§ Lord Lucasasked Her Majesty's Government:
Whether they are aware of any cases in which maternal transmission of BSE has been demonstrated. [HL1776]
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§ Baroness HaymanWe are not aware of any such cases. SEAC has, however, concluded that there is some epidemiological evidence of maternal transmission at a low level although it did not rule out the possibility of factors of genetic susceptibility.
§ Lord Lucasasked Her Majesty's Government:
Whether any studies are under way to determine how far mice, that express only human PrP with methionine only at codon 129, and such mice which are heterozygous for valine and methionine at this codon, are susceptible to infection with BSE. [HL1890]
§ Baroness HaymanThis has been identified as a research priority by MAFF. A call for proposals to perform these studies has been included in the TSE Research Requirement's Document which was published by MAFF on 4 April 2000. Suitable BSE brain samples have also been supplied to a UK laboratory which has developed such transgenic mice.
§ Lord Lucasasked Her Majesty's Government:
Whether any studies in humans or animals are under way with the object of determining whether infectious diseases and gastrointestinal disorders play a part in determining susceptibility to BSE infection by the oral route. [HL1891]
§ Baroness HaymanMAFF-funded studies are currently under way to look at early disease processes in the guts of mice and cattle following oral infection with BSE. A study of the gut in sheep with natural scrapie is also ongoing in which any signs of infection other than scrapie are being noted together with any association with prion protein.
§ Lord Lucasasked Her Majesty's Government:
Whether it is considered by those investigating the occurrence of new-variant CJD that a sufficient number of cattle with BSE have been strain-typed to provide an accurate assessment of the nature of the presumed infective agent. [HL1931]
§ Baroness HaymanStrain typing would not identify the nature of the presumed agent: it identifies the strain of TSE present. Scientists working in the field have concluded that there is one strain of BSE as identified by mouse bioassay and molecular typing of the prion protein. The link with vCJD was strengthened when it was shown that the molecular typing of vCJD was the same as BSE. The strain of BSE identified by mouse bioassay and PrP typing remains constant when animals other than cattle are infected with BSE. In addition, the lesion profile within the brains of cattle with natural BSE has been monitored in birth year cohorts starting with the 1992 cohort. The lesion profile in cattle has remained constant, indicating that only one strain is present.