Salmonella Infections

HL Deb 25 January 1984 vol 447 cc257-79

4.7 p.m.

Lord Rea rose to call attention to the danger to animals and man posed by salmonella infections; and to move for Papers.

The noble Lord said: My Lords, it is my task this afternoon to set the stage for subsequent speakers. This short debate does not concern, as one might surmise from the title, diseases of game fish, however interesting that might be to some noble Lords interested in fishing, and that includes myself. As everyone participating in the debate and others listening are aware, we are considering the problems caused by bacteria of the genus salmonella which can inhabit the intestines of nearly all animals. The genus is named after the American pathologist Daniel Elmer Salmon, who lived from 1850 to 1914, and he first described the culprit. Now, 130 years after his birth, more than 2,000 strains of salmonella have been identified in animals and man.

The leading member of this international intestinal Mafia is salmonella typhi, the causative organism of typhoid fever—a disease peculiar to man, though often spread through food products. Today, however, we are not considering the chief Mafioso himself but a group of bacteria in the same genus, or gang, which can cause food poisoning in man and scours—that is diarrhoea—and abortion in cattle, pigs and sheep, particularly young animals.

There are a number of strains of salmonella which can cause disease, or are carried in both live animals and in man, and are thus classified as zoonoses. Other zoonoses with which noble Lords may be familiar are bovine tuberculosis, which is milk-carried tuberculosis, and brucellosis, also shared between cow or goat and man, about both of which there has been legislation which has been debated in this House and another place. There are many other zoonoses, some interesting but rare, and some of great importance especially in tropical areas—yellow fever, to name one important disease.

The topic of salmonellosis is important because diarrhoeal disease is a world problem, and it appears to be increasing in this country and in some other developed countries as well. According to the Communicable Diseases Surveillance Centre at Colindale there were 14,325 identified cases of human salmonella infection in 1983 compared with only 8.500 in 1979. Every year there are about 40 human deaths affecting mainly the vulnerable age groups—that is, those under five and those over 65, particularly the latter, although it is an important cause of outbreaks particularly in hospitals, more particularly in maternity hospitals.

This figure is a gross under-estimate of the real incidence because only a very small minority of the episodes of gastrointestinal infection are investigated to the extent that a specimen is sent for laboratory identification. This low notification rate of salmonella is partly because the disease is, luckily, relatively mild and usually lasts less than a week, yet it is still the major cause of sickness absence from work, quite apart from the unpleasantness, pain and suffering that it causes. Few attempts to calculate the economic costs are made, but in a recent outbreak in Scotland, in which 31 cases were notified, a costing estimate of more than £6,000 was made which amounts to some £200 per case. If extrapolated to the 14,000 notified cases in the country, this could add up to £2.8 million. Since we know that the identified cases may be only one-tenth of the total, it is possible that we are dealing with over £20 million of economic cost to the country as a whole.

This does not consider the agricultural losses. In agriculture salmonellosis is of considerable importance. For instance, some 4 to 5 per cent. of all calves die. That is, one in 20 to 25. About half these deaths are due to scouring, that is a diarrhoeal disease in which salmonella species are the most important identifiable pathogens. Sheep also suffer from serious scours due to samonella which can also cause abortion in both cattle and sheep. Pigs and other farm animals are also affected.

Salmonella is ubiquitous in the animal kingdom. But of the 2,000 known strains very few concern man and his food animals. Ten strains alone cause about 75 per cent. of the recorded incidents. As I said, some strains cause disease in both man and animals. One of these is salmonella typhimurium, so described because it causes a typhoid-like disease in mice. This is a worrying one because of its ability to develop resistance to most known antibiotics. Other strains can cause disease in man and are carried in animals without causing them very much harm. Most of the salmonellae which are found in poultry fall into this category.

For the purposes of today's discussion I shall confine my remarks to the salmonellae strains which affect cattle and hence dairy products, and poultry, since some 70 to 80 per cent. of the human food poisoning outbreaks can be traced to infections from these two sources—poultry being the commonest. Other noble Lords may have information on salmonella as it affects sheep and pigs; it is still an important economic problem for them but it less often leads to disease in humans.

As far as human disease due to salmonella is concerned, it should be said at this point that adequate cooking of meat, which implies proper defrosting of frozen meat and heat-treatment of milk, renders the product safe. But as long as the animals and poultry carry pathogenic bacteria, there is always a danger, due to human error, that disease can occur. The object of our discussion today is to try to identify ways in which pathways of infection can be reduced, thus reducing disease both in humans and animals.

Inevitably somebody along the line will have to alter their behaviour, and costs will be incurred. As with any other public health measure, they will say, "There is no money. It will ruin us", as the London water companies did after the 1853 cholera outbreak. However, when the health of the people of this country is at stake and legislation is introduced, they have a habit of coming round.

Before considering what can be done to control the problem, it is worth considering the original sources of infection and their spread among food animals. There is existing legislation which aims to control the problem; but, as I hope to point out, we are not sure how effective it is and its application may need to be more rigorous. I refer here to the Zoonoses Order of 1975, the Diseases of Animals (Protein Processing) Order, the Importation of Processed Animal Protein Order and the Poultry Processing Order, all of 1981, as well as various other prior regulations affecting animal marketing and processing. I am not a legal beagle and it is a complicated area. I am sure that when the Minister replies he will be more well versed in this legislation.

Another important consideration is the effect of EC regulations and how our legislation may mesh with these. There are certain areas, apart from these orders and the existing legislation, where new measures may need to be enacted. The problem is highly complex and highly technical and I do not think we can more than skate over the surface of the problem in a debate such as this. We are hoping that the Minister will be able to tell us that the Government also take these problems seriously and might, for example, set up a small working group of experts to look further into the matter and to make more detailed recommendations; and that the Government would act—not sit—on these.

As a first example, I should like to consider salmonellosis in calves. Calves born to dairy cows are separated from their mothers very soon after birth; often after 24 hours or less when they have obtained only a small proportion of the colostrum they need. This is different from ordinary milk, being very rich in globulins, the protein fraction which contains antibodies against disease. It is secreted by the cow for four to five days after birth and gives the calf immunity to the numerous pathogens—bacterial, protozoal and viral—which are present in the environment, during the critical first few weeks when its own immune defence system is immature and not fully functioning.

The male calf, thus vulnerable to infection, is taken to market, often when it is only a few days old, where, if it is lucky, it will be bought directly by a beef producer and go to its new home with minimal stress or mixing with other calves. More commonly, however, it will be bought by a dealer who may take it to another market a few days or a week later, in hope of a profit. The calf is stressed by the journeys and its abrupt weaning and it is brought into contact with other calves from different farms with different bacterial flora. The less healthy the calf, the more likely it is to be resold and subjected to these multiple stresses.

Sometimes these very young calves are sold three, four or five times over in one month. The lorries and pens at the market may be contaminated with the faeces of the previous occupants so that infection of the calf is very likely from these sources as well as directly from other calves from different farms with which they have mixed. It takes only one calf with salmonella typhimurium or salmonella dublin—the two commonest salmonella pathogens in cattle—to initiate widespread infection and this often happens.

Measures to cut down cross-infection in the market could be applied more vigorously. One which the British Veterinary Association is vigorously promoting is a prohibition on the marketing of calves more often than once in 28 days. Their coats could be clipped in an identifiable way at the time of sale so that they could be recognised if they were presented for sale again within the 28-day period. Another measure, apart from careful disinfection of pens at markets, would be the compulsory cleaning out and disinfection of lorries at markets which at present take several lorry loads of calves without being adequately cleaned between loads. Only a minority of markets at present have adequate facilities for this.

A further interesting suggestion is that the farmers or auctioneers offering calves for sale could have a simple haemaglutination test done on each calf which would be able to identify whether the gamma globulin level in their blood was high enough to give good resistance to infection. This level would be provided by adequate colostrum intake from the cow. This would require at least three to four days suckling after birth and before weaning. A better price could probably be obtained for the calf with a satisfactory level, and this would encourage dairy farmers to keep the calves with their mothers for a few days longer. This measure would, I think, appeal to those noble Lords who are interested in animal welfare as well as animal health.

The second example that I am going to take concerns poultry farming and processing. It has been shown that up to 79 per cent. of frozen chickens offered for sale in this country contain potentially pathogenic salmonellae. One may ask how this unpleasant situation has come about. I do not find it altogether reasssuring that proper defrosting and cooking will kill the infection. I hope that other speakers may point out how easy it is for mistakes to occur in cooking and especially in large-scale catering.

The original source of the salmonellae concerned is most often the feedstuff given to poultry. Sometimes the infection is "vertical"—that is, passed from chicken to egg to chick. This type of transmission could be reduced by various methods of treatment of the eggs which hatch into chicks which are subsequently raised for human consumption. Sometimes the infection is "horizontal"—from external source to chicken and from chicken to chicken via faecal contamination.

The villain of the piece is imported, processed, protein feed, against which the 1981 orders that I mentioned were aimed. This product contains animal or fish protein obtained from knackers' yards and other unmentionable sources of animal or fish which are unfit for human consumption. This product often comes from countries where there is an overall protein deficiency in the population, so that the protein that is deemed unfit for human consumption must be very unfit indeed. The archetype of this type of infection is salmonella agona, which first began to appear in this country following the importation of large quantities of Peruvian fishmeal.

The orders that I have mentioned go some way to remove this source of infection, but doubts have been expressed about their effectiveness, especially the adequacy of the sampling requirement for imported feeds. This, it is felt, could be tightened up or the feedstuffs themselves might be required to be treated to render them sterile. This is an area which needs closer examination, as I hope the noble Lord the Minister will agree.

Once the infection has reached the young birds, the intensive methods of rearing lead to cross-infection once the infection has reached the chicks. Although the young birds are not noticeably ill, the infection level is often very high at eight weeks of age—possibly before they, like the young calves in the previous example, have developed fully their immune defence system. If they are left a further four weeks, the infection level becomes very much less and nearly all birds will have eliminated the salmonella bacteria. However, so intensive and competitive is the poultry industry that it is not economic to wait this extra month since maximum growth takes place in the first two months.

But it is in the processing of the slaughtered birds that salmonellae are spread most effectively. Plucking and disembowelling (or cleaning) the dead birds is an obvious area where this can occur since it is very difficult and expensive to sterilise equipment between the processing of each bird. The worst part of the chain, however, occurs in the spin-chiller, in which large numbers of killed and disembowelled birds are immersed in cold water together prior to freezing. It has been shown that infection rates are multiplied several times during the chain of processing prior to freezing.

I think that I have said enough now about the problem. I have learned a great deal myself while doing the groundwork for this debate and I must thank all my informants for the time and hospitality that they have given me. I should particularly like to mention Dr. Gibson of the British Veterinary Association, Dr. Tony Andrews of the Royal Veterinary College and Dr. Rowe of the Central Public Health Laboratories at Colindale. I have been able to give only the bare outline of the subject. For instance, I have not discussed the possible important role of vaccines to prevent infection and the treatment of infected animals or poultry with antibiotics. Other noble Lords are perhaps better qualified to speak on this matter, especially the noble Lord, Lord Swann, who chaired the important committee which looked into the role of antibiotics in agriculture and which reported in 1969.

I think that improved measures to deal with salmonella will also help to cut down other infections which may follow some of the same pathways. I refer particularly to the genus campylobacter which has recently been shown to be even more important than salmonella as a cause of human gastrointestinal infection. In each year since 1981, the number of laboratory isolations of campylobacter has exceeded those of salmonella. This disease can be equally, if not more, unpleasant. Its epidemiology is not yet fully worked out but it is already clear that animal transmission plays a major role in its spread.

I look forward greatly to the contributions of other noble Lords and to the Minister's reply which I hope will indicate the Government's concern and willingness to initiate action in this area, which is of great importance both to the health of animals and humans in this country. I beg to move for Papers.

4.26 p.m.

Lord Winstanley

My Lords, I am most grateful—as, indeed, should we all be—to the noble Lord, Lord Rea, for drawing the attention of your Lordships to this very important and somewhat neglected subject of food-borne infections. I am grateful to him for doing so with such deep professional knowledge and understanding. Perhaps I should say at the outset to the noble Lord that as a professional medical colleague of his I have not, to my knowledge, had close contact with a case of salmonella for a very long time, although I agree with the noble Lord that many cases go undiagnosed. In fact, the last positively-identified case of salmonella typhimurium with which I was concerned arose at Eskdale, very close to the home of the noble Lord's kinsman, the last Lord Rea, who lived there. I hasten to say that there was no connection between the residence of the noble Lord, Lord Rea, and the occurrence of this particular case. I mention it merely so that the noble Lord will know how long it is since I have had personal professional involvement in a case of this kind.

No doubt, as the noble Lord has made clear, there are many lines of defence available to us against food-borne infections, and, equally, in my view—and, I think, in the view of the noble Lord—perhaps the first line of defence, and one of the most important lines, rests in the hands of the veterinary profession. I speak as an honorary vice-president of the British Veterinary Association. I must emphasise the word "honorary" very carefully to make it utterly clear to noble Lords that, while I am very glad to advise them and assist them on matters of their own health from time to time, I am not professionally competent to advise them professionally about the health of their dogs, their cats or even their racehorses. But I keep in close contact with friends and colleagues in the veterinary profession, and I am very glad indeed that the noble Lord, Lord Rea, has brought to the attention of your Lordships' House some of the points made by the British Veterinary Association on this issue. I do not want to go over them again, but I would emphasise one or two.

We are discussing human infections which have resulted from the consumption of contaminated milk, meat or eggs. We must agree, I am sure, that the control of salmonella infection in food animals is, therefore, a matter of the utmost importance. It should be looked after, and we should listen to the advice given to us by the veterinary profession. It seems to me that much of the advice falls into a number of different areas, which the noble Lord himself has dealt with.

Firstly, there are matters to do with the sale of food animals. There is no question at all, I believe, that the presence of sick or scouring calves at markets poses a certain threat. Steps should be taken to ensure that sick calves are not presented for sale, and certainly not presented for sale on a repetitive basis from one place to another. There might be an opportunity for infection being spread. The veterinary profession, I think, would like an assurance that no calf should be offered for sale more than once in any period of 28 days. I believe that the British Veterinary Association has given certain advice to the Ministry of Agriculture as to how that aim might be achieved.

The next important point after the sale is the time of slaughter. That is the time when there are opportunities for infections to be conveyed from one infected animal to another, and when the animals are under stress. The veterinary profession believe that perhaps standards of hygiene in the slaughterhouses are not always maintained with the degree of thoroughness that they ought to be. They maintain that the protein processing order of 1981, to which the noble Lord referred, might be applied with greater rigour than is now the case.

The noble Lord referred to another matter about which the veterinary profession are concerned, and that is the important matter of the transportation of food animals. There are many opportunities here for infections to be transmitted from one animal to another in these circumstances. The Transit of Animals (Rail and Road) Order 1975 surely should be applied more stringently to require the disinfection of all animal transporters after off-loading at a market. That really means that vehicles conveying food animals should not make a number of stops and take new passengers on board, as it were, without some kind of sterilising or cleansing process being conducted in between. The noble Lord made these points very strongly, and I am quite sure that the noble Lord the Minister is well aware of them and that there is discussion about them within his department.

I turn now to the area which is perhaps the last line of defence. Certainly it is the most important line of defence in relation to food-borne infections; that is to say, the whole question of hygiene in the kitchen and in the home. In this country we are very fond of believing that hygiene is something which begins and ends here, and that once you cross the Channel you find immediately that typhoid and cholera are raging. That is very far from being the case. There is no question in my mind that many other countries in Europe have much higher standards of hygiene than we have ourselves. Indeed, there are some Eastern countries which I think are a little more particular about hygiene in relation to animals than we are. But there is this tendency for us to think that we in this country are very hygienic.

I think there have been many changes in recent years, possibly brought about by the fact that many of the men and women in our country can no longer cook. I do not in any sense blame that fact on the feminist movement—there is no element of chauvinism in what I have said—but I do believe that people are eating more and more heated-up food. I think the noble Lord would confirm that the danger periods for the infection of food occur at certain critical temperatures. Food can become infected on the way up in temperature and also infected on the way down. There is a vast difference between eating recooked food which has once again been brought to a temperature at which contaminants and infections and various pathogenic organisms are destroyed, and eating food which, once having been cooked, is allowed to cool and then is warmed up again later.

I think the time has perhaps come when health educationalists should be thinking a little more about reminding our population of the basic elements of human hygiene in the kitchen, in the home and in the cooking process. We have all seen these notices everywhere which say, "Now wash your hands". We take about as much notice of them as we do of the notices which say, "Keep Britain Tidy", and, "Take your Litter Home". Many people take no notice at all of those. So let us not forget that there is a very important role in this field for the veterinary profession and a very important role to be played by all engaged in agriculture, together with the Ministry of Agriculture.

There is also a very important role for the medical profession as and when people contract some kind of food-borne infection. But, fundamentally, the crucial line of defence is in the home, and that is an area which I think in recent years we have come to neglect more and more because of different eating habits and different methods of preparing food which are no longer perhaps so safe as they were in days gone by.

The time has come for a new reminder about hygiene in the home, and I am most grateful to the noble Lord for having given us an opportunity to discuss this important question. It is one of which we often get sharp reminders ourselves in cases of so-called food poisoning. It is not poisoning, but nearly always an infection; and I think the realisation among the British public of the extent to which food can become infected has diminished and is not sufficiently acute. I hope this debate today will have done something to stimulate a greater understanding of the matter.

4.36 p.m.

Lord Swann

My Lords, I, too, am grateful to the noble Lord, Lord Rea, for raising this matter. I am sure, like him and others, that this is quite a serious hazard. When one talks about food poisoning, one tends to think of a few days or weeks of discomfort, and very often no more than that. On the other hand, as the noble Lord, Lord Rea, said, a number of people, although not many, die from it. The reason is usually that the salmonella bacterium has gone out of their intestines and into their blood. One might normally expect that to be controlled by antibiotics but, as the noble Lord mentioned, it is becoming increasingly clear that quite a lot of the salmonella bugs have become resistant to bacteria, and indeed some of them have become alarmingly multiply resistant.

May I quote a couple of instances? I refer to this same tiresome bacterium, salmonella typhimurium, which has a great many different types. Type 204 is resistant to chloramphenicol, the main antibiotic used against typhoid, and also simultaneously streptomycin, the sulphonamides and the tetracyclines; and Type 193 is resistant simultaneously to ampicillin, chloramphenicol, neomycinkanamycin, streptomycin, sulphonamides and tetracyclines.

The situation in one sense has indeed got worse, and it was because some 15 years ago or more this phenomenon of resistance to antibiotics was being noticed that the committee to which the noble Lord, Lord Rea, referred and which I chaired was set up. We did not know as much then as we know now about bacteria and antibiotics, but we knew quite a bit. We realised that a fair degree of antibiotic resistance was inevitable unless you were simply going to stop using antibiotics; and that, of course, is not a practical proposition in much veterinary work, for both welfare reasons and economic reasons.

On the other hand, there are certain uses of antibiotics in veterinary medicine which we looked at rather closely, and we came to the conclusion that they should be much more rigorously controlled. That was the practice, which still goes on, of using small amounts of antibiotics in animal foodstuffs to get better growth. Exactly why small doses of antibiotics give better growth in certain circumstances was not clear, and indeed it still is not clear now. In essence, what we decided to recommend and what was accepted by the Government of the day was that certain antibiotics which had no great therapeutic use in human medicine should be allowed to be used without a prescription, but that those which did have a therapeutic use could be put into foodstuffs only on a veterinary surgeon's say-so, when dealing with the animals that he had under his eye. We were not certain whether this would work, but it seemed to be the only practical method of controlling antibiotics which we thought was a political starter.

At the same time, we made a lot of recommendations about husbandry and hygiene, but the report has generally become associated with the recommendations about antibiotics. A year or two after this report and following various Government actions, the use of antibiotics in animal feedstuffs actually dropped to about half. But such is human nature that within a few years it was back again where it was when we first deliberated on it. Therefore the recommendations were never given a proper chance to work. However, I now think—and so do all the experts in it—that they probably would not have worked anyway.

I became rather forcibly aware of this some three or four years ago. I should explain that Government reports are generally designated by the name of the chairman. My eye was caught by a headline in the British Medical Journal: "Has Swann failed?" A year or so later there was no element of doubt about it. Another headline read, "Why has Swann failed?" More recently still, another headline said, more woundingly than the others, "Need for a new Swann".

The reason that the initiative failed, and perhaps was doomed to fail, was that the other forms of using antibiotics in human medicine and veterinary medicine for therapeutic processes themselves generate a great deal of antibiotic resistance. The second reason relates to the very peculiar—what, for want of a better word, one can only call sexual habits of bacteria. They are not like the sexual habits of any higher animal, but they are complicated. They result in genetic capacities shifting around the population of bacteria with alarming speed and in complicated and now much better understood ways which can all get together and give multiple resistance.

The situation is reasonably under control in this country but it is far from being totally under control. It is very much not under control in a great many countries of the world, particularly in the underdeveloped countries and in a number of the developing countries where, among other things, antibiotics are almost totally uncontrolled and available over any counter if one cares to buy them. But even the highly developed and, one assumes, highly hygienic countries occasionally have major disasters. There was a notable disaster in Philadelphia in the United States. The Americans, being given to doing total costings, came up with a total costing which was alarmingly much greater than the one which the noble Lord, Lord Rea, quoted for Scotland, but the Americans put absolutely everything into the costing. The epidemic of salmonellosis in Philadelphia in the 1960s was reckoned to have cost about £100 million dollars, the equivalent now of much more than £100 million. So there is an economic angle. There is also a very considerable health hazard. With some strains showing increasing virulence and with quite a lot of strains showing multiple resistance to antibiotics, it is by no means inconceivable that there could be major hazards even in this country.

What can one do about this? It is probably too late, and perhaps was always a lost cause, to think that you could do much about it by controlling antibiotics. The only kind of control which might do good would be so drastic and draconian that it would in effect hamstring both veterinary and human medicine. Therefore one comes to the conclusion (both noble Lords have spoken in this sense) that the old-fashioned methods of controlling disease—isolating it where we can, and so on—are what we need to do.

Perhaps I can do no better than quote one very distinguished Fellow of the Royal Society, who was a Professor of Microbiology and who is now Vice-Chancellor of Manchester University, Professor Mark Richmond. This is how he sums up his views on the question. He believes that Swann succeeded by being a failure: The report focused attention on the growing problems of antibiotic resistance and by its failure has forced the opinion that the control of infection by multiply resistant pathogens must be pursued along conventional epidemiological lines and not solely by imposing more stringent restrictions on antibiotic use. Both noble Lords have already referred briefly to the kind of action that can be taken. There is a list of possibilities as long as your arm and I shall not weary your Lordships with the details. Let me, however, return to the article that had as its headline, "Need for a new Swann". I want to quote another veterinary expert. Professor Walton of Liverpool, who concludes another learned article by saying: It may be said in summary that the overall situation with regard to salmonellosis in man and animals is not showing any real improvement. There are still too many people looking only for different salmonella isolates. The time is long past for a full reassessment of all the information available on salmonellosis to enable weak links in the environmental recycling of salmonellae to be identified and rigorously controlled". Some of the "recycling", as Professor Walton calls it, is obvious enough. We have heard about what happens to cows in the market context. Many noble Lords know about what goes on in farms. There is lack of hygiene. Slurry is seeping along public highways from farms. One knows what goes on in slaughterhouses, food packaging factories and so on. Very stringent precautions need to be taken if salmonellosis is not to escape and cause sometimes mild infections but occasionally very serious infections indeed.

A new report of some kind is needed. Of that there can be no question. A new investigation needs to be carried out by experts, in the light of the much greater knowledge that we have now than we had 15 years ago. There are developments in the technical laboratory-science world which need to be looked at. The epidemiology of these infections needs to be investigated. There is also a need to look at the variety of ways in which the disease can be isolated and controlled and possibly dangerous links in the recycling discovered. All this needs to be investigated in the light of present knowledge. How much at the end of the day will depend upon Government initiatives—legislation, orders and so on—I do not know. At the same time, a major educational effort is required by everyone, from the farmer direct to the housewife who cooks the meal. Once again may I emphasise that—though, Heaven help me, it shall not be me—another Government committee ought to look at this problem.

4.48 p.m.

Baroness Fisher of Rednal

My Lords, having listened to the noble Lord, Lord Swann, and my noble friend Lord Rea, I rise with diffidence to speak in this debate. Both noble Lords have dwelt upon what I would call the animal side of salmonella infection. I shall not try to equal their expert knowlege. It would be beyond me. First, I have not had their education. Secondly, some of the words are so technical and so difficult to pronounce that I should get into great difficulties. However, may I emphasise another aspect of the debate—the point Lord Rea mentioned when he began his speech, that salmonella food poisoning is an important cause of sickness in human beings as well as in animals. The noble Lord followed up that statement with certain figures.

May I remind noble Lords that the district councils and the metropolitan districts have a statutory duty to look after food safety for the consumer. This is achieved by the environmental health officers who carry out routine spot checks on all food premises under their control. There is regular monitoring of what they call "at risk" foods by sampling for microbiological levels. There is the closest contact between the environmental health authorities and the Public Health Laboratory Service at Colindale. I understand that the Institute of Environmental Health Officers conduct what are described as cleaner food courses.

I am sure they go a very long way in providing education for food handlers who work outside the home environment. The noble Lords, Lord Winstanley and Lord Swann, emphasised how important it is that housewives themselves should be aware of good food hygiene. Perhaps it would be a sensible proposition to extend that service so that it could be provided to women's organisations and possibly in schools' home economic courses.

There is ample evidence that the type of catering normally arranged in the form of a buffet and sandwiches for those types of gatherings which attract large numbers of persons shows an increase in the risk of salmonella infection; gala days. sales presentation lunches, wedding receptions and. on certain other occasions, even mayoral banquets are instances of events which have been publicised as being those where salmonella infection has occurred.

I am fully aware that strict hygiene conditions are required in food preparation areas and that standards are laid down. I feel sure that they are readily understood by those who are constantly engaged in food preparation for the consumer, but it is of the utmost importance that these procedures are related also, in no uncertain way, to the temporary, untrained catering staff who are very often employed for special occasions. One has to deplore the practice of laying out meals containing turkey and poultry, especially many hours before it will be eaten. That is a very bad practice, and it is one that should not be tolerated under any circumstances because it is bad for public health. Perhaps there needs to be more regular medical surveillance of those food handlers who are engaged in the more vulnerable sections of food preparation. I have given as one example mass catering.

We have just left the festive season behind us—and with it, the public announcements which were made on TV and radio giving advice on the thawing, roasting and storing of the traditional turkey. That advice was very much welcomed by housewives and other consumers—but in my view it needs to be reinforced regularly throughout the whole year and not just at the Christmas season. Frozen poultry now comprises a large part of the food intake of most families. Perhaps the Government will ask the trade to consider displaying suitable notices on the deep freezers which are in most supermarkets these days, emphasising the specific points to remember in the storage, thawing and cooking of poultry.

I know that the turkey and poultry producers' organisations are well aware of the problems of salmonella contamination in respect of their breeding methods. They are most important, but those precautions will be negated if the consumer is not constantly reminded of the correct methods of thawing and cooking, and of refrigeration if the commodity is to be used at a later date.

Turning to another aspect of the debate this afternoon, can the noble Lord who is to reply provide a date by which legislation will become operative making it compulsory for all milk sold in the United Kingdom to be pasturised? Government grants are available to provide financial help to farmers, towards the cost of heat treatment of milk, but my information is that raw milk is still sold. That continuing practice is a cause for concern in respect of the possibility of salmonella infection.

I should like to pose two other questions to the noble Lord the Minister. First, when did the Department of Health and Social Security last update their instructions on the control of food poisoning, and are fresh guidance notes now necessary? Secondly, are food importers subjected to any regulations which need strengthening?

I know that there are many very reputable food importers, wholesalers and retailers, but cheap imports do find their way into this country and to the kind of markets which can be found in one place on one day and in another place the next, and which sell food at what are called "bargain prices". There was a report of a serious outbreak concerning some form of chocolate bars which were imported from Italy, and which caused illness among a great number of children. Those chocolate bars were sold at markets in the south of England. They were removed by environmental health officers and returned to the supplier when the cause of the infection was traced. It is in respect of that kind of food import that I particularly ask the Minister to review whether the regulations are tight enough.

Although I said at the outset that my own knowledge of this subject is not a medical one but purely that of a consumer, I have in fact had a medical involvement as a patient. What I am now going to say follows on the point that I became a patient after visiting Kenya. It may be advisable for people taking holidays abroad and returning to this country with some form of gastroenteritis to consult their GP, so that checks can be made that will rule out any possibility of the human carrier element in salmonella infection. I had to be in solitary isolation for three weeks when I returned from that particular holiday in Kenya.

My noble friend Lord Rea has raised an important issue concerning public health this afternoon. He has shown that deaths from salmonella food poisoning are by no means rare. They occur, as he said, primarily in the older age group and among the very young. It is in respect of the older age group that I wish to comment in support of the remarks made by the noble Lord, Lord Winstanley, regarding the problem of recooked and rewarmed food. It is important that elderly members of the community are told quite clearly that rewarming food is dangerous.

It is an understandable and common practice for many elderly people to cook more food than they need to eat on one occasion and then to store it for another day. It should be emphasised more clearly to those who have greater experience of working with elderly people that it is a dangerous practice, and one that can cause diarrhoea and serious intestinal problems. I am, perhaps, speaking a little too long—especially following the debate we had earlier concerning how long one should speak. I do want to emphasise what Lord Rea said, that salmonella food poisoning is a very unpleasant complaint for the individual concerned, and of course it results in loss of wages. But I would also point out that it is costly in terms of investigation.

This service provided by the local authority, though generally considered a Cinderella service, must be maintained at high levels, and, I would hope, not considered as suitable for cutting as a result of rate reductions. Proper control work and thorough investigation must be undertaken by local authorities when an outbreak accurs. I would appeal to the general public, to medical practitioners, and to hospitals as well, to realise that as soon as outbreaks occur it is important that the environmental health officers come quickly to the scene to try to control the outbreak and find the source. Although environmental health officers sometimes feel that they are a Cinderella service provided by local authorities, let us remember that public health was one of the first and original items of legislation in relation to local government, and although this has changed many times over the last 50 or 60 years their work in relation to control of food standards is still very important and must not be underestimated.

Constant vigilance and constant reminding of good practice in food production and food handling are necessary to reduce outbreaks of food poisoning. Any measures designed to lessen the hazard are worthy of consideration. The noble Lord, Lord Rea, has given us the opportunity of this debate. I hope it has contributed to the realisation of the need for constant vigilance and perhaps to an extra effort on the Government's part to maintain the very good health standards necessary to make quite sure that the consumer has good food produced and good food sold.

5.3 p.m.

Lord Cledwyn of Penrhos

My Lords, like other noble Lords, I am grateful to my noble friend Lord Rea for choosing this subject for debate and for his careful opening analysis. I would also like to pay tribute to the noble Lord, Lord Swann, for his distinguished contribution to the debate. I recall the day that he presented to me the report of his Committee on Antibiotics in Animal Feedingstuffs, as I was the Minister responsible at the time. I had the task of reading his report and absorbing it, and indeed answering questions on it in another place, and subsequently deciding what to do about his report. As he has said, I accepted his recommendations and sought then to implement them. I do not think the noble Lord's report was a failure, as he has sought to say. I believe it was an important report, and if it was overtaken by subsequent developments that does not mean that it was unnecessary or that it failed in any way. As he has advised the House, the time may now be ripe for a new investigation into this subject, and I would certainly be very glad to support him in recommending that to the noble Lord, Lord Belstead.

I was also grateful to the noble Lord, Lord Winstanley, for his important contribution. I always listen to him with great respect because of his authority and experience in these matters, and I much enjoyed his speech. Again, my noble friend Lady Fisher has made what one has come to expect of her, namely, a sensible and a practical speech from the consumer viewpoint. On this occasion I think nothing could be more important. I think her point about the pasteurisation of milk was particularly timely.

It is an opportune moment for the House to consider the incidence of this disease and its implications; and also what may be done to deal with it. I would like to repeat the tribute which my noble friend Lord Rea paid to the British Veterinary Association. They have shown a particular concern in salmonellosis and its spread in Britain, and have publicised ways and means of keeping it under control, and, if possible, eradicating it. They arranged a symposium here in London on salmonellosis some two years ago and over the last few days I have read the report with great interest. Shortly after that symposium, on 18th November 1981, it is interesting to note, we had a short debate in this House on the report of our Agriculture, Food and Consumer Affairs Committee on Poultry Meat Hygiene, which as chairman of the committee at that time I had the honour to open. It was made clear to the committee in evidence, and subsequently in the report, that salmonellosis is a growing danger, and that Government, local authorities, poultry producers, meat processors, and especially the individual consumer must be made more aware of its insidious growth and of the steps which should be taken to counter it.

In the developed world, where medical services and sanitation are good, salmonella food poisoning affects between 10 and 70 individuals per 100,000 of the population every year. The disease is costly to the patient in loss of wages and physical and emotional stress. It is costly to the health and social services for treatment, investigation, and social security benefits, and it is costly to the food industry due to had publicity and sometimes litigation which follows. These losses appear not to have been estimated in this country, but the World Health Organisation report for 1980 states that losses due to salmonellosis in the United States amount to 480 million dollars a year for medical expenses alone. The statistics are disturbing, as I feel sure the noble Lord, Lord Belstead, would agree.

The Public Health Laboratory Services communicable disease report issued on 6th January last records that the laboratory received 14,325 reports of salmonella food poisoning during 1983, the number having risen to that total from 3,898 reports in 1966—a sharp increase. Salmonella food poisoning, although unpleasant, is not usually fatal. My noble friend Lady Fisher referred to deaths, and there are indeed an average of six deaths per 1,000 cases, which occur primarily but not exclusively in persons between 60 and 80 years of age. The majority of human infections are derived from food of animal origin, mainly by the consumption of contaminated milk, meat and eggs. Some outbreaks, however, are the result of person to person spread, and 11 per cent. of outbreaks in hospitals in Scotland were caused in this way.

In the domestic animal a high proportion of infections are non-clinical, although they form an important source of human infections through the food chain. Overt disease is commonly precipitated by stress, such as transport, crowding, exposure in markets, recent parturition, and they can result in heavy losses due to unthriftiness and death. Recovered animals often remain sources of infection for other animals and for man.

As a number of noble Lords have mentioned, poultry are an important source of salmonella food poisoning in man. That was the subject of our report in this House. Over the last six years records show that between 30 and 40 per cent. of food poisoning incidents were caused by poultry. It is well established that between 30 and 70 per cent. of broiler chickens purchased in shops in England and Wales are contaminated with salmonellae. Chickens may derive infection in various ways, but the most important is apparently the feeding of compounded food containing contaminated animal protein, a subject dealt with by the noble Lord, Lord Swann. The problem has been increased by intensification of the industry. Broilers are now slaughtered earlier, before they have had time to throw off their salmonella infections.

As my noble friend said, supported by my noble friend Lord Winstanley, the important point for the consumer to realise is that food poisoning will not follow the consumption of contaminated birds if cooking is thorough. The majority of chickens sold nowadays are accompanied by thawing and cooking instructions which, if properly followed, will result in the destruction of any salmonella present. However, contamination of kitchen surfaces and chopping boards may occur during the preparation of the bird for the oven. Unless these are thoroughly cleaned the cooked bird or other food may be reinfected from the contaminated surfaces. There is an important job still to be done in stressing the dangers to housewives in this country so that simple precautions are taken to reduce the hazard of food poisoning from chickens.

Many cases of salmonella food poisoning occur in catering establishments. Practices such as partial cooking and finishing or reheating can be dangerous, as has been mentioned, and when contamination occurs many more people may be exposed to infection at banquets and other functions than in the home. The initiative of the Institution of Environmental Health Officers in issuing a news release on this subject in December last is to be warmly commended.

My noble friend mentioned legislation. As the House will be aware, important weapons in the fight to reduce salmonella infection are the Diseases of Animals (Protein Processing) Order 1981 and the Importation of Processed Animal Protein Order 1981. These orders, which became effective in April 1982, require all animal-based or fish protein for animal feed to be processed to render it free from salmonellae. This will reduce the flow of salmonellae to farmstock and correspondingly reduce the incidence of non-clinical infections in farm animals.

There are, however, problems in implementing the orders because of the large volumes of food to be sampled and unless this is pursued relentlessly the main effect of the orders will be lost. Protein feed which has been made salmonella-free may, however, be recontaminated during transport and handling so the pelleting of food is an additional safeguard. It has been put to me that this pelleting safeguard should be given greater publicity.

When swill feeding is practised the treatment of swill as required by the Waste Foods Order 1974 will ensure that the food is free from salmonella. The use of irradiation, which I shall mention later, could also be used to ensure that farm animals receive salmonella-free food. Perhaps the Minister will be good enough to confirm that he and the Ministry vets are satisfied that the orders are being implemented thoroughly and that adequate sampling is taking place.

Much work has been done in recent years to reduce the contamination of poultry carcases after slaughter, especially by improvements to the spin chiller, referred to by my noble friend. The exposure of batches of birds to the chilling process in the spin chiller is an obvious cause of contamination unless the equipment is operating properly. Other methods of chilling are not without their problems and there is need for all concerned to continue their efforts to minimise contamination at the processing stage.

My noble friend referred to calves. I merely say that the calf trade is responsible for widespread dissemination of salmonella infection. The dairy farmer often disposes of his surplus calves through the market to rearers. The calves are exposed to stress during transport and some may be exposed in markets several times in as short a time as a week before they find a buyer. I said earlier, and others made the same point, that stress is an important factor in triggering salmonella infection and the marketing of calves is a prime example.

My noble friend has described the steps which the BVA are recommending should be taken. I was interested to read in the Farmers' Guardian of 13th January that auctioneers at the Derby livestock mart have yielded to pressure from the farmers to sell only farmers' calves and not those from dealers. I believe that to be a central point. This is a welcome step to reduce the risk of spreading salmonellosis in calves at that market.

Vehicles used for animal transport have great potential for the spread of salmonella. More stringent application of the Transit of Animals (Road and Rail) Order 1975 would ensure that all animal transports are disinfected after off-loading at a market. It is a fact, however, that over one-third of all livestock markets in Great Britain lack vehicle washing facilities, and so vehicles must be washed and disinfected elsewhere, with consequent risk of spreading infection. This is an unacceptable state of affairs. It is surely the responsibility of all market proprietors to supply such an essential facility as a vehicle wash. I should be grateful if the noble Lord, Lord Belstead, would say whether he agrees with this and can say what steps he has in mind to ensure that these facilities are provided widely in the markets of this country.

Sewage, whether of human or animal origin, contains salmonellae and its careless disposal on agricultural land is liable to spread infection. This has been the subject of investigation at the Institute for Research on Animal Diseases at Compton, Berkshire, following which guidelines to reduce the dangers of application of sewage and slurry to pasture and other herbage crops have been formulated. They should be rigorously followed.

I mentioned irradiation. Looking to the future, the use of gamma-irradiation may have a place in the control of salmonellosis. Irradiation has been used to sterilise the diets of laboratory animals for at least 20 years without any ill-effects being observed in animals as a result. Irradiation can be applied after the food is packed. Thus the chicken inside its plastic bag can be sterilised at a small cost per bird, however heavily contaminated it has become. But the acceptability of this process to the consumer has yet to be ascertained. It must be investigated fully. I understand that the Department of Health and Social Security has a committee inquiring into this and other aspects. The findings are awaited with great interest. Again, I hope the noble Lord can give us some indication of when this report may be expected.

But whatever innovations may lie ahead, it seems to me clear that the damage from salmonellosis could be considerably reduced if the knowledge that is already available is fully used and the existing legislation rigorously applied.

Shortage of staff is too often the reason given currently for shortcomings in applying the law. If that reason is valid, then it is time that the shortage was remedied. Close co-operation between the medical and veterinary staffs and the environmental health officers also is essential. The arrangements for such co-operation which the Zoonoses Order provides are a welcome step in this direction. They must be fully applied. If this debate is to serve a purpose it must be to inspire all concerned to press ahead with determination to cut down the ravages that salmonella can cause. I ask the House to support my noble friend's Motion.

5.19 p.m.

The Minister of State, Ministry of Agriculture, Fisheries and Food (Lord Belstead)

My Lords, I thank the noble Lord, Lord Rea, for raising the problems of salmonella poisoning today. I agree with the noble Lord, Lord Cledwyn of Penrhos, that we have to thank noble Lords for coming to make a series of very well-informed and interesting speeches on a subject which is a cause of worry and concern. It is a subject on which the Government have maintained increasingly close surveillance in recent years.

As has become clear from this short debate, the issues are, however, complex. The problems affect the food chain both of human beings and of a variety of animals and birds, and lead researchers through a maze of causes and effects. It seems doubtful in our modern living conditions whether the complete answer to this problem will ever be found. On the other hand, encouraging progress has been made, especially with poultry. I am advised that the incidence of salmonellae in poultry reported under the Zoonoses Order has been reduced from 1,784 incidents in 1980 to 664 in 1983. We shall have to continue chipping away within the limits of available resources. Certainly there can be no prospect of significant further progress being made without parallel action being taken by the food industries and individuals concerned in trade in human and animal foodstuffs. These are all matters which have been mentioned during the past hour and a half.

I wonder whether I may, literally in the space of a minute, follow the noble Lord, Lord Rea, who at the beginning of the debate mentioned the current legislation, by mentioning it again briefly at the end. The principal instrument is the Zoonoses Order 1975 made under the powers available in the Animal Health Act. For this purpose, I should explain that zoonosis is a disease transmissible from animals or birds to man. The order provides powers to control salmonellosis in animals if there is a serious threat to human health. As your Lordships have made clear that you know, the other orders are those relating to protein processing. There is the domestic order and the importation order, but each has the same objective—to minimise the risk of salmonella infection being transmitted through animal feeding stuffs. I hope that what I have said follows the noble Lord, Lord Rea, in setting the scene.

In talking about legislation, the noble Lord asked me whether I would say a word about how the European Community meshes in with all this. The situation in regard to animal health legislation in general is that the United Kingdom participates in the Standing Committee in Brussels which formulates European Community directives, regulations or recommendations. As such, we have the opportunity of expressing our views and tailoring our legislation to suit our particular circumstances. That applies equally to legislation applicable to meat hygiene.

The noble Lord, Lord Cledwyn of Penrhos, asked me whether the Government believed that the work of monitoring and sampling under both the orders was being carried out effectively. I have some details on that but I shall not weary your Lordships with them now. My answer is simply, yes. I am absolutely convinced from what I have read that good work is being done. In particular, what I have noticed from the advice that I have received is that there is a decline in the number of exotic stereotype incidents in food animals since the importation order took effect.

I was grateful to the noble Lord, Lord Cledwyn, for mentioning the specific arrangement which is made under the auspices of the Zoonoses Order, under which local liaison groups have been established, comprising directors of public health laboratories, medical officers for environmental health, environmental health officers and nominated members of the State Veterinary Service. Thus we have an arrangement under the 1975 Order to ensure the fullest possible exchange of information at what may best be termed working level. As a previous Minister of Agriculture, the noble Lord also expressed the hope that the veterinary and medical services build upon that statutory basis. I believe that they do indeed. Furthermore, all incidents of salmonellosis in animals reported under the Zoonoses Order to the State Veterinary Service are notified to the medical and environmental health authorities.

The noble Lord, Lord Rea, spoke specifically about salmonellosis in calves and calf marketing, as did other noble Lords. Although I am advised that salmonellosis in calves has little impact on human health, it is a serious and increasing animal health problem. But, as is so often the situation, the answer is not clear-cut. The Government agree that the notion that the prevalence of infection might be reduced through introducing a limitation on the number of times calves may be marketed within a given period—and the noble Lord, Lord Winstanley, mentioned 28 days as being the right kind of period—is good in principle. However, the problems of calf identification and enforcement in markets are equally apparent. I should like to give an assurance this afternoon that this is an issue which the State Veterinary Service has already discussed with the British Veterinary Association. The problems of identification to which I have referred remain to be further considered. The Farm Animal Welfare Council also is currently considering the question of the repeat marketing of calves.

In this context, both the noble Lords, Lord Rea and Lord Winstanley, referred specifically to the cleansing and disinfection of lorries, as did the noble Lord, Lord Cledwyn, but he carried the argument on to whether the correct facilities are provided in the markets for disinfection. So that there is no misunderstanding, I ought to make it clear that it is an offence if any vehicle used to carry farm livestock is not cleansed and disinfected afterwards. That must be done as soon as practicable after the unloading of the last animal and in any case before any animal or carcase is subsequently loaded into the vehicle. Local authorities are the bodies responsible for enforcing these provisions. As so often in this difficult field, the means to improvement is by underlining the need for enforcement of the rules. I very much hope that this debate will assist in that objective.

On the point of the noble Lord, Lord Cledwyn, I would say that subordinate legislation under the Animal Health Act provides that cleansing and disinfection of markets and lorries should be undertaken to minimise the risk of animal disease and that the appropriate facilities to undertake cleansing should be available. Again, local authorities are responsible for the supervision of this work. The noble Lord asked me whether the Government were satisfied. We are not, but constant efforts are made to improve market facilities within the financial and physical constraints—for instance, the limitations of the site in question in a particular case. In addition to the efforts of local authorities, members of the veterinary profession, and in particular those belonging to the State Veterinary Service, are undertaking all the time a supervisory function. I assure the noble Lord that this is a matter which we keep constantly in mind.

I wonder whether I may turn to the subject of salmonellosis in poultry. Before I came to this debate I thought that that was perhaps the most common form of the danger of salmonellosis infection. I was particularly pleased when I discovered that there had been this improvement in its incidence which I mentioned to your Lordships at the beginning of my speech. I think it is fair to claim that at least part of the improvement in the situation is the result of a number of measures which have been taken. The Ministry of Agriculture has promoted a development farm project on S. hadar in turkeys which enabled control methods to be developed in breeding flocks, for instance, by the introduction of special nest boxes and improved methods of hygiene.

Secondly, the industry has been very ready to agree codes of practice in its work. In addition, the Department of Health and Social Security has publicised the need to ensure the thorough cooking of poultry meat—a matter which was mentioned by the noble Lord, Lord Winstanley, among other noble Lords. It is now common practice for frozen poultry to be labelled with cooking instructions. Indeed, in 1977 the DHSS issued a health notice and local authority social service letter on the safe preparation of turkeys. I have already referred to the work being undertaken on protein processing.

Every noble Lord in the debate has spoken on aspects of salmonellosis in human beings. The figures that I have are a little different from those of the noble Lord, Lord Rea. Mine show that in 1982 there were nearly 14,000 known English cases of food poisoning from all causes originating in England. I admit that this was more than in 1981 and 1980 but it was less than in 1979. Overall there has been a slight increase in the number of cases due to S. Typhimurium and to other salmonellae, which is of course the most common food poisoning organism.

I listened with great interest to the noble Lords, Lord Winstanley and Lord Cledwyn, and the noble Baroness, Lady Fisher, who identified hygiene in the home as a crucial factor in the debate. Education of food handlers and kitchen personnel in good food hygiene was one of the three lines of attack on the problem of control of human salmonellosis suggested in the World Health Organisation conference on food poisoning in 1980. The noble Baroness asked when did the Department of Health and Social Security last update its advice on food poisoning. I think I am right in saying that that was done in 1982, when the department published a revised edition of Memo 188/MED on, Food Poisoning—The Investigation on Control of Food Poisoning in England and Wales, as guidance for medical officers for environmental health officers and other medical personnel. The Institute of Environmental Health Officers has also published guidance, and it holds courses on food hygiene.

With respect to the noble Baroness's warning about precautions being particularly necessary at large gatherings of people when untrained staff are involved, I would point out that the World Health Organisation booklet on mass catering, by Dr. Charles of the DHSS, is intended for health officials who may have little knowledge of commerial catering, and for food, trade and other officials and representatives of commercial interests who may have little knowledge of public health.

In his speech, the noble Lord, Lord Rea, referred briefly to the economic aspects of this whole subject, and the Government certainly agree that there are indeed economic aspects. As your Lordships will probably be aware, a World Health Organisation working group meeting held in Trier in September 1981 produced a report on Economic Aspects of Communicable Diseases. In that discussion, the economic aspects of salmonellosis were given particular emphasis and further areas for future research were outlined.

Before I conclude my remarks I should like to try to answer one or two questions with which I have not yet dealt. The noble Lord, Lord Swann, who I realise has done very valuable work in this field, made a most interesting speech, and I wish that I could be more forthcoming in the reply that I have to give him. I fully appreciate the noble Lord's commitment on the issues which he raised. The difficulty is that though we agree with so much of what the noble Lord says, we are most hesitant about the appointment of a new committee to look at the subject. As I have tried to indicate in my remarks, we believe that the problems associated with salmonella infection are of a continuing nature and clear-cut solutions are not possible. We have to do our best to try to press forward on all fronts. But the nature of the problems, as opposed to their solution, is not unclear. It will certainly be possible for consideration to be given by the Government and other organisations concerned—notably the British Veterinary Association—to such matters as the use of antibiotics in animals and the questions of resistance to them which arise. As I have already said, we are considering whether any steps can be taken in relation to calf marketing practices.

Without going into any detail, and, incidentally, without in any way trying to reflect criticism on much of the admirable and extremely hard work that goes on in our slaughterhouse systems, I should like to mention that, at the request of the Meat and Livestock Commission, the Government are planning to set up a thorough review of the meat inspection system.

The noble Lord, Lord Rea, and other noble Lords, mentioned the spin chiller system in poultry slaughtering. I should like to say that the Poultry Meat (Hygiene) Regulations 1976 were, as I am sure the noble Lord knows, amended in 1979 to prescribe conditions which must be satisfied when poultry carcases are chilled in water. The spin chiller is such a method of chilling poultry. Published work shows that the improvements prescribed in the amending regulations have dramatically reduced cross-contamination occurring in the process.

The noble Baroness, Lady Fisher, asked me a direct question about raw milk. It is a fact that the arrangements for the selling of raw milk were changed in 1980, when the Government took the view that those people wishing to purchase raw milk—green top milk—should be allowed to do so, provided that they were aware that they were buying untreated milk. Since 1983 virtually all cows' milk sold for human consumption in Scotland has had to be pasteurised. It is the intention in England and Wales to prohibit the sale of raw milk through outlets such as schools, shops, and institutions from May 1985. It is believed that these measures will significantly reduce salmonella infection in humans from this source. I know that I have not answered two of the questions asked by the noble Baroness, and perhaps I may write to her.

Finally, I wish to take up the point which the noble Lord, Lord Cledwyn, made about food irradiation, which I am advised is in some countries recognised as an effective measure to reduce levels of pathogens and spoilage organisms in certain foodstuffs, including poultrymeat. The process, which I understand does not induce radioactivity in the food, is not permitted in the United Kingdom at the present time. The noble Lord asked about the report of the advisory committee which is currently reviewing the safety of irradiated foods for the consumer. Health and Agriculture Ministers expect the report during the summer.

I hope that what I have said will indicate the degree to which the Government have involved themselves in these difficult problems. I very much welcome today's debate, even though it has raised difficult questions and in some cases has put me in the position of having to try to answer them. However, I hope that the debate has provided for your Lordships an assurance that the Government will continue to monitor the situation closely, and would be prepared to take further action if it became clear that that would be useful or necessary.

Lord Rea

My Lords, we have had a most interesting, instructive and, I hope, useful debate this evening. I was pleased to hear from the noble Lord the Minister that there has been some improvement on the poultry side, though I must admit to a certain disappointment over his reply. I have a feeling that the Government are being somewhat complacent in this area when the actual figures for salmonella infections are going up. I do not think that it is quite enough to expect that this debate in this House itself will change matters very much, but I can assure the Minister that we on these Benches will continue to remind the Government of the problem from time to time when figures are presented to us. It only remains for me to thank all noble Lords and the noble Baroness who have contributed to this evening's debate, and I beg leave to withdraw the Motion.

Motion for Papers, by leave, withdrawn.