Irish food authorities review tuberculosis meat concerns

The report notes that mycobacterium bovis​, the causative agent of tuberculosis in animals used for production of food, accounts for a relatively small proportion of human cases reported in Ireland (2000 - 2004 only 0.9 - 3.3 per cent), and that "human infection with M bovis by the alimentary route is now very uncommon​". However, for a minority of humans infected, tuberculosis can lead to pulmonary disease and, if left untreated, death. The report therefore makes certain recommendations for producers, which include maintaining efforts to control or eliminate tuberculosis in cattle or other animals used for food production. Milk and dairy ​ The report notes that the "critical role of effective and well-controlled pasteurisation​" in ensuring the safety of dairy products must be emphasised and the effectiveness of the pasteurisation process in individual plants should be monitored. Properly controlled heat treatment inactivates M bovis​ and this has had a major impact on reducing the importance of milk as a vehicle of transmission. Programmes for screening milk producing animals have also helped since animals found to be infected are removed and slaughtered, the report said. The two problem areas remaining are the consumption of contaminated, un-pasteurised milk and the consumption of dairy products made from that milk. It is therefore recommended that milk intended to be consumed or processed without prior heat treatment should come from registered herds or flocks that are subject to an official tuberculosis control plan. For cattle this should include testing for tuberculosis every six months, the FSAI reported. Additionally, cheese manufactures using un-pasteurised milk should only source from such herds and flocks. Upon detection of tuberculosis in a group of animals, all cheese made from un-pasteurised milk originating from that herd or flock since the most recent inspection or test, should be regarded as unfit for consumption. Those who work in the dairy industry and at risk groups should be made particularly aware of the potential dangers of un-pasteurised milk. The report also called for the sale of un-pasteurised milk intended for human consumption, originating from all farm animals to be prohibited. Meat ​ The report notes that the transmission of M bovis​ to humans through the consumption of meat has not been widely documented as a public health concern during surveillance for tuberculosis for a number of years. "The risk, if any, from the consumption of meat sold for human consumption following official controls conducted by the competent authority in abattoirs in Ireland is very low,​" the report stated. Therefore, the report recommends that the current policy with respect to controls on the use of beef testing positive should continue. All animals entering the food chain are subjected to ante-mortem and post-mortem inspection. If the animal is clinically healthy at ante-mortem and has no visible tuberculosis lesions at post-mortem the carcass is passed as fit for consumption. If lesions are detected at post-mortem in two or more organs or regions, the entire carcass is considered unfit. However, the report's authors recommend that auditing of the ante and post-mortem inspections of carcasses at abattoirs should be put in place to verify compliance with EU regulations on the control and removal from the food chain of carcasses or parts of carcasses considered unfit because of the presence of tuberculosis or for other reasons. The authors also suggest that research and information gathering on the links between human tuberculosis infection and M bovis​ should be broadened and that the development of validated laboratory methods for the routine examination of various foods for M bovis should be put in place. They note that at present there is not an accepted laboratory process that would permit certification of a food products as 'M bovis-free​' or 'free from risk of transmission of zoonotic tuberculosis​'. Report authors ​​The report was compiled by the microbiology sub-committee of the FSAI Scientific Committee. The Scientific Committee has recently adopted the opinion contained in the report.