Friday, March 28, 2008
Monday, March 10, 2008
What does it take to make us clean up our act?
Having lived in Hong Kong for a while, I am perhaps more aware of the potential for the spread of diseases than the average Kiwi. The Chinese have suffered SARS and bird flu and are very keen to avoid more outbreaks of either. If you sneeze in public, people will stare accusingly at you; people who have a cold will voluntarily wear a face mask out of consideration for others; there are hand sanitizing stations around public buildings and patrons are warned not to feed birds in outdoor eating areas.
With these thoughts in mind, I have been surprised to see the couldn’t care less attitude of some businesses here at home. When a fly crawling over the goods in a bakery was pointed out to the assistant, she shrugged her shoulders and said that it was impossible to keep them out. There is a coffee and cake shop on the podium level of the apartment block where I live. They have a resident population of flies there too. But in addition, they have birds. Not in cages as decoration, but possibly as employees. These birds hop around on the floor and pick up crumbs. They also hop onto the tables on the terrace and finish off the meals left by the patrons – the plates stay on the tables long after the diners have left. This is just not acceptable in any food service premises.
New Zealand has been lucky and so far avoided bird flu scares. However, bird flu is not the only concern. When birds hop around on floors or tables and perch on chairs, they are inclined to leave droppings behind. If eventually an assistant comes to remove the plates, the table will be wiped with a cloth, spreading a thin film of droppings around and probably contaminating the whole surface with faecal bacteria and viruses. Of course, we don’t eat off the table, but it would be hard not to touch it and so there is a risk of ingesting these organisms, particularly if we eat cakes or breads with our fingers.
I would have expected these failings to be brought to the attention of the shop owners by the authorities. Perhaps we also put too much faith in antibacterial sprays. Are they an extension of the plastic glove = bullet-proof syndrome? We need to see safety in practice, not just in a manual on the manager’s shelf. I hope it will not take a SARS epidemic or outbreak of bird flu to convince these businesses to clean up their act.
With these thoughts in mind, I have been surprised to see the couldn’t care less attitude of some businesses here at home. When a fly crawling over the goods in a bakery was pointed out to the assistant, she shrugged her shoulders and said that it was impossible to keep them out. There is a coffee and cake shop on the podium level of the apartment block where I live. They have a resident population of flies there too. But in addition, they have birds. Not in cages as decoration, but possibly as employees. These birds hop around on the floor and pick up crumbs. They also hop onto the tables on the terrace and finish off the meals left by the patrons – the plates stay on the tables long after the diners have left. This is just not acceptable in any food service premises.
New Zealand has been lucky and so far avoided bird flu scares. However, bird flu is not the only concern. When birds hop around on floors or tables and perch on chairs, they are inclined to leave droppings behind. If eventually an assistant comes to remove the plates, the table will be wiped with a cloth, spreading a thin film of droppings around and probably contaminating the whole surface with faecal bacteria and viruses. Of course, we don’t eat off the table, but it would be hard not to touch it and so there is a risk of ingesting these organisms, particularly if we eat cakes or breads with our fingers.
I would have expected these failings to be brought to the attention of the shop owners by the authorities. Perhaps we also put too much faith in antibacterial sprays. Are they an extension of the plastic glove = bullet-proof syndrome? We need to see safety in practice, not just in a manual on the manager’s shelf. I hope it will not take a SARS epidemic or outbreak of bird flu to convince these businesses to clean up their act.
Sunday, February 10, 2008
Campylobacter jejuni - SEM image
Scanning electron microscope image of Campylobacter jejuni, illustrating its corkscrew appearance and bipolar flagella. Source: Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, Virginia.
Saturday, February 9, 2008
That Campylobacter problem – it just doesn’t go away
It has been fascinating to watch the news reports, both here in New Zealand and overseas, over the last few weeks and see the different takes. The New Zealand Food Safety Authority announced on 15th January the introduction of a Code of Practice for the poultry industry. The code is intended to reduce the incidence of campylobacteriosis in New Zealand, which is the highest in the developed world. The code has received mixed reviews and the language used has at times been intemperate. The blame for much of this disease has been laid at the door of the poultry industry as suppliers of “New Zealand’s cheap and dirty food”. In a Radio NZ interview, Dr. Mike Baker claimed that when chicken is prepared in a kitchen, every surface in the kitchen will be covered with bacteria and the aprons of workers in restaurant kitchens will potentially be covered in a layer of Campylobacter.
When interviewed by the Taranaki Daily News, a Tegel spokesman said that the Company fully supported the new code. Sharon Wagener of NZFSA says that the code formalises a lot of what was already happening voluntarily in the industry. However, on the Green Party website their spokesman Sue Kedgley claimed that the code “fails to include some very simple measures to stem the tide of Campylobacter contamination of chicken meat being sold to New Zealanders”. Some of the points raised by Ms. Kedgley in relation to problems of mechanical handling and leaky packaging are not in dispute, but are already being addressed by the industry.
The Taranaki Medical Officer of Health, Richard Hoskins, noted that the Health Board has had interactions with Tegel (which of course is not the only chicken processor in the country) in efforts to reduce the incidence of the disease. He apparently expressed the view that the Board was "pretty impressed with the efforts they are going to".
Michael Brooks, the Executive Director of the Poultry Industry Association of New Zealand, has also stated that based on figures collected by ESR, human campylobacteriosis case rates have been steadily declining since August 2006, in some months showing a drop of 30-35% over the corresponding previous year. Of course, this does not satisfy everyone; the incidence of campylobacteriosis tends to be somewhat variable from month to month and it will require proper statistical analysis over some years to demonstrate a true decrease.
The adversarial approach being taken by some of the interested parties is not, in my view, the best way forward. Nobody has the complete right answer; where has the still small voice of reason and collaboration gone? Wouldn’t it be better if the parties worked together, using scientifically demonstrable facts and not overheated opinion to put together the jigsaw puzzle and solve the problem?
The fact is that human infection by Campylobacter is a very complex problem and simply pointing the finger at the poultry industry will not solve it, no matter what codes of practice are imposed. Take just one point: sub-typing of Campylobacter, using molecular methods, can show the relatedness of various isolates from poultry and from humans. In some parts of the country, a single sub-type is found in up to 20% of human cases and in poultry. In other parts, the sub-typing shows that human cases do not share the same types as found in poultry. Nobody is claiming that poultry does not contribute significantly to campylobacteriosis in New Zealand, but the industry takes this seriously and is doing something about it, having issued its own Broiler Growing Biosecurity Manual in consultation with NZFSA in August 2007. This describes the minimum standards to be used in NZ broiler production systems, aiming at ensuring the products meet food safety and suitability requirements and consumer needs. Campylobacter is a commensal bacterium – it is found in poultry and some other animals and does not cause them to be ill, so getting rid of it is going to require considerable effort and some cost on the part of farmers and processors.
The code comes into force on the first of March 2008.
For more information on Campylobacter, click here
When interviewed by the Taranaki Daily News, a Tegel spokesman said that the Company fully supported the new code. Sharon Wagener of NZFSA says that the code formalises a lot of what was already happening voluntarily in the industry. However, on the Green Party website their spokesman Sue Kedgley claimed that the code “fails to include some very simple measures to stem the tide of Campylobacter contamination of chicken meat being sold to New Zealanders”. Some of the points raised by Ms. Kedgley in relation to problems of mechanical handling and leaky packaging are not in dispute, but are already being addressed by the industry.
The Taranaki Medical Officer of Health, Richard Hoskins, noted that the Health Board has had interactions with Tegel (which of course is not the only chicken processor in the country) in efforts to reduce the incidence of the disease. He apparently expressed the view that the Board was "pretty impressed with the efforts they
Michael Brooks, the Executive Director of the Poultry Industry Association of New Zealand, has also stated that based on figures collected by ESR, human campylobacteriosis case rates have been steadily declining since August 2006, in some months showing a drop of 30-35% over the corresponding previous year. Of course, this does not satisfy everyone; the incidence of campylobacteriosis tends to be somewhat variable from month to month and it will require proper statistical analysis over some years to demonstrate a true decrease.
The adversarial approach being taken by some of the interested parties is not, in my view, the best way forward. Nobody has the complete right answer; where has the still small voice of reason and collaboration gone? Wouldn’t it be better if the parties worked together, using scientifically demonstrable facts and not overheated opinion to put together the jigsaw puzzle and solve the problem?
The fact is that human infection by Campylobacter is a very complex problem and simply pointing the finger at the poultry industry will not solve it, no matter what codes of practice are imposed. Take just one point: sub-typing of Campylobacter, using molecular methods, can show the relatedness of various isolates from poultry and from humans. In some parts of the country, a single sub-type is found in up to 20% of human cases and in poultry. In other parts, the sub-typing shows that human cases do not share the same types as found in poultry. Nobody is claiming that poultry does not contribute significantly to campylobacteriosis in New Zealand, but the industry takes this seriously and is doing something about it, having issued its own Broiler Growing Biosecurity Manual in consultation with NZFSA in August 2007. This describes the minimum standards to be used in NZ broiler production systems, aiming at ensuring the products meet food safety and suitability requirements and consumer needs. Campylobacter is a commensal bacterium – it is found in poultry and some other animals and does not cause them to be ill, so getting rid of it is going to require considerable effort and some cost on the part of farmers and processors.
The code comes into force on the first of March 2008.
For more information on Campylobacter, click here
Sunday, February 3, 2008
Dangerous probiotics? Probably not
Readers may have been concerned to hear last week of 24 unexplained deaths among patients with acute pancreatitis, who were being administered probiotics in a study conducted at the University Medical Centre in Utrecht. The deaths occurred between 2004 and 2007 and represented 16% of the 296 patients in the trial. Unfortunately, the original reports are in Dutch and it is difficult to glean the full facts, including the percentage of patients in the control group who died.
It appears that the patients all had serious acute pancreatitis – inflammation of the pancreas. This disease may have a number of causes, but alcohol abuse and gallstones account for 80-90% of cases. Scarring of the pancreas during an attack may lead to chronic disease that can become life threatening.
The research concerned the functioning of probiotic bacteria administered to reduce the effects of the pancreatitis. The investigation was conducted in fifteen hospitals under the guidance of UMC Utrecht. If I have interpreted the press reports correctly, an investigation of the deceased showed that no infection resulted from the administration of the probiotics. However, three factors appear to be involved: treatment with probiotics of patients having organ failure; treatment of patients in intensive care; treatment of patients being fed by probe directly into the digestive tract. The researchers have recommended that if a patient satisfies one or more of these criteria, they should not be administered probiotics. A similar trial in Czechia has been stopped.
It had been thought that the administration of probiotic bacteria would raise the patients’ resistance to detrimental bacteria colonizing the gut.
Not surprisingly, the main manufacturers of probiotic cultures have reacted strongly, stating that there is no evidence that feeding of probiotics has a deleterious effect on healthy individuals. They have also claimed that the bacteria in the study are different from those in their own products.
I’m sure we haven’t heard the last of this, but in the meantime I suggest that normal, healthy adults should continue eating their probiotic-containing yoghurt or drinking their daily dose of probiotic cultures. The benefits of probiotic bacteria have been known for many years and countless people have consumed them without apparent ill effects. Extrapolating from patients who were already seriously unwell to normal healthy individuals is ill advised.
This morning my muesli and strawberries tasted just great with the addition of probiotic yoghurt!
It appears that the patients all had serious acute pancreatitis – inflammation of the pancreas. This disease may have a number of causes, but alcohol abuse and gallstones account for 80-90% of cases. Scarring of the pancreas during an attack may lead to chronic disease that can become life threatening.
The research concerned the functioning of probiotic bacteria administered to reduce the effects of the pancreatitis. The investigation was conducted in fifteen hospitals under the guidance of UMC Utrecht. If I have interpreted the press reports correctly, an investigation of the deceased showed that no infection resulted from the administration of the probiotics. However, three factors appear to be involved: treatment with probiotics of patients having organ failure; treatment of patients in intensive care; treatment of patients being fed by probe directly into the digestive tract. The researchers have recommended that if a patient satisfies one or more of these criteria, they should not be administered probiotics. A similar trial in Czechia has been stopped.
It had been thought that the administration of probiotic bacteria would raise the patients’ resistance to detrimental bacteria colonizing the gut.
Not surprisingly, the main manufacturers of probiotic cultures have reacted strongly, stating that there is no evidence that feeding of probiotics has a deleterious effect on healthy individuals. They have also claimed that the bacteria in the study are different from those in their own products.
I’m sure we haven’t heard the last of this, but in the meantime I suggest that normal, healthy adults should continue eating their probiotic-containing yoghurt or drinking their daily dose of probiotic cultures. The benefits of probiotic bacteria have been known for many years and countless people have consumed them without apparent ill effects. Extrapolating from patients who were already seriously unwell to normal healthy individuals is ill advised.
This morning my muesli and strawberries tasted just great with the addition of probiotic yoghurt!
Tuesday, January 22, 2008
Hazardous Home-made Ice Cream
We’ve probably all eaten and enjoyed home-made ice cream at some time in our lives. It can be great fun for kids to help Mum make it during the summer holidays.
During the recent summer holiday (Southern Hemisphere), my neighbour gave me a recipe for making ice cream. It seemed simple enough – just combining eggs and cream, vanilla and sugar and then freezing it, stirring at intervals. “The children just love it”. There was no mention of pasteurization, which made me uncomfortable.
I looked for “Ice cream home made” on Google and found many recipes, some of which used eggs. Some included heating steps, some didn’t. This is worrying.
Eggs can potentially be infected with Salmonella during formation in the hen. External contamination can also occur, which may be transferred to the egg contents when the shell is cracked. The egg industry has procedures in place to minimize these risks and commercial egg pulp is pasteurized. This is a fairly delicate balance between providing sufficient heat to kill pathogenic bacteria and not causing the egg proteins to denature.
If you are going to make ice cream at home this summer, I recommend that you either use a recipe that does not call for eggs, or that you use a process that heats the eggs. A typical recipe can be found at:
http://www.cooks.com/rec/doc/0,1613,150189-248198,00.html
where the following instruction is given: “In heavy 3 quart saucepan with wire whisk, combine sugar, flour and salt. Beat in milk and eggs until well blended. Cook over medium low heat, stirring frequently, until mixture thickens and coats spoon, about 30 to 45 minutes. (Do not boil or mixture will curdle.) Cover surface with plastic wrap; cool completely, about 3 hours”.
The temperature of the egg mix needs to get high enough to kill Salmonella bacteria if they are present. This can be achieved by heating the mix to 80C and holding it for 15 seconds.
During the recent summer holiday (Southern Hemisphere), my neighbour gave me a recipe for making ice cream. It seemed simple enough – just combining eggs and cream, vanilla and sugar and then freezing it, stirring at intervals. “The children just love it”. There was no mention of pasteurization, which made me uncomfortable.
I looked for “Ice cream home made” on Google and found many recipes, some of which used eggs. Some included heating steps, some didn’t. This is worrying.
Eggs can potentially be infected with Salmonella during formation in the hen. External contamination can also occur, which may be transferred to the egg contents when the shell is cracked. The egg industry has procedures in place to minimize these risks and commercial egg pulp is pasteurized. This is a fairly delicate balance between providing sufficient heat to kill pathogenic bacteria and not causing the egg proteins to denature.
If you are going to make ice cream at home this summer, I recommend that you either use a recipe that does not call for eggs, or that you use a process that heats the eggs. A typical recipe can be found at:
http://www.cooks.com/rec/doc/0,1613,150189-248198,00.html
where the following instruction is given: “In heavy 3 quart saucepan with wire whisk, combine sugar, flour and salt. Beat in milk and eggs until well blended. Cook over medium low heat, stirring frequently, until mixture thickens and coats spoon, about 30 to 45 minutes. (Do not boil or mixture will curdle.) Cover surface with plastic wrap; cool completely, about 3 hours”.
The temperature of the egg mix needs to get high enough to kill Salmonella bacteria if they are present. This can be achieved by heating the mix to 80C and holding it for 15 seconds.
Monday, January 14, 2008
Botulism is back
Botulism is back in the news. The US Food and Drug Administration has announced that a canning company in Michigan is recalling certain lots of canned beans. The reason given was that these particular batches of product were not adequately heated during the processing.
As I wrote in “Deadly Poison in the Kitchen” on 5th September last year, the testing of canned foods for Clostridium botulinum is impractical. No sampling plan could detect the very low level of faulty cans that we accept. We are therefore totally reliant on the correct delivery of the thermal process by the manufacturer. Not surprisingly, the regulations covering the processing of Low Acid Canned Foods* are tight and specific.
The cans must be heated in a pressurized vessel called a retort at temperatures greater than 100C (the temperature of boiling water) because the C. botulinum spores are very heat resistant. They can survive for longer than 4 hours in boiling water. Full records must be made of the process, using special controllers and monitoring instruments. The retort operator must sign these records as soon as the cooking process is completed and they must be inspected and signed off by a responsible member of Management within 24 hours.
I don’t know the details of the investigation, other than the information provided in the FDA announcement (http://www.fda.gov/oc/po/firmrecalls/newera01_08.html). However, it does appear that the procedures mentioned above were not followed. The FDA announcement, quoting the company, stated that the recall was made “because a records review identified the possibility that a small number of cans from each lot may not have been adequately cooked”. These cans should not have entered the distribution network until after the processing records had been inspected.
For the benefit of anyone who has concerns about the hazards of handling foods thought to be contaminated with the toxin (botulin) I have quoted the FDA release verbatim below:
“Any food that may be contaminated should be disposed of carefully. Even tiny amounts of toxins ingested, inhaled, or absorbed through the eye or a break in the skin can cause serious illness. Skin contact should be avoided as much as possible, and the hands should be washed immediately after handling the food. Customers who have the product or any foods made with these products should throw them away immediately. Double bag the cans in plastic bags that are tightly closed, then place in a trash receptacle for non-recyclable trash outside of the home. Restaurants and institutions are encouraged to assure that such products are only placed in locked receptacles which are not accessible to the public. Additional instructions for safe disposal can be found at www.cdc.gov/botulism/botulism_faq.htm. Anyone with questions can call FDA at 1-888-SAFEFOOD”.
* A Low Acid Canned Food (LACF) is defined as a food packed in an hermetically sealed container, whose finished equilibrium pH is greater than 4.6 This includes, but is not limited to foods like canned beans, peas, carrots, corn etc. It is not safe to try to make these products at home and industrial production must be conducted in approved premises, using processes approved by thermal processing experts and filed with the authority (in the US this will be either FDA or USDA; in New Zealand it is NZFSA).
As I wrote in “Deadly Poison in the Kitchen” on 5th September last year, the testing of canned foods for Clostridium botulinum is impractical. No sampling plan could detect the very low level of faulty cans that we accept. We are therefore totally reliant on the correct delivery of the thermal process by the manufacturer. Not surprisingly, the regulations covering the processing of Low Acid Canned Foods* are tight and specific.
The cans must be heated in a pressurized vessel called a retort at temperatures greater than 100C (the temperature of boiling water) because the C. botulinum spores are very heat resistant. They can survive for longer than 4 hours in boiling water. Full records must be made of the process, using special controllers and monitoring instruments. The retort operator must sign these records as soon as the cooking process is completed and they must be inspected and signed off by a responsible member of Management within 24 hours.
I don’t know the details of the investigation, other than the information provided in the FDA announcement (http://www.fda.gov/oc/po/firmrecalls/newera01_08.html). However, it does appear that the procedures mentioned above were not followed. The FDA announcement, quoting the company, stated that the recall was made “because a records review identified the possibility that a small number of cans from each lot may not have been adequately cooked”. These cans should not have entered the distribution network until after the processing records had been inspected.
For the benefit of anyone who has concerns about the hazards of handling foods thought to be contaminated with the toxin (botulin) I have quoted the FDA release verbatim below:
“Any food that may be contaminated should be disposed of carefully. Even tiny amounts of toxins ingested, inhaled, or absorbed through the eye or a break in the skin can cause serious illness. Skin contact should be avoided as much as possible, and the hands should be washed immediately after handling the food. Customers who have the product or any foods made with these products should throw them away immediately. Double bag the cans in plastic bags that are tightly closed, then place in a trash receptacle for non-recyclable trash outside of the home. Restaurants and institutions are encouraged to assure that such products are only placed in locked receptacles which are not accessible to the public. Additional instructions for safe disposal can be found at www.cdc.gov/botulism/botulism_faq.htm. Anyone with questions can call FDA at 1-888-SAFEFOOD”.
* A Low Acid Canned Food (LACF) is defined as a food packed in an hermetically sealed container, whose finished equilibrium pH is greater than 4.6 This includes, but is not limited to foods like canned beans, peas, carrots, corn etc. It is not safe to try to make these products at home and industrial production must be conducted in approved premises, using processes approved by thermal processing experts and filed with the authority (in the US this will be either FDA or USDA; in New Zealand it is NZFSA).
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