The relationship between hygiene assessment system audit scores and the bacteriological status of single species red meat abattoirs in the Free State province

Abstract

The Hygiene Assessment System (HAS) is an audit checklist that is used to measure the hygiene status of the abattoir. The final HAS score for individual abattoirs is graded to a sum of 100, and is interpreted as a measurement of the potential risk to public health. Theoretically, the final HAS score reflects the likelihood of safe meat being produced in that specific abattoir on the day of audit. The aim of the study was to test the association between the HAS scores and the bacteriological contamination in six single species high throughput abattoirs in the Free State province. This was done to validate the efficiency of the HAS score as a measure for meat safety and to determine the extent to which HAS audit score and bacteriological tests mirror each other. Each abattoir was visited once and the audit was performed according to official HAS: four carcasses were sampled at four different carcass sites at three processing stations; and ten direct air samples were collected from the slaughter floors. All the abattoirs showed compliance with the meat safety legislation since the total HAS scores ranged from 68 to 94. However, it was found that the effectiveness of HAS audits as a measure of food safety was questionable, since it does not demonstrate the risk/impact of non-compliance. The microbiological analysis for both carcass and air samples included the test for aerobic plate count (APC), Escherichia coli, Salmonella species and Staphylococcus aureus. The APC for the abattoirs ranged from undetectable to 9.9 x 104 CFU.m-2 for carcass surfaces and 0 to 2.4 x 102 CFU.m-3 for bioaerosols. The total count for E. coli, S. aureus and Salmonella species exceeded the national maximum acceptable limits. These results highlight the possibility of the occurrence of foodborne diseases in the human population. In addition the relationship between E. coli, S. aureus, Salmonella spp, APC, and total HAS score, revealed no significant relationship. These findings further justify the fact that HAS audits should not be used as a measure of meat safety. The results also suggest the importance of the inclusion of bacterial tests in meat safety audits because a high HAS score does not signify that meat is entirely safe for human consumption.