Contamination with Potentially Infectious Tissues

CARCASS CONTAMINATION WITH POTENTIALLY INFECTIOUS TISSUES 

Anil et al. (1999) stunned 60 animals with one of four different types of stunning devices, including a penetrative captive bolt stunner used with and without air-injection, a nonpenetrative captive bolt stunner, and a pneumatic air-injection stunning device. Blood samples were collected for 60 s following stunning, and the buffy coat of the blood was assayed using an enzyme-linked immunosorbent assay (ELISA) for presence of Syntaxin 

1-B and Annexin V (Anil et al., 1999). They reported that CNS tissue was present in the jugular venous blood of 4 of 15 animals stunned using a pneumatic air-injection captive bolt sturmer and 1 of 16 animals stunned 

In abattoirs arormd the world, beef carcasses are normally split laterally down the center of the vertebral column, usually by use of a circular band saw, to separate them into sides. Carcass splitting disrupts, severs, and spreads the spinal cord tissue along the vertebral column of a carcass. Additionally, carcass splitting saws accumulate spinal cord tissue inside the saw housings during the splitting process and spread that CNS tissue to the split surfaces of subsequent carcasses. 

Helps et al. (2004) slaughtered two female cattle, followed by one male, and then four female cattle and collected swab samples from the split vertebral-column surfaces. Real-time polymerase chain reaction protocols were followed to determine the extent to which tissue from the male carcass accumulated in the splitting saw and was disseminated to subsequent female carcasses. Under simulated abattoir conditions (i.e., washing the saw for 5 s between carcasses and washing the carcasses before collecting samples), these researchers reported that 0.01% of the tissue recovered from the split vertebral-column surface of the final female carcass in the sequence was from the male carcass and that 10% of the tissue remaining in the housing of the saw was from the male carcass. It was concluded from that study that should a BSE-positive carcass be 

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III. CARCASS CONTAMINATION WITH POTENTIALLY INFECTIOUS TISSUES... 

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