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Meat inspector! Whither goest thou?
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The l'ete~qnauJourna11997, 154, 91-92
Guest Editorial Meat Inspector! Whither Goest Thou? The original objectives of post moslem meat inspection included the identification of lesions associated with infectious diseases which posed a risk to the health of farm animals and humans, and to remove the affected tissues fi'om the food chain. The major role of meat inspection today is to remove lesions which make meat unattractive, but not necessarily unsafe, for human consumption. It is a time consuming activity, and its value has been questioned in recent ),ears, particularly as the current techniques for inspection involve handling and cutting of carcasses and offal which increase the risk of contamination with foodborne pathogens. Consequently, less inspection would result in less carcass handling and less incision of tissues; an obvious hygiene benefit. Does meat inspection, in its present form, provide any benefit to the consumer or producer? Could it be replaced by one or more effective systems of quality assurance based on risk assessment? As highlighted by Dax4d Edwards and his colleagues in this issue of the Journal there is, unfortunately, no simple answer to these questions. Clearly, traditional organoleptic meat inspection cannot identify healthy animals infected with important zoonotic pathogens such as the campylobacters, brucellas and salmonellas, and different control strategies are required for these agents. Those suggested by Edwards et al. involve monitoring live animals and include: serological testing, examination of individual animals or herds, examination of farm records (treatment and movement) and their control in, or eradication from, individual herds or regions. For any disease the ultimate control measure is eradication and several, such as brucellosis, footand-mouth disease, swine fever and Newcastle disease, have been eradicated from many countries, although 'breakdowns' occur from time to time even in the best regulated societies! However, disease eradication is hugely expensive, as illustrated by recent experience in the UK with bovine spongiform encephalopathy (BSE). The BSE crisis also 1090/0233/97/050091-02/$12.00/0
illustrates the importance of several criteria necessa D, for effective disease control, namely a thorough understanding of the pathogenesis and epidemiology of a disease and the means for making an accurate diagnosis. Enormous resources have already been allocated to controlling BSE, and only time will tell if the money has been spent wisely, since the control programmes have been instituted before satisfacto W answers were mMlable for these questions. Ma alternative form of eradication is the production of specific pathogen-free herds. This approach has obvious financial advantages for pathogens which reduce the productive performance of animals, for example, the mycoplasmas. However, as with infectious agents which are candidates for eradication on a national scale, those suitable for eradication from individual herds must have certain key features, such as species specificity and known and controllable routes of transmission. A characteristic of many of the foodborne pathogens is that they are carried by many species, making them less suitable for herd or regional eradication. Also, the risk factors for many of the pathogens, and this includes the campylobacters and salmonellas, are not fully understood and may be complicated by the involvement of wildlife species. There is evidence from Denmark, however, which indicates that it is possible to reduce the prevalence of salmonella infections in pigs using extensive serological testing, in this case by enzyme-linked immunosorbant assays (ELISA) of antibodies in fluid collected from meat, followed by the institution of control measures both on affected farms and in the slaughterhouse. Obviously, initiatives of this kind are to be welcomed, although such control programmes cannot be embarked upon lightly as they require the support of all sectors of the industry and the Government, who, between them, will have to provide the financial support for staff and laboratories, and, if necessary, the cost of compensation. The examination of animals on the farm might © 1997 Bailli6re Tindall
92
THE VETERINARYJOURNAL, 154, 2
a p p e a r to be an attractive alternative to inspecting carcasses and offal in abattoirs. However, there is evidence that this a p p r o a c h may well not succeed since exhaustive m o n i t o r i n g o f the health status o f lambs d u r i n g rearing was ineffective at identifying individuals which had lesions visible to the meat inspector (e.g., G r e e n et al., 1997). T h e findings o f this study indicate that re-orienting the scope o f ante mortem inspection, and consulting health and p r o d u c t i o n records, may be o f relatively little assistance to the inspectorate based in the abattoir. Paradoxically, the results o b t a i n e d may only serve to identify 'high risk' g r o u p s which require m o r e intensive post mortem inspection, r a t h e r than less. Meat inspection, albeit principally an e n d product testing p r o c e d u r e , is an integral part o f both quality assurance and quality control systems, and it is essential that gross inspection o f carcasses c o n t i n u e s in some form so that c o n s u m e r s are not sold meat which is ' n o t o f the nature, or substance or quality d e m a n d e d ' . Two o f the questions at issue are ' ~ o should do it?' and 'Who should pay for it?'. Should it be up to the slaughterhouse o p e r a t o r s to oversee the schelne so they do not fall foul o f legislation c o n c e r n e d with c o n s u m e r p r o t e c t i o n or should it be the responsibility o f those agencies that are c o n c e r n e d with f o o d safety and animal health a n d welfare? T h e i n t r o d u c t i o n o f penalties on p r o d u c e r s who fail to m e e t certain criteria must be a p p r o a c h e d with caution, particularly if they are apparently d o i n g everything that is reasonably possible. Clearly, things are going to change, as it is the n a t u r e , o f the m o d e r n world. Any changes made, however, must only be instituted after t h o r o u g h scientific e n q u i r y and n o t as a result o f a political whim or some o t h e r shortterm e x p e d i e n t . T h e collation o f the results o f m e a t inspection can provide useful i n f o r m a t i o n o n animal health matters, a l t h o u g h its limitations in this r e g a r d
must be recognized. It provides n o i n f o r m a t i o n on the prevalence o f clinical disease, since sick animals should not be sent for slaughter, n o r i n f o r m a t i o n on diseases that are e i t h e r fatal or leave n o residual lesions following recovery. However, meat inspection does provide an invaluable insight into the prevalence o f some mild or subclinical diseases. Many o f these conditions have, like the poor, b e e n with us since time i m m e m orial, and it is obvious fi'om a welfare point o f view that they should be c o n t r o l l e d on the farm. A d e q u a t e 'feed back' from the s l a u g h t e r h o u s e to the p r o d u c e r , and Iris or h e r advisors, will help define the p r o b l e m . For some diseases, control measures can t h e n be instituted and their effectiveness m o n i t o r e d when carcasses are e x a m i n e d after slaughter. This is an excellent positive use o f the meat inspection service and o n e which is currently u n d e r exploited. Let us h o p e that, in the future, this resource can be harnessed for the benefit o f the farm animal p o p u l a t i o n and also the prospe,'ity o f the farming industry, o n e on which the wealth o f many countries d e p e n d s . M. H. HINTO.Nand L. E. GREI:?N
Department of Veterinary Clinical Sdence, University, of Bristol, Langford, No~Tth Somerset, BS18 7DU, UK
REFERENCES El)WARDS, D. S.,jOHNSTON, A. M. &, MEAD, G. C. (1997). Meat inspection: an over~,iew of present practices and future trends. The VeterinmyJourna1154, 135--48. GR~:F.N, L. E., BERmATL'A,E. & MORGAN,K. L. (1997) The relationship between abnormalities detected in live lambs on farms and those detected at post mortem meat inspection. Epidemiolo~, and Infection (in press)
The l'ete~qnauJourna11997, 154, 91-92
Guest Editorial Meat Inspector! Whither Goest Thou? The original objectives of post moslem meat inspection included the identification of lesions associated with infectious diseases which posed a risk to the health of farm animals and humans, and to remove the affected tissues fi'om the food chain. The major role of meat inspection today is to remove lesions which make meat unattractive, but not necessarily unsafe, for human consumption. It is a time consuming activity, and its value has been questioned in recent ),ears, particularly as the current techniques for inspection involve handling and cutting of carcasses and offal which increase the risk of contamination with foodborne pathogens. Consequently, less inspection would result in less carcass handling and less incision of tissues; an obvious hygiene benefit. Does meat inspection, in its present form, provide any benefit to the consumer or producer? Could it be replaced by one or more effective systems of quality assurance based on risk assessment? As highlighted by Dax4d Edwards and his colleagues in this issue of the Journal there is, unfortunately, no simple answer to these questions. Clearly, traditional organoleptic meat inspection cannot identify healthy animals infected with important zoonotic pathogens such as the campylobacters, brucellas and salmonellas, and different control strategies are required for these agents. Those suggested by Edwards et al. involve monitoring live animals and include: serological testing, examination of individual animals or herds, examination of farm records (treatment and movement) and their control in, or eradication from, individual herds or regions. For any disease the ultimate control measure is eradication and several, such as brucellosis, footand-mouth disease, swine fever and Newcastle disease, have been eradicated from many countries, although 'breakdowns' occur from time to time even in the best regulated societies! However, disease eradication is hugely expensive, as illustrated by recent experience in the UK with bovine spongiform encephalopathy (BSE). The BSE crisis also 1090/0233/97/050091-02/$12.00/0
illustrates the importance of several criteria necessa D, for effective disease control, namely a thorough understanding of the pathogenesis and epidemiology of a disease and the means for making an accurate diagnosis. Enormous resources have already been allocated to controlling BSE, and only time will tell if the money has been spent wisely, since the control programmes have been instituted before satisfacto W answers were mMlable for these questions. Ma alternative form of eradication is the production of specific pathogen-free herds. This approach has obvious financial advantages for pathogens which reduce the productive performance of animals, for example, the mycoplasmas. However, as with infectious agents which are candidates for eradication on a national scale, those suitable for eradication from individual herds must have certain key features, such as species specificity and known and controllable routes of transmission. A characteristic of many of the foodborne pathogens is that they are carried by many species, making them less suitable for herd or regional eradication. Also, the risk factors for many of the pathogens, and this includes the campylobacters and salmonellas, are not fully understood and may be complicated by the involvement of wildlife species. There is evidence from Denmark, however, which indicates that it is possible to reduce the prevalence of salmonella infections in pigs using extensive serological testing, in this case by enzyme-linked immunosorbant assays (ELISA) of antibodies in fluid collected from meat, followed by the institution of control measures both on affected farms and in the slaughterhouse. Obviously, initiatives of this kind are to be welcomed, although such control programmes cannot be embarked upon lightly as they require the support of all sectors of the industry and the Government, who, between them, will have to provide the financial support for staff and laboratories, and, if necessary, the cost of compensation. The examination of animals on the farm might © 1997 Bailli6re Tindall
92
THE VETERINARYJOURNAL, 154, 2
a p p e a r to be an attractive alternative to inspecting carcasses and offal in abattoirs. However, there is evidence that this a p p r o a c h may well not succeed since exhaustive m o n i t o r i n g o f the health status o f lambs d u r i n g rearing was ineffective at identifying individuals which had lesions visible to the meat inspector (e.g., G r e e n et al., 1997). T h e findings o f this study indicate that re-orienting the scope o f ante mortem inspection, and consulting health and p r o d u c t i o n records, may be o f relatively little assistance to the inspectorate based in the abattoir. Paradoxically, the results o b t a i n e d may only serve to identify 'high risk' g r o u p s which require m o r e intensive post mortem inspection, r a t h e r than less. Meat inspection, albeit principally an e n d product testing p r o c e d u r e , is an integral part o f both quality assurance and quality control systems, and it is essential that gross inspection o f carcasses c o n t i n u e s in some form so that c o n s u m e r s are not sold meat which is ' n o t o f the nature, or substance or quality d e m a n d e d ' . Two o f the questions at issue are ' ~ o should do it?' and 'Who should pay for it?'. Should it be up to the slaughterhouse o p e r a t o r s to oversee the schelne so they do not fall foul o f legislation c o n c e r n e d with c o n s u m e r p r o t e c t i o n or should it be the responsibility o f those agencies that are c o n c e r n e d with f o o d safety and animal health a n d welfare? T h e i n t r o d u c t i o n o f penalties on p r o d u c e r s who fail to m e e t certain criteria must be a p p r o a c h e d with caution, particularly if they are apparently d o i n g everything that is reasonably possible. Clearly, things are going to change, as it is the n a t u r e , o f the m o d e r n world. Any changes made, however, must only be instituted after t h o r o u g h scientific e n q u i r y and n o t as a result o f a political whim or some o t h e r shortterm e x p e d i e n t . T h e collation o f the results o f m e a t inspection can provide useful i n f o r m a t i o n o n animal health matters, a l t h o u g h its limitations in this r e g a r d
must be recognized. It provides n o i n f o r m a t i o n on the prevalence o f clinical disease, since sick animals should not be sent for slaughter, n o r i n f o r m a t i o n on diseases that are e i t h e r fatal or leave n o residual lesions following recovery. However, meat inspection does provide an invaluable insight into the prevalence o f some mild or subclinical diseases. Many o f these conditions have, like the poor, b e e n with us since time i m m e m orial, and it is obvious fi'om a welfare point o f view that they should be c o n t r o l l e d on the farm. A d e q u a t e 'feed back' from the s l a u g h t e r h o u s e to the p r o d u c e r , and Iris or h e r advisors, will help define the p r o b l e m . For some diseases, control measures can t h e n be instituted and their effectiveness m o n i t o r e d when carcasses are e x a m i n e d after slaughter. This is an excellent positive use o f the meat inspection service and o n e which is currently u n d e r exploited. Let us h o p e that, in the future, this resource can be harnessed for the benefit o f the farm animal p o p u l a t i o n and also the prospe,'ity o f the farming industry, o n e on which the wealth o f many countries d e p e n d s . M. H. HINTO.Nand L. E. GREI:?N
Department of Veterinary Clinical Sdence, University, of Bristol, Langford, No~Tth Somerset, BS18 7DU, UK
REFERENCES El)WARDS, D. S.,jOHNSTON, A. M. &, MEAD, G. C. (1997). Meat inspection: an over~,iew of present practices and future trends. The VeterinmyJourna1154, 135--48. GR~:F.N, L. E., BERmATL'A,E. & MORGAN,K. L. (1997) The relationship between abnormalities detected in live lambs on farms and those detected at post mortem meat inspection. Epidemiolo~, and Infection (in press)