§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what is the number of cases of BSE of each year of age in each year from 1988 to 1996; and what is the number of cases in which the age is not available in each of these years. [18202]
§ Mrs. BrowningThe following table shows the number of confirmed cases of BSE in Great Britain of each year of age from 1988 to 1996 by age and year of clinical onset as at 3 March 1997:
An experiment to compare the relative infectivity of bovine brain to mice and cattle by intracerebral inoculation is in progress.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what proposals he has for the use of the chemiluminescent tests for the identification of cattle with BSE; and if he will make a statement. [18034]
§ Mrs. BrowningThe test referred to is an ELISA—enzyme-linked immunosorbent assay—test carried out on tissue collected post mortem. The test is reported to be able to distinguish between BSE affected and unaffected cattle which have been slaughtered as suspects, but many more samples will need to be tested comparability before 51W it can be shown to be as accurate as the histopathological test currently used to diagnose BSE. We have no plans to substitute this test for our current method of diagnosis.
There is no information available to determine whether this test is capable of identifying cattle infected with BSE but not yet showing clinical signs of disease and as far as is known tissues from such cattle have not been examined.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what research he has evaluated in respect of the involvement of environmental factors in the transmissive, infective or pathological processes of BSE. [18177]
§ Mrs. BrowningThere is no scientific evidence to suggest that environmental factors play a part in the epidemiology and pathogenesis of BSE. It is however recognised that periods of severe weather have given rise to an increase in the short-term report rate. This appears to be related to a general effect of stress bringing on the manifestation of the early symptoms of BSE in cattle.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what research he has(a) evaluated and (b) commissioned in respect of the infective agent from (i) scrapie and (ii) BSE remaining in hay mites. [18135]
§ Mrs. BrowningThe following is a list of scrapie evaluated and non-evaluated research.
52W
Project code Project title Start date End date Evaluated scrapie projects OC9038 Investigation of the role of the embryo in maternal transmission of scrapie in sheep 01/07/92 30/06/95 SE1402 Transmission of BSE and natural scrapie into sheep and goats by intracerebral and oral routes [became SE1418] 01/04/90 31/03/95 SE1403 Strain typing of BSE pathogens in mice, and comparison with strains from natural sheep scrapie [became SE1415] 01/04/91 31/03/95 SE1404 Susceptibility of BSE and scrapie isolates to laboratory facsimiles of rendering practices [became SE1421] 01/04/90 31/03/95 SE1407 Analysis of nucleic acid and differences between control and scrapie/BSE infected animals 01/04/90 31/03/94 SE1410 Sheep PrP Gene studies 01/04/92 31/03/93 SE1701 Studies of natural and experimental spongiform encephalopathies related to diagnosis 01/04/92 31/03/94 SE1706 Identification of BSE and scrapie infected animals by the detection of a urinary metabolite 01/04/92 31/03/95 SE1709 Sensitivity of scrapie-associated fibrils from different breeds of sheep to proteinase K digestion 01/07/92 31/03/94 SE1710 TSE fibril immunolabelling studies 01/07/92 31/03/94 53W
Project code Project title Start date End date SE1712 Production of sera suitable for the development of immunodiagnostic tests for transmissible spongiform 01/04/92 31/12/93 SE1715 Molecular characterisation of a single stranded (SS) DNA observed in scrapie infected hamster and mouse brain 01/08/93 31/07/94 SE1716 Studies of PrP gene of species naturally and experimentally infected with transmissible spongiform encephalopathies 01/04/92 31/03/95 SE1717 Significance of PrP and putative anti-PrP genes on susceptibility to transmission of spongiform encephalopathies 01/04/92 31/03/94 SE1722 The molecular nature of the agents of transmissible spongiform encephalopathies 01/10/94 30/09/95 SE1808 Transmissibility of BSE and natural scrapie to marmoset by stereotoxic intracerebral inoculation of brain homogenate 01/04/92 31/03/93 SE1813 Transmissibility of scrapie to pigs by oral exposure to brain homogenate [became SE1822] 01/04/93 31/03/95 SE1908 Ultrastructural morphological and immunocytochemical studies of transmissible degenerative encephalopathies 01/04/93 31/03/96 SE1916 Morphometric evaluation of Scrapied mice 01/05/94 31/08/95 Non evaluated scrapie projects OC9425 An investigation of scrapie infectivity and PrP genotype in clinically normal cast ewes from infected flocks 01/04/95 31/03/99 SE0213 An epidemiological study of sheep scrapie to determine means of natural transmission 01/04/95 31/03/98 SE0217 Cattle and sheep products audit trail 24/06/96 23/12/96 SE0219 The epidemiology of TSEs in ruminants and assessment of possible associated risk to human health 01/01/97 31/01/00 SE1409 Development of an antemortem test for BSE and natural scrapie infection through the detection of abnormal deposits of PrP 01/04/94 31/03/98 SE1411 Further analysis of nucleic acid differences between control and scrapie/BSE infected animals 01/04/94 31/03/98 SE1412 PrP gene variants and their potential as marker for natural and experimental scrapie susceptibility in sheep 01/04/94 31/03/98 SE1413 Strain-typing of scrapie agent in meat and bone meal 01/01/97 31/12/99 SE1414 Studies on the "species barrier" in scrapie and BSE 01/04/95 31/03/2000 SE1415 Strain typing of BSE pathogen in mice and comparison with strains from natural sheep scrapie [was SE1403] 01/04/95 31/03/99 SE1417 The effect of PrP genotype on the thermostability of scrapie agent 01/04/95 31/03/2000
Project code Project title Start date End date SE1421 BSE and scrapie agent susceptibility to laboratory facsimiles of rendering practices [was SE1404] 01/04/95 31/03/98 SE1422 Practical aspects of inactivation of BSE and scrapie agents [was SE1405] 01/04/95 31/03/97 SE1707 Sensitivity studies of fibril detection techniques used in Electron Microscopy for the diagnosis of scrapie 01/04/91 30/09/97 SE1713 Gain information on use of resistant rams as method of controlling or eradicating scrapie 01/04/92 31/03/99 SE1718 Identification and characterisation of the scrapie agent from a low protein, high infectivity fraction of brain 01/10/95 30/09/99 SE1725 Studies of the enhancement of reproducibility of PrP Scrapie detection after cold storage of scrapie affected tissue 01/04/95 31/03/98 SE1727 Identification of putative NA components of the etiologic agent of the transmissible spongiform encephalopathies 01/06/95 31/05/96 SE1729 PrP gene codon 171 and species susceptibility to scrapie like diseases 01/04/96 31/03/99 SE1734 Approaches to the identification of nucleic acids associated with the transmissible encephalopathies 01/01/97 31/12/98 SE1814 To determine if scrapie can be transmitted by transfer of embryos from ewes infected with scrapie to uninfected ewes 01/10/95 30/09/98 SE1820 Evaluation of techniques to remove spinal cord from sheep carcasses as part of TSE control measures 01/01/97 31/03/97 SE1822 Transmissibility of scrapie to pigs by oral exposure to brain homogenate [was SE1813] 01/04/95 31/03/98 SE1823 Investigation of the role of the embryo in maternal transmission of scrapie in sheep 01/07/95 31/03/98 SE1910 The demonstration and immunostaining of small virus-like particles in experimental scrapie rodent brain 01/04/96 31/12/97 SE1917 Scrapie infection of sheep neural and extraneural cell lines 01/01/94 31/12/96 SE1919 Studies to identify possible homologies between TSEs 01/04/95 31/03/98 SE1920 Ultrastructural, morphological and immunoytochemical studies of TSE 01/04/96 31/03/99 SE1922 Studies of the sensitivity and specificity of methods of PrP scrapie detection in animal TSEs 01/04/95 30/11/97 The Ministry of Agirculture, Fisheries and Food is currently appraising two projects which have been submitted for research funding on the subject of hay 54W mites. The project titles are as listed. These proposals outline work to determine whether hay or feed mites contain the prions—or potential infective agent—of scrapie or BSE.
ZD0416: The exposure of British sheep and cattle to mitesZD0455: Replication of scrapie and BSE prions in mitesThe prioritisation of other research projects will determine whether funding for these proposals will be made available.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what research his Department has evaluated concerning the number of bovine infective units of BSE required per 100 gm of tissue for an inoculated mouse to be reliably expected to develop the disease. [18196]
§ Mrs. BrowningThe principal research so far conducted to determined the concentration of infectivity—titre—in a BSE-affected tissue by assay in cattle is the study to compare the efficiency of cattle and mice for the bioassay of BSE-affected brain. This experiment is incomplete and there are no other studies proposed to assay quantitatively other tissues in cattle.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food what estimate he has made of the amount of infectivity, in infective units which has been spread on the land by bovine faeces. [18198]
§ Mrs. BrowningNo such estimate is available.
§ Mr. HinchliffeTo ask the Minister of Agriculture, Fisheries and Food how many BSE-infected cattle he estimates were consumed in(a) the United Kingdom and (b) the EU by 1 January 1995. [18199]
§ Mrs. BrowningThe article published by Professor Anderson et al, "Transmission dynamics and epidemiology of BSE in British cattle", inNature on 29 August 1996 estimated that 446,000 infected animals entered the food chain before the specified bovine offal ban at the end of 1989, with approximately 283,000 more before the end of 1995. No estimates of the likely numbers of infected animals consumed in the United Kingdom or EU are available.
§ Dr. StrangTo ask the Minister of Agriculture, Fisheries and Food if he will list the methods of disposal that are(a) permitted and (b) currently in operation for (i) specified bovine material and (ii) non-specified bovine material from cattle with bovine spongiform encephalopathy, including the condensate and washwater produced from rendering of such material. [18696]
§ Mr. Douglas Hogg[pursuant to his reply, 6 March 1997, c. 746]: Where animals are compulsorily slaughtered under the Animal Health Act 1981 as being affected with, or suspected of being affected with, BSE, the Animal By-Products Order 1992 (SI 1992/3303) requires the carcases of such animals to be rendered, incinerated or buried. There is no legal requirement for such carcases to be destroyed specifically by incineration.
It has, however, been the Ministry's practice to use incineration whenever feasible. In the early years of the BSE epidemic, incineration capacity was insufficient to deal with all the cattle involved. At that time, some animals were disposed of by burial, a practice noted, without objection, by the Southwood committee. Since 55W 1991, incineration capacity has been sufficient for other methods to be used only very rarely and in exceptional circumstances.
Thus, up to the end of 1991, 50,735 carcases of cattle affected, or suspected of being affected with BSE were incinerated; 6,117 were disposed of—after the removal of heads, which were incinerated—in landfill sites. Since 1991, only four carcases of BSE cases have been buried, on farm—not landfill—where, because of the remoteness of the area, incineration was not deemed practicable. The last of these was in 1995.
The three cases from 1996 described in my answer of 6 March as having been buried were referred to in error. These cases have now been identified as having been passed to the Cental Veterinary Laboratory for research purposes and their carcases were incinerated.
The carcases of cattle slaughtered under the over-30 month scheme, which started in May 1996 and for which cattle suspected of BSE are ineligible, are required by EU Council Regulation 716/96 to be incinerated or rendered and destroyed. The Spongiform Encephalopathy Advisory Committee advised, in June 1996, that it did not regard the incineration of meat and bonemeal and tallow from animals slaughtered under this scheme to be necessary on scientific grounds.