Global News Updates from 2007
Topics:
Animal/Livestock Health Issues
Avian Influenza
Food– and Waterborne Illness Outbreaks
Food Safety Policy Issues
Food Safety Studies
Poultry workers carry antibiotic-resistant germs
19 Dec 2007
World Poultry Net
It has been revealed in a US study that poultry workers are 32 times more likely to carry antibiotic-resistant E. coli bacteria than non-poultry workers.
Researchers at Johns Hopkins University's Bloomberg School of Public Health reported they found that E. coli bacteria in the US poultry industry are resistant to the commonly used antibiotic gentamicin.
While drug resistant bacteria such as E. coli are common in the industrial broiler chicken environment, the researchers said their study is the first US research to show exposure occurring at a high level among industrial poultry workers.
According to Lance Price, the study's lead author, for over 50 years the use of antimicrobials has been present in the United States. There are estimates indicating well over half of the antimicrobial drugs produced in the US are used in food animal production.
FAO – Avian Influenza, global update
19 Dec 2007
CIDRAP News [edited]
Despite recent spikes in H5N1 avian influenza activity in humans and birds, there have been fewer bird outbreaks in fewer countries this year [2007] than in 2006, according to a preliminary report from the United Nations Food and Agriculture Organization (FAO).
As of 10 Dec 2007, 30 countries had reported H5N1 cases in birds this year [2007], compared with 54 in 2006, the FAO reported. This year, 5 countries have reported their 1st outbreaks: Bangladesh, Benin, Ghana, Saudi Arabia, and Togo. Except for sporadic outbreaks in wild birds, most of the H5N1 cases this year occurred in domestic poultry, such as chickens, turkeys, geese, ducks, and quail.
The H5N1 outbreaks seemed to follow a seasonal pattern, in line with evidence that cooler temperatures are more favorable to influenza viruses. The FAO said outbreak numbers in 2007 were high between January and April, declined until September, and then started rising again in November and December.
Increased awareness and improved disease surveillance have enabled countries such as India, Romania, Malaysia, and Turkey to detect and control the spread of the H5N1 virus, the FAO reported. However, the disease persists in Asia, Africa, and Europe and poses a risk for countries that have controlled outbreaks in the past and those that have not experienced infections yet, the organization stated.
The FAO said Indonesia is still having a large number of H5N1 outbreaks in poultry, which largely reflects a new "participatory disease search" program designed to detect infections in backyard poultry. The program, with support from the FAO, is operating in 162 districts and 9 provinces.
Among other Asian hot spots for the disease, Viet Nam reported H5N1 outbreaks in 22 provinces in May 2007, the FAO reported. It said the disease appears to be endemic in Bangladesh.
China had H5N1 outbreaks in Tibet in March 2007, Hunan province in May 2007, and Guangdong province in September 2007, the agency said. In addition, routine surveillance detected the virus in March and April 2007 in the southern Chinese provinces of Fujian, Guangdong, Hunan, Hubei, Sichuan, and Chongqing, the FAO reported. Also, wild bird deaths were reported in Hong Kong but not in mainland China.
The only Middle Eastern country reporting an H5N1 outbreak so far this year [2007] has been Saudi Arabia, which had its 1st cases in March 2007, followed by several outbreaks near Riyadh in November 2007.
In Africa, 4 countries have reported H5N1 outbreaks in 2007, and the FAO said the virus is considered endemic in Egypt and possibly in Nigeria. "Several countries in West, Central, South, and North Africa are at risk of becoming infected, and early warning, surveillance, and preventive measures should urgently be taken," the organization reported.
Eight European countries have reported H5N1 outbreaks in 2007, the FAO noted.
Bird Flu Expert Calls For Changes In Early-warning System
11 Dec 2007
Sciencedaily.com [edited]
The international science community is not doing enough to track the many avian influenza viruses that might cause the next pandemic, a UC Davis researcher says. Global surveillance is critical for identifying and tracking potential pandemic viruses such as highly pathogenic H5N1. But the current surveillance strategy in wild birds is piecemeal and risks missing important virus sources or subtypes, Walter Boyce writes in a commentary.
Boyce says scientists must take several steps to catch avian influenza viruses before they catch us:
- Go where the H5N1 virus lives: Surveillance has focused too heavily on Europe and North America, where few wild birds are infected. To really understand the role of wild birds in spreading H5N1, more surveillance should be done in places where the virus is endemic, such as China, Southeast Asia and Africa, Boyce says.
- Characterize all of the influenza viruses they collect: Currently, the narrow focus on H5N1 misses other viruses that also pose pandemic risks.
- Share samples and data more promptly: Whether caused by regulatory hurdles or researchers' concerns about intellectual property rights, a reluctance to share hampers health officials' ability to track and respond to potential pandemic viruses. Boyce recommends that the scientific community set a standard of releasing data no more than 45 days after it is generated.
The full commentary is published in Nature 7 Dec 2007:
http://www.nature.com/nature/journal/v450/n7171/full/450791a.html
Europe – Bird Flu Expert Calls For Changes In Early-warning System
11 Dec 2007
Sciencedaily.com [edited]
The avian influenza virus H5N1 could become entrenched in chickens and domestic ducks and geese in parts of Europe, FAO warned today [25 Oct 2007]. The agency stressed that healthy domestic ducks and geese may transmit the virus to chickens and play a more important role in the persistence of the virus in the region than previously thought. H5N1 surveillance in countries with significant domestic duck and geese populations should be urgently increased. FAO's warning followed the detection of H5N1 in diseased young domestic ducks by German scientists.
"It seems that a new chapter in the evolution of avian influenza may be unfolding silently in the heart of Europe," said FAO's Chief Veterinary Officer, Joseph Domenech. "If it turns out to be true that the H5N1 virus can persist in apparently healthy domestic duck and geese populations, then countries need to urgently reinforce their monitoring and surveillance schemes in all regions with significant duck and geese production for the presence of H5N1. Europe should prepare for further waves of avian influenza outbreaks, most probably in an east-west direction, if the virus succeeds in persisting throughout the year in domestic waterfowl. This heightens the need for increased surveillance and monitoring of possible virus circulation in domestic ducks and geese."
The link between domestic ducks and geese and chickens is seen by many experts as one of the major underlying factors in outbreaks of HPAI in disease-entrenched countries. "We are particularly concerned about the Black Sea area, which has a high concentration of chickens, ducks and geese," said FAO senior animal health officer Jan Slingenbergh. "In the Ukraine alone, the number of domestic ducks is estimated at around 20 million birds. In Romania, 4 million domestic ducks and 4 million domestic geese are found in the Danube delta. These figures compare easily with chicken and waterfowl densities in Asia, where the virus continues to circulate among chickens and has found a niche in countries with tens of millions of domestic ducks and geese," Slingenbergh said.
Importantly, the Black Sea area serves as a main wintering area for migratory birds coming from Siberia and moving also to the Mediterranean and other regions. All countries bordering the Black Sea have experienced outbreaks of avian influenza in the past, favored by traditional open poultry systems with poor separation between wild and domestic birds.
The link between the H5N1 virus and domestic ducks and geese has recently been confirmed in Germany. Scientists of the Friedrich-Loeffler-Institut in Riems detected the H5N1 virus in diseased young ducks on a farm at the end of August 2007. Further scrutiny at 2 other farms revealed that, despite the absence of clinical signs and mortality in these ducks, the animals had been in contact with the H5N1 virus, because their immune defence system showed antibodies developed in response to the virus. Intensified monitoring finally confirmed pockets of H5N1 on one of the farms.
Based on its experience in fighting avian influenza around the world over the past 3 years, FAO considers that risk assessment, surveillance and virus search strategies should be reviewed, Domenech said. Countries with significant domestic duck and geese populations in Western and Central Europe as well as the Black Sea region should consider the incident in Germany as a wake-up call and should not limit the virus search to chickens. Good surveillance is already in place in many European countries, and the European Commission issued in 2007 very comprehensive guidelines. But there are countries in which more monitoring is urgently needed, including more focus on ducks and geese, which should be considered as particularly risky populations.
"It could well be that there is more virus circulation in Europe than currently assumed," Slingenbergh said. "We are not saying that the virus is widely spread in European countries; in fact, most of the countries are currently virus-free. But undetected localized virus spots in countries with significant waterfowl may pose a continuous risk."
After Asia and Africa, Europe could become the 3rd continent in which H5N1 could become endemic in some areas, FAO said.
FAO – The community summary report on trends and sources of zoonoses, zoonotic agents, antimicrobial resistance and foodborne outbreaks in the European Union in 2006
20 Dec 2007
European Food Safety Authority
Zoonoses are diseases or infections that are transmissible from animals to humans. The infection can be acquired directly from animals, or through ingestion of contaminated foodstuffs. The gravity of these diseases in humans can vary from mild symptoms to life threatening conditions.
In order to prevent these diseases from occurring, it is important to identify which animals and foodstuffs are the main sources of the infections. For this purpose and to follow the developments in the European Union (EU), information is collected and analysed from all EU Member States in order to help the Community to improve control measures in the food production chain aimed to protect human health.
In 2006, twenty-four Member States submitted information on the occurrence of zoonoses, zoonotic agents, antimicrobial resistance and food-borne outbreaks to the European Commission and the European Food Safety Authority (EFSA). Further information on zoonoses cases in humans was acquired from the European Centre for Disease Prevention and Control (ECDC). The information covered 17 diseases. Assisted by its Zoonoses Collaboration Centre, EFSA and ECDC jointly analysed the information and published the results in this annual Community Summary Report. In addition, six countries that were not EU Member States provided information on zoonoses for the report.
Although a small decrease in the cases was observed in 2006 as compared to 2005, Campylobacteriosis remained the most frequently reported zoonotic disease in humans in EU with 175,561 reported confirmed cases in 2006. Salmonellosis was again the second most commonly recorded zoonosis accounting for 160,649 confirmed human cases. However, the incidence of Salmonellosis has decreased in the EU over the past years, and in the last three years this decrease has been statistically significant.
In foodstuffs, the highest proportion of Campylobacter- positive samples was reported for fresh poultry meat, where on average 35% samples were found positive. Campylobacter was also commonly found from live poultry, pigs and cattle. Of particular concern was the high level of resistance to ciprofloxacin observed in these Campylobacter findings, ranging from 30.6% to 56.7% of the isolates. Ciprofloxacin is an antibiotic commonly used to treat human Campylobacteriosis, and this resistance limits the therapeutic options available and may lead to treatment failure.
Salmonella was most often found in fresh poultry and pig meat where proportions of positive samples on average of 5.6% and 1.0% were detected, respectively. However, the majority of the reported food-borne Salmonella outbreaks were related to eggs while meat was the second most common cause. In animal populations, Salmonella was most frequently detected in poultry flocks. The Salmonella prevalence in flocks of laying hens and their breeding flocks has decreased significantly at EU level, which possibly indicates the success of the control measures taken in the sector. No such trends were observed in flocks of broilers.
The number of listeriosis cases has significantly increased in EU over the 5 past years and in 2006 a total of 1,583 human cases were reported. Listeriosis is an important food- borne zoonosis due to the severity of the disease and high mortality related to it. In 2006, the reported mortality in connection with the food-borne listeriosis outbreaks was 14.2%. The Listeria bacteria were most often reported above the legal safety limit from ready-to- eat (RTE) fishery products, followed by cheeses and other RTE products.
Salmonella was once again the main cause of reported food-borne outbreaks in EU but for the first time, food-borne viruses were the second most frequent cause. The number of viral outbreaks is assumed to be severely underreported in the previous years. The reported incidences of yersiniosis and VTEC infection have decreased in EU, but these diseases still accounted for 8,979 and 4,916 human cases in 2006, respectively. VTEC and Yersinia bacteria were reported mainly from cattle, pigs and products thereof.
The two parasitic zoonoses, trichinellosis and echinococcosis, caused 231 and 458 human cases each in EU Member States. In animals, these parasites were mainly isolated in wildlife.
At EU level, the occurrence of bovine tuberculosis slightly increased and that of bovine and sheep/goat brucellosis decreased in the Member States, which are not free of these diseases, compared to 2005. In humans 1,033 brucellosis cases were reported mainly by the non-free Member States. No cases of rabies were reported in humans in 2006. In animals, the majority of infections are reported in the Baltic and some Eastern European MS. Information on other zoonoses, such as Bovine Spongiform Encephalopathy (BSE), Avian Infulenza and Q fever, is also included in the report.
United Kingdom - Milk bug 'stops our bodies from fighting off Crohn's disease'
11 Dec 2007
The Daily Mail- Sean Poulter
A link between a bug found in some fresh milk and Crohn's disease has, according to this story, been established by breakthrough research.
The discovery could bring demands to change milk production methods - perhaps following the common European practice of Ultra Heat Treatment (UHT).
It could also provide the key to antibiotic treatments for the condition, which affects approximately 150,000 Britons.
Doctors have long claimed that a bug called Mycobacterium paratuberculosis (MAP), which is found in cattle and some milk, causes Crohn's.
But the dairy industry has never accepted the link and researchers had failed to prove a connection.
Now scientists at Liverpool University have identified how MAP weakens the body's defence mechanism and so allows other harmful bugs, specifically E. coli, to thrive.
This E. coli, which is known to be present within Crohn's disease tissue in increased amounts, is believed to cause inflammation and sickness.
The story says that Crohn's leads to chronic intestinal inflammation, pain, bleeding and diarrhea. It is a particularly distressing condition among children.
Professor Jon Rhodes, whose work was published in the journal Gastroenterology, was quoted as saying, "MAP has been found within Crohn's disease tissue but there has been much controversy concerning its role in the disease."
He added that MAP releases a complex molecule which prevents white blood cells from killing E. coli.
Professor John Hermon-Taylor, Britain's leading expert on Crohn's, called for a mass vaccination of cattle against becoming infected with MAP in the first place.
He said ultra heat treatment of milk might kill the infection but it would not be a guarantee.
The Dairy Council, which speaks for milk producers, said a number of studies had failed to show a causal link between MAP in milk and Crohn's.
Its director, Dr Judith Bryans, was quoted as saying, "While the findings of the study are interesting, it is important to stress that not all Crohn's patients have MAP in their intestines. This would suggest that there are additional factors which may cause Crohn's disease. There is no need for anyone to alter their consumption of milk based on current scientific knowledge.
Effect of hand wash agents on controlling the transmission of pathogenic bacteria from hands to food
05 Dec 2007
Journal of Food Protection
Fischler, George E.; Fuls, Janice L.; Dail, Elizabeth W.; Duran, Melani H.; Rodgers, Nancy D.; Waggoner, Andrea L.
Abstract:
The goals of this study were to evaluate the effectiveness of two hand wash regimens in reducing transient bacteria on the skin following a single hand wash and the subsequent transfer of the bacteria to a ready-to-eat food item, freshly cut cantaloupe melon. The number of bacteria recovered from hands and the quantity transferred to the melon were significantly less following the use of an antibacterial soap compared with plain soap. The antimicrobial soap achieved >3-log reductions versus Escherichia coli and 3.31- and 2.83-log reductions versus Shigella flexneri. The plain soap failed to achieve a 2-log reduction against either organism. The bacteria recovered from the melon handled by hands treated with antimicrobial hand soap averaged 2 log. Melon handled following hand washing with plain soap had >3 log bacteria in the experiments. Based on previously published feeding studies, an infection rate in the range of approximately 15 to 25% would be expected after ingesting melon containing 2 log CFU compared with ingesting greater than the 3 log transferred from hands washed with plain soap, which would result in a higher infection attack rate of 50 to 80%. The data thus demonstrate there is a greater potential to reduce the transmission and acquisition of disease through the use of an antimicrobial hand wash than through the use of plain soap.
Scotland - Life-saving test kit can identify food bugs in just 5 hours
12 Nov 2007
The Scotsman - Frank Urquhart and Raymond Hainey
Thousands of lives could be saved by a testing kit being developed by Scottish scientists which detects a host of fatal food-poisoning bugs in as little as five hours.
The device will be capable of dramatically reducing the detection time for foodborne diseases such as E. coli, Campylobacter, listeria and Salmonella from the current six days routinely required.
It has already been successfully tested in the laboratories of the Macaulay Institute in Aberdeen. Backers believe the technology could eventually be harnessed to help detect human pathogens, including the killer MRSA bug.
According to Dr. Bahna, reactions may not be to the food, but to something else in the food. In addition to additives, food may contain seafood-associated toxins, parasites or contaminants. Patients with respiratory allergy to mite may get a systemic anaphylaxis after ingestion of mite-contaminated flour.
"It's important for physicians to think about food allergy as the potential cause of a patient's gastrointestinal or dermatological symptoms," said Amal Assa'ad, M.D., professor of pediatrics at the University of Cincinnati and director of Food Allergy & Eosinophilic Disorders Clinic at Cincinnati Children's Medical Center, Cincinnatti, Ohio.
"The eosinophilic gastrointestinal disorders (EGID) which may affect the esophagus, stomach, colon and rectum are mostly chronic and recurrent disorders that adversely impact quality of life for patients and families. Patients with EGID have a high rate of sensitization to food and environmental allergens, and many of them have a high rate of clinical symptoms with various food ingestions. A subset of patients respond to removal of major food allergens from their diet," Dr. Assa'ad said.
"EGID management often requires multiple specialists including the primary physician, allergy and immunology, gastroenterology, nutrition and psychology," she said.
Food allergy is the single leading cause of anaphylaxis. Anaphylaxis is the most severe form of allergic reactions, affecting multiple organ systems. Symptoms can include chest tightness, wheezing, nausea, vomiting, cramping, hives and swelling of the lips and joints. The most dangerous symptoms are breathing difficulties, throat swelling, chest wheezing, dizziness, low blood pressure, shock and loss of consciousness, all of which can be fatal. Patients with severe reactions should have continued access to self-administered epinephrine injections.
Incidence and toxin production ability of Escherichia coli O157:H7 isolated from cattle trucks
23 Oct 2007
Journal of Food Protection®, Volume 70, Number 10, October 2007 , pp. 2383-2385(3) Alonso, Cuesta E.P.; Gilliland, S.E.; Krehbiel, C.R.
Abstract:
Twelve cattle trucks were analyzed for the presence of Escherichia coli O157:H7. Three of them had been washed prior to arrival, and the others had not. Seventy-five percent of the trailers were positive for the presence of this foodborne pathogen. A total of 54 cultures were isolated and identified as E. coli O157:H7, all from the trucks that had not been cleaned. Most of the cultures (96.4%) produced Shiga-like toxin (verotoxin). No E. coli O157:H7 was detected in cattle trucks that were cleaned before arrival at the cattle pens. The incidence of E. coli O157:H7 in transport trailers increases the potential risk of contamination of cattle and transmission from farms to feedlots and to packing plants. This contamination increases the potential of contamination of meat during harvest and the risk of foodborne illnesses.
United States - Irradiation of high-risk foods: Has its time come?
09 Nov 2007
The Prairie Star
Daryll E. Ray who holds the Blasingame Chair of Excellence in Agricultural Policy, Institute of Agriculture, University of Tennessee, and is the Director of UT's Agricultural Policy Analysis Center (APAC), writes that ground beef recalls this year have reached 29 million pounds in 2007 and there are still two months to go.
The size of companies involved in the recalls due to E. coli O157:H7 have ranged from small local firms with local or regional distribution systems to large firms like Topps Meat Company and Cargill Meat Solutions.
It seems to us that tackling a problem like this requires a combination of private and public policy so that we don't continue to see children put on dialysis machines because of what they ate.
The most immediate thing a consumer can do is to make sure that all of the hamburger that they serve is cooked to a minimum of 160 degrees F and that they observe sanitary precautions in the handling of meat and meat products.
On a recent trip, one of us ordered a hamburger at a major restaurant chain-the cooking instruction was "medium." When the hamburger arrived at the table it was not just pink inside, it was raw. Being polite, we went ahead and ate the burger (ouch — dp)
According to the CDC "If you are served an undercooked hamburger or other ground beef product in a restaurant, send it back for further cooking. You may want to ask for a new bun and a clean plate, too." Given the level of recent recalls, that advice takes on a new level of importance because, like others, we had grown complacent about food-borne illnesses.
We also need to look at the meat inspection procedures that are in place and see if there are areas that need to be tightened up. Both consumers and processors have an interest in making sure that the food processing system operates at the highest level of standards. For consumers it may be a matter of life and death and for companies it can mean added costs for the recall and even bankruptcy.
The problem is that despite all the inspections and food cooking and handling recommendations, E. coli and other food-borne illnesses like listeria and Salmonella continue to be a problem. The one public policy that is currently off-the-table is the irradiation of all ground meat products. At the same time, irradiation of all ground meat products could significantly reduce the level of food-borne illnesses, especially when coupled with the maintenance of stringent sanitation procedures at processing plants and proper meat handling procedures in restaurants and at home.
The Food and Drug Administration has determined that irradiation is safe and effective in decreasing or eliminating harmful bacteria. But many oppose irradiation because of its connection to the nuclear industry and concerns about the potential for irradiation to negatively change the food it is used to treat.
There are also concerns among those that want their food as natural as possible with minimal processing of any kind. And then there is the cost issue.
From a public policy perspective, those considerations need to be weighed against the ongoing level of illnesses and deaths caused by food-borne pathogens that can be significantly reduced by the use of irradiation, especially by firms that process the largest quantities of meat and other high-risk products.
China - High Level International Food Safety Forum, Beijing
02 Nov 2007
World Health Organization
The General Administration of Quality Supervision, Inspection and Quarantine and the Ministry of Health of the People's Republic of China, with cosponsorship from the World Health Organization, will host the High Level International Food Safety Forum in Beijing, 26-27 November 2007. The focus will be on the integrated approach to the prevention of foodborne diseases, the sharing of information and expertise, food safety education and capacity building and the promotion of healthy development of international trade of food and agricultural products. The forum will be attended by senior officials from food safety authorities, international and regional organizations, representatives from the food industry and consumer organizations.
WHO Five Keys to Safer Food adapted to travelers
01 Nov 2007
World Health Organization
A new edition of the Guide on Safe Food For Travellers is available is the six WHO official languages. The WHO Five Keys to Safer Food to prevent foodborne diseases were specifically adapted to travellers and WHO is looking for partners to disseminate this message. Following the example of the Five Keys poster translated into more than 50 languages, WHO strongly encourages the translation, reproduction and dissemination of these recommendations. As an example of collaboration, the Beijing Food Safety agency and WHO are cooperating on the promotion of the Five Keys and the Guide for travellers in connection with the 2008 Beijing Olympic Games. WHO would welcome further collaboration to promote food safety messages in international events, especially from national health authorities and departments for tourism.
WTO food safety database serves as handy reference
22 Oct 2007
Food Production Daily - Ahmed ElAmin
Finding out about the food safety requirements and alerts in other countries just got easier, with the World Trade Organization (WTO) launching a searchable database of member governments' measures.
The tool, which documents food, animal and plant safety measures worldwide, is a resource that can help managers meet new export criteria, or find out if there could be a problem with a particular ingredient sourced from a region.
The SPS Information Management System is available at http://spsims.wto.org.
EU project provides risk assessment of acrylamide in heated food
27 Nov 2007
Cordis News - European Commission
A new research area appeared overnight when the presence of acrylamide in heated food was discovered in 2002. One of the first teams to investigate the finding and its implications was the HEATOX team, funded under the EU's Sixth Framework Programme.
The three-year project began in November 2003, bringing together 24 research teams from 14 countries. Most project partners are universities or research institutes, but national authorities and a European consumer organization are also involved.
When the project began, very little was known about the formation of acrylamide in cooked foods. HEATOX has increased knowledge and understanding of the phenomenon, but their findings do not make for happy reading. The team found toxicological evidence suggesting that acrylamide in food may cause cancer. Their findings also suggest that there are ways to decrease exposure to acrylamide, but not to eliminate it: laboratory experiments succeeded in reducing acrylamide levels in bread and potatoes by adjusting the oil/potato ratio in semi-industrial fryers or minimising long yeast fermentation.
The HEATOX project has also found that acrylamide is not the only genotoxic compound that forms when food is heated. The team has created a database of more than 800 heat-induced compounds, of which 50 are highlighted as potential carcinogens based on their chemical structure. Future research should focus on these compounds.
The presence of acrylamide in home-cooked food is minimal in comparison with industrially or restaurant-prepared foods. The team points out that advising citizens on the risks must be a national responsibility as cooking and eating habits vary considerably between countries. General guidelines would advise avoiding overcooking when baking, frying or toasting carbohydrate-rich foods. Further acrylamide intake can also be achieved by following a diet without excessive fat or calorie intake.
The involvement of so many scientists from different disciplines meant that HEATOX was also able to produce intake calculations, chemical reaction models, exposure assessments, in vivo and in vitro toxicity testing, mitigation proposals to reduce intake, analytical methods for biomarkers and levels and a risk characterisation. More than 40 individual research papers have been published in international scientific journals by HEATOX scientists as a result of the project.
Approaches for reducing Salmonella in pork production
15 Nov 2007
Journal of Food Protection®, Volume 70, Number 11, November 2007, pp. 2676-2694(19) Ojha, Shivani; Kostrzynska, Magdalena
Abstract:
Salmonellosis is an important disease in humans and is associated with contaminated food, including pork products. Salmonella infection is invasive in humans, but it usually remains latent within the swine population, creating reservoirs for carcass contamination. Although abattoirs implement stringent procedures during carcass processing, some raw pork products still have Salmonella contamination. To reduce the presence of Salmonella, a dynamic picture of the pork production chain is needed that includes management practices aimed at health and welfare of swine and practices within swine operations that affect the environment and community health. Swine practices indirectly influence the spread of zoonotic enteric pathogens. Pathogens in food animals can escape detection, and critical control points often are missed. Preharvest growth of swine by enhancement of normal gut flora and targeting intestinal pathogens through nonantibiotic approaches might improve food safety and reduce antibiotic residues. In light of the threat posed by multidrug-resistant pathogens, old dogma is being revisited with optimism for potential utility in promoting pre- and postharvest pork safety. This review includes possible approaches that can be implemented in swine operations and postslaughter during pork processing with simultaneous omission of subtherapeutic antibiotics to control Salmonella. We emphasize the vital roles of the veterinarians, pig producers, industry, food research scientists, and government guidelines for the strategic implementation of approaches to Salmonella control across the pork production and processing chains.
Experts report progress in food allergy prevention and diet restrictions
14 Nov 2007
American College of Allergy, Asthma and Immunology (ACAAI)
Progress has been made in food allergy prevention and management according to investigators presenting the latest research at the Annual Meeting of the American College of Allergy, Asthma and Immunology (ACAAI) in Dallas. Important research findings may impact diet restrictions of food allergic patients. According to Robert A. Wood, M.D., professor of pediatrics and international health director, pediatric allergy and immunology at Johns Hopkins University School of Medicine, research has determined a possible role for allergy prevention strategies. These approaches include maternal food avoidance in pregnancy, breast feeding, maternal food avoidance while breast feeding, use of hypoallergenic formulas, delayed introduction of allergenic foods and probiotics.
"A review of 18 studies demonstrates a significant protective effect of exclusive breastfeeding for at least three months for children with high risk for atopy (genetic tendency to develop allergic diseases) against the development of atopic dermatitis and early childhood asthma-like symptoms," he said.
In addition, Dr. Wood has the following recommendations for children at high risk of allergic diseases:
- Avoidance of peanut and tree nuts in pregnancy and while breast feeding
- Supplement breast feeding with a hypoallergenic formula (extensively or partially hydrolyzed)
- Delay solid foods until age six months
- Delay introduction of milk and egg until age 1 and peanut and tree nuts until age 3
- Early intervention when signs of food allergy appear (secondary prevention).
An estimated 6 percent to 8 percent of young children and 4 percent of adults have food allergy. The most common food allergens in infants and young children are cow's milk, hen's egg, peanut (a legume), tree nuts (walnut, hazelnut, Brazil nut, and pecan), soybeans and wheat. Although sensitivity to most allergens is lost in late childhood, allergy to peanut, tree nut and seafood is likely to continue throughout the patient's life. Only approximately 20 percent of children with peanut allergy lose their sensitivity. The most common foods causing allergy in adults are peanuts, tree nuts, fish, crustaceans, mollusks, fruits and vegetables.
Food Allergy Management
Currently, there is no treatment for food allergies, so allergic individuals must strictly avoid the offending food and its products, and be aware of possible cross-reactivity.
"Allergists-immunologists recognize the need to balance the nutritional impact, cost and likely benefits of diet restrictions," said Dr. Wood. "The most ideal primary prevention tactic may be too difficult for the patient to implement."
In his presentation titled "You Can have Allergy to Food & Eat It Too," Sami Bahna, M.D., Dr.PH., professor of pediatrics and medicine, and chief of allergy and immunology, Louisiana State University, Shreveport, La., discussed the impact research studies have on dietary restrictions.
"You may have allergy to a member of a food family, but not to all members of that family," he said. For example, a study on nine common fish found cross-reactivity and allergenicity were highest among cod, salmon, pollack; and lowest among halibut, flunder, tuna and mackerel. Another study on edible nuts indicates cross-reactivity is strong between walnut, pecan and hazelnut; moderate between cashew, pistachio, Brazil nut and almond; and essentially none between peanut and tree nuts.
"You may be allergic to a particular part of a food, but not to another part," Dr. Bahna said. He discussed a study on five fish species showed that fish dark muscle seems to be less allergenic than white muscle. In a study on raw crustacean, in one patient the urticaria occurred on contact with the shell, but not with the meat. In a study of 60 peanut-allergic subjects, none reacted to refined peanut oil, and 10 percent reacted to crude peanut oil. Some people may have allergy to a food processed in a certain way, but not in another, he said. Manufacturing methods used to reduce allergenicity of proteins include heat treatment, enzymatic hydrolysis, ultra-filtration, high intensity ultrasound, gamma irradiation and combinations of these methods.
"In China, where peanut is commonly fried or boiled, peanut allergy is much less prevalent that in the U.S., where peanut is commonly roasted," he said.
Journal of Food Protection publishes two articles on E. coli O157:H7 vaccine efficacy
13 Nov 2007
Newswire Press Release
Two articles have been published in a peer-reviewed journal, the Journal of Food Protection, both in regards to the efficacy of the Company's E. coli O157:H7 cattle vaccine. The two articles relate to field challenge studies conducted at the University of Nebraska-Lincoln involving close to 900 animals in 2002 and 2003.
The first article, "Efficacy of dose regimen and observation of herd immunity from a vaccine against Escherichia coli O157:H7 for feedlot cattle" (R.E. Peterson, T.J. Klopfenstein, R.A. Moxley, G.E. Erickson, S. Hinkley, D. Rogan, and D.R. Smith), supports the hypothesis that use of the Bioniche vaccine effectively reduces the likelihood of cattle shedding E. coli O157:H7. After a three-dose treatment, vaccinated cattle were significantly less likely (73%) to shed the organism than unvaccinated cattle (P(less than)0.0001). The same study noted that there was no indication of affect on (feed conversion) performance or carcass quality, and that vaccinating amajority of cattle within a pen resulted in a significant protective effect to unvaccinated cattle in the same pen. This effect is called "herd immunity".
The second article, "Effect of a vaccine product containing type III secreted proteins on the probability of Escherichia coli O157:H7 fecal shedding and mucosal colonization in feedlot cattle" (R.E. Peterson, T.J. Klopfenstein, R.A. Moxley, G.E. Erickson, S. Hinkley, G. Bretschneider, E.M. Berberov, D. Rogan, and D. R. Smith), highlights the results of a study that looked at the effect of vaccination on the shedding of E. coli O157:H7 by cattle and their colonization by the organism. Vaccinated cattle were 98.3% less likely to be colonized by E. coli O157:H7 at the terminal rectum (where the bacteria are known to collect and reproduce in large quantities). Specifically, the authors were able to isolate E. coli O157:H7 from only one of 140 vaccinated cattle, versus 38 of 141 non-vaccinates (P(less than)0.0001).
Canada - Prion project to assess risk of game meat consumption
11 Nov 2007
Press Release
An international project with European participation investigating the transmission risk of Chronic Wasting Disease (CWD) on humans will receive EUR3.5 million from the Alberta Prion Research Institute (APRI) in Canada. At European level, the study that will involve testing on primates as well as alternative models will be coordinated by the German Primate Centre (DPZ) in Göttingen. Like BSE or Creutzfeldt-Jakob disease (CJD), CWD is a transmissible spongiform encephalopathy (TSE) that affects deer, elk and moose. It is caused by proteinaceous infectious particles (prions), infectious agents composed only of protein. Up to 15% of game in North America has been already been infected.
Game meat is an important branch of the economy in Canada. Hence, consumers of Canadian game meat products might be at risk of contracting CWD if humans are susceptible.
In the framework of the project entitled 'Comprehensive risk assessment of Chronic Wasting Disease transmission of humans using non-human primates', researchers will first extract the prion and then test its effects on primates when either ingested or transmitted in other ways. 'This research is relevant because there are various infection paths - either by eating infected game or by coming into contact with the infectious agent when slaughtering game,' Dr Michael Schwibbe from DPZ told CORDIS News. Moreover, the disease might spread to other animals that are part of the human food chain such as sheep.
General project coordination will be in the hands of the Lethbridge Laboratory at the University of Calgary, Canada. Further participants include the National Institutes of Health (NIH) in Hamilton, USA, and - in addition to the DPZ - the German Robert Koch Institute, the Technical University of Munich, the neuropathology department of the University Hospital Göttingen and the French Atomic Energy Commission (CEA).
Shell egg handling and preparation practices in food service establishments in Finland
23 Oct 2007
Journal of Food Protection®, Volume 70, Number 10, October 2007, pp. 2266-2272(7) Lievonen, S.; Ranta, J.; Maijala, R.
Abstract:
Foodborne outbreaks are often reported to be acquired at food service establishments. As a part of a quantitative risk assessment on the consumer risk of contracting Salmonella infection via shell eggs, we studied how small, medium, and large restaurants, institutional kitchens, and staff canteens (n = 171) purchase, store, and use shell eggs. In addition, we estimated the fraction of raw and undercooked risky egg dishes among all egg dishes served in food service establishments of different sizes and types. The majority of establishments used shell eggs (78%), purchased eggs once per week (39%), and stored eggs at cool temperatures (82%). The size of the food service establishment had a less significant effect on shell egg preparation and handling practices than the type of the establishment. In particular, restaurants and institutional kitchens differed from each other. Restaurants purchased shell eggs more frequently, were more likely to store them at room temperature, stored shell eggs for a shorter period, and were more likely to prepare undercooked egg dishes than institutional kitchens. It was predicted that 6 to 20% of all different egg dishes prepared in a single randomly chosen food service establishment would be risky egg dishes with a 95% Bayesian credible interval of 0 to 96%, showing uncertainty because of the variability between kitchens and uncertainty in kitchen type-specific parameters. The results indicate that although most Finnish food service establishments had safe egg handling practices, a substantial minority expressed risky behavior. Compared with the egg consumption patterns in private Finnish households, however, practices in food service establishments did not prove to be more prone to risk.
Recovery and transfer of Salmonella typhimurium from four different domestic food contact surfaces
23 Oct 2007
Journal of Food Protection®, Volume 70, Number 10, October 2007 , pp. 2273-2280(8) Moore, Ginny; Blair, Ian S.; McDowell, David A.
Abstract:
Domestic food contact surfaces can play an important role in the transmission of foodborne disease, yet debate continues as to which surface materials pose the greatest risk to consumer health in terms of cross-contamination during food preparation. Salmonella typhimurium was inoculated onto stainless steel, Formica, polypropylene, or wooden surfaces (25 cm2) in the presence or absence of protein (tryptic soy broth supplemented with 5% horse serum) and held at room temperature. The pathogen was recovered from the test surfaces immediately after inoculation (T = 0) and every hour for up to 6 h, by a conventional microbiological sampling technique and by direct transfer onto a model ready-to-eat food (cucumber slices). On all surfaces, pathogen numbers declined during the 6-h holding period, with the most rapid reductions occurring within the first hour. The presence of protein significantly increased (P < 0.05) the number of bacteria recovered from all surface types. However, regardless of application medium or holding time, the number of bacteria recovered from Formica (in all cases) and stainless steel (in most cases) was significantly higher than were the numbers on polypropylene or wood. Similarly, regardless of application medium or holding time, significantly higher bacterial numbers were transferred to the model food from Formica or stainless steel than from polypropylene or wooden surfaces. These differences were greater when the bacteria were applied in a protein-rich medium and the test surfaces held for 1 h or more. The results of this study emphasize that differences, both in recoverability and in the number of bacteria transferred to the model food rather than simply reflecting differences in pathogen survival, may also reflect differences in the ability of the test bacteria to remobilize from the different surface types. However, the results also demonstrate a fundamental problem when choosing food contact surfaces, i.e., that those characteristics that make a surface "easy to clean" may also render it more likely to release contaminating pathogens during common food preparation practices.
France - Ultraviolet Light Helps To Secure Water Supply
18 Oct 2007
Science Daily
A major public health issue and economic problem has been addressed in experiments carried out by researchers from the University Denis Diderot in Paris, and the VEOLIA Research Center in Maisons-Laffitte (France).
Extremely chlorine-resistant parasites, known as Cryptosporidium, which cause a diarrheal disease in humans and can lead to significant mortality in immunodeficient patients, become virtually inactive when exposed to industrial UV reactors.
Human contamination of this waterborne disease, known as cryptosporidiosis, occurs by ingestion of the resistant form of the parasite, either directly through person-to-person and animal-to-person routes or indirectly through environmental vehicles including water, food or soil.
Contamination of water resources for drinking water supplies, as well as inadequate water treatment can be responsible for large cryptosporidiosis outbreaks. Up until now, there has been no efficient curative treatment, making it one of the most common causes of waterborne disease within humans in the United States.
Thanks to collaboration between researchers at the Laboratory of Parasitology of the University Denis Diderot, and the VEOLIA Research Center, the efficacy of UV light was demonstrated in large scale tests with pilot equipment.
The article published in FEMS Immunology & Medical Microbiology, a journal of the Federation of European Microbiological Societies, describes how replicate experiments successfully achieved inactivation rate of >99.998% with both reactors. These results confirm the remarkable efficacy of both polychromatic medium-pressure and monochromatic low-pressure UV lamps in conditions that are close to that of many small- or medium-size water distribution units.
France - How one bacteria colonizes the gut and causes food poisoning
18 Oct 2007
Journal of Clinical Investigation - Juan Xicohtencatl-Cortes, Valério Monteiro-Neto, Maria A. Ledesma, Dianna M. Jordan, Olivera Francetic, James B. Kaper, José Luis Puente, and Jorge A. Girón
Food poisoning caused by the bacteria enterohemorrhagic Eschericia coli (EHEC) O157:H7A results in severe abdominal cramps and bloody diarrhea. In the very young and old it can also cause hemolytic uremic syndrome (HUS) — a disease characterized by anemia and kidney failure. A new study by Jorge Girón and colleagues from the University of Arizona, Tucson, has provided new insight into the mechanisms by which EHEC colonize the intestines, which is essential if strategies to prevent infection by this bacteria are to be developed.
The authors determined that EHEC O157:H7 make a number of proteins that come together to form a structure known as an adhesive type IV pilus, which they termed the hemorrhagic coli pilus (HCP). HCP were shown to enable EHEC O157:H7 to adhere to human intestinal epithelial cells in vitro. Furthermore, individuals with HUS, but not individuals who were healthy, were found to mount an immune response to the HCP component Hcp4, indicating that HCPs are produced by the bacteria during infection with EHEC O157:H7.
New model predicts more virulent microbes
17 Oct 2007
New York University Medical Center
Microbes and humans interact in myriad ways, sharing a long history. Many of the most successful microbes are those that inhabit but do not kill their host. Cheaters lose. Tuberculosis settles into the lungs. Helicobacter pylori, the microbe causing ulcers, burrows into the stomach where it thrives on acids. And Salmonella typhi takes up residence in the gallbladder. All of these organisms can persist in our bodies for decades.
A new mathematical model, devised by a microbiologist renowned for his study of H. pylori and a mathematician, provides the framework for understanding how persistent microbes obtain equilibrium with their human hosts. The multi-scale model, published in the October 18, 2007, issue of the journal Nature, is based on the idea that certain microbes and humans evolved together and along the way established complex strategies that enabled them to co-exist. These strategies are contingent in part on human population size.
The model helps explain the rules that govern the transmission of microbes and how they have operated in human history, says Martin J. Blaser, M.D., the Frederick King Professor and Chair of the Department of Medicine, and Professor of Microbiology at New York University School of Medicine. He and Denise Kirschner of the University of Michigan Medical School, Ann Arbor, are authors of the study. The model uses game theory, developed by Nobel prize-winning mathematician John Nash, the subject of the book and movie A Beautiful Mind, to describe a particular type of equilibrium.
The model can be used to better understand microbial responses to a changing human world, says Dr. Blaser. Based on their formulations, our biological future will probably be filled with some "pretty bad epidemics," says Dr. Blaser. "Our model predicts that as effective population size increases and as immunodeficiency increases due to the spread of HIV infection, and an aging population, there will be more virulent organisms. This is bad news for us."
Through the course of human evolution, Drs. Blaser and Kirschner propose that three classes of persistent microbes have evolved, each employing a different biological strategy to avoid being eliminated quickly by their human hosts. TB, H. pylori, and Salmonella are an example of each class. Any microbe that was "cheating" the system, in other words, tried to expand its territory in the body, wouldn't survive because it would likely kill its host.
According to their theory, small populations select for certain kinds of microbial agents. More than 50,000 years ago, when humans lived as hunter-gatherers in small, isolated groups, the majority of microbes were transmitted within families or were those that would emerge late in life. Microbes that were not lethal were favored because there wasn't a large reservoir of people to infect. Any microbe that killed off its hosts, wouldn't have survived itself. H. pylori evolved during this time.
As population size increased and humans became less isolated, organisms that had perfected ways to hide in the body for decades, such as TB and Salmonella typhi, and then suddenly reactivate or get transmitted, evolved. These organisms could afford to induce more disease early in life because they had mechanisms to sustain themselves in human populations.
As even larger societies developed, more virulent organisms, such as measles, emerged because the population could permit the virus to spread. Our most recent epidemics, including influenza in the early 20th century and AIDS today, involve organisms that can kill millions because these highly virulent organisms have a huge pool of people to infect, and still be transmitted.
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