Usage of meat and bone meal in animal, poultry and fish feeds: A survey and risk analysis for the occurrence of bovine spongiform encephalopathy in Bangladesh

BACKGROUND: Bovine spongiform encephalopathy (BSE) is an emerging zoonotic disease of cattle associated with pathological prion protein (PrP(sc)) transmitted via meat and bone meal (MBM). Although Bangladesh did not experience a BSE outbreak but the country could not export animal products to developed countries as has not yet been declared BSE free country by OIE due to lack of scientific risk evaluation for BSE. The objectives were identification of hazard, release and exposure pathways of pathological prion protein through MBM and analysis of risk for the occurrence of BSE in Bangladesh. METHODS: The scientific data were reviewed, hazards were scheduled and surveys were conducted on livestock production system, import of MBM and its use to identify the hazards present in Bangladesh context. The analysis was done by the ‘OIE Risk Analysis Framework 2006 and European Union (EU) Scientific Steering Committee (SSC) 2003’. From the historical reviews, import of MBM and its use was identified, as external hazards. RESULTS: The analysis revealed that these hazards had negligible or moderate risk for the introduction of infectious PrP(sc) as Bangladeshi cattle are vegetarian cattle. No milk replacer was used and use of slaughtered waste in the animal feed industry is absent. Unconsumable bones are processed to produce bone chips, fertilizers and bone meal for poultry feeds. Scrapie was never prevalent in Bangladesh. Therefore, risk from the internal challenge was negligible in Bangladesh for the occurrence of classical BSE. These prevented the propagation of BSE infectivity and eliminated BSE infectivity from the system very fast, if that was present. CONCLUSIONS: It was concluded that introduction of PrP(sc) into cattle population of Bangladesh through MBM was very negligible. Therefore, Bangladesh can be considered as BSE negligible risk country.