hazards Panel (BIOHAZ) of the European Food Safety Authority (EFSA) has published two opinions on the monitoring of Bovine Spongiform Encephalopathy (BSE) in cattle in the first 15 countries to join the European Union (EU 15)[1] . Annually around 10 million cattle are tested for BSE in the EU 15. The number of BSE cases detected in cattle in the EU 15 fell from 2,164 in 2001 to 149 in 2007. According to the Panel, if the age for testing for BSE increases from the present 30 months to 36 or 48 months of age for slaughtered cattle[2], less than one BSE case in cattle could be expected to be missed annually in the whole EU 15. If the age for testing increases to 60, 72 and 84 months of age, then fewer than 2, 4 and 6 BSE cases respectively could be expected to be missed in these 15 EU Member States. The Panel also assessed the “at risk” [3] group of cattle and said, that if the age for testing for BSE in cattle “at risk” increases from the current 24 months to 30, 36 or 48 months, then less than one case could be expected to be missed annually in the EU 15. If the testing age was extended to 60 months of age, fewer than 3 cases could be expected to be missed. In addition, the Panel gave advice on age limits for detecting Atypical BSE [4] and any possible re-emergence of BSE in the future. In its assessment, the Panel also noted that the BSE epidemic has been constantly and significantly declining in the EU 15 since 2001.

Since 1994, measures have been in place in the EU to protect human and animal health from BSE These have mainly consisted of the removal of certain organs and parts of cattle (Specified Risk Materials [5]) before human consumption and of a ban on giving feed contaminated with animal proteins to animals (“total feed ban” [6]). BSE monitoring which is the subject of this assessment was set up to assist risk managers mainly in monitoring the evolution of BSE in cattle and thus in assessing the effectiveness of the risk management measures in place.

EFSA was asked by the European Commission to prepare an opinion in order to inform EU risk managers (European Commission, European Parliament and EU Member States) on possible changes to the monitoring regime in the EU 15. An additional question was received from Belgium which extended the scope of this work and which was the subject of a separate opinion. The Panel evaluated BSE monitoring data which had been collected between 2001 and 2007.

The Panel also said that an age limit of 48 months in cattle “at risk” would allow for the detection of a majority of cases, if BSE were to re-emerge. The Panel added however that testing at 24 months for cattle “at risk” would provide an increased sensitivity in detecting a possible re-emergence of BSE and should also allow for an optimised system for early and efficient detection in case a new type of TSE should emerge in cattle.

The Belgian question to EFSA also asked what number of cases would be missed if the EU 15 stopped testing cattle born after 31/12/2003, which is approximately 3 years after the “total feed ban” was introduced. EFSA’s BIOHAZ Panel replied that amongst those animals born in a given year in the EU 15, fewer than 6 cases would be expected to be missed.

The Panel said that it is uncertain whether the current BSE surveillance system provides reliable data on the prevalence of Atypical BSE, as there are uncertainties surrounding the sensitivity and specificity of current tests in relation to this form of BSE. As no Atypical BSE cases have been detected to date in animals younger than 96 months, raising the age for testing from the present 24 or 30 months up to 60 or 84 months would not have a major impact on the detection of Atypical BSE.

[1] Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, The Netherlands, Portugal, Spain, Sweden, United Kingdom.
[2] At present, in the EU, clinically healthy slaughtered cattle over 30 months of age are tested for BSE.
[3] Cattle “at risk” are animals found dead on the farm from all causes, animals slaughtered owing to an accident or other serious or fatal injury and also animals presenting clinical signs of any type of disease before slaughter. Cattle over 24 months of age who are considered to be potentially “at risk” are tested for BSE. [4] Atypical BSE is a type of TSE which has been identified recently in cattle. It has a different prion protein make-up, making it distinct from the so-called “classical” BSE.
[5] Specified Risk Materials (SRM) are the tissues containing the highest risk of BSE infectivity. These are removed as a key element of the EU BSE controls. Various tissues are classified and then consequently removed as SRM either at all ages (e.g. tonsils), over 12 months (e.g. the skull and spinal cord) or at 30 months (e.g. vertebral column) in cattle in the EU. REGULATION (EC) No 999/2001 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL.
[6] The ban on animal proteins in animal feed in the European Union was introduced in a series of measures from 1994 onwards. The “total feed ban” introduced in 2001 saw the prohibition of all types of animal protein, with some exceptions, from the animal feed chain. REGULATION (EC) No 999/2001 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL.

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