Tag Archives: Pathogens

Would I lie to you: Reducing risk of disease in dogs (and humans)

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Approximately 35% of households in the United States and Canada own 1 or more dogs, totaling an estimated 75 million dogs in the United States and Canada. Despite continuous development of health promotion and disease prevention products and strategies, infectious disease remains an important contributor to disease and death for dogs. Hundreds of pathogens infectious to dogs have been identified, with more emerging over time.3 Some of these pathogens can also cause disease in people, leading to published recommendations to reduce the risks of human disease associated with animal settings.

sadie-dog-powellMany opportunities for transmission of infectious disease are amplified when dogs are brought together in a shared environment. Settings that involve the temporary congregation of numerous dogs for competition, play, or boarding (often from various geographic locations) are of particular infectious disease concern. Such canine group settings are popular; some of these activities may involve thousands of dogs attending events over several days. Infectious agents introduced into these group settings may lead to disease outbreaks, with the potential for further spread into the communities where the dogs reside, putting many dogs (and potentially humans) at risk.

The process of preventing or reducing the transmission of infectious diseases is complex. Disease agents vary in environmental stability, transmission modes, infectivity (ability to spread between hosts), pathogenicity (ability to cause disease), and virulence (ability to cause severe disease). Additionally, a combination of individual-, population-, and environment-level factors influences the development of infectious diseases in dogs. Individual-level factors include age, immune and health status, acquired immunity (previous infection or vaccination), diet, preventive care (eg, ecto- and endoparasite control), and hand hygiene by the people that handle them. Population- or event-level factors include herd immunity, dog density, event cleaning and disinfection practices, and degree of direct and indirect dog-to-dog contact. Environment-level factors include exposure to infectious agents through pathogen-infected vectors (influenced by geography, time of year, and degree of contact with vector-dense locations) or wildlife or their contaminated environment (eg, urine- or feces-contaminated water).

Some factors have individual- and event-level components requiring an integrated approach to risk management. For instance, to reduce indirect pathogen spread, individual efforts, such as the practice of hand hygiene between handling of dogs and use of effective disinfectants, must complement event-level procedures, such as policies and availability of disinfectant and hand hygiene products.

Given the complexity and importance of integrating individual- and event-level efforts, effective disease prevention in canine group settings would be facilitated by evidence-based guidelines that could be widely disseminated and flexibly applied to create disease prevention, risk mitigation, and control programs. In human group settings, disease prevention programs involving standards, recommendations, and regulations are commonly used; similar programs are also being applied in equine group settings. On the other hand, limited standards, guidelines, recommendations, or regulations currently exist regarding infectious disease prevention for canine group settings. For instance, the American Kennel Club has limited rules for addressing infectious disease opportunities during its dog events, and although policies have been developed for many dog parks and privately owned boarding facilities, no standard set of recommendations exists to guide such policies.

Animal shelters house concentrated populations of dogs and have developed resources to guide disease prevention and control programs in their facilities; however, such settings involve a largely unowned population, necessitating somewhat different strategies. The objectives of the literature review reported here were to identify the specific risks of infectious disease transmission among owned dogs in transient group settings in the United States and Canada and use this information to develop prevention and control recommendations.

Risk reduction and management strategies to prevent transmission of infectious disease among dogs at dog shows, sporting events, and other canine group settings

Journal of the American Veterinary Medical Association

September 15, 2016, Vol. 249, No.6

Stull et al

http://avmajournals.avma.org/doi/full/10.2460/javma.249.6.612

FDA authors publish cost of foodborne illness: totals and per case estimates

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There’s a lot of excitement around societal costs of foodborne illness as a justification for  research dollars, communication resources and measuring any impacts of risk-reduction activities.

In 2010, the Produce Safety Project supported by the Pew Charitable Trusts estimated the US societal cost of foodborne illness at $152 billion annually  A 2012 Journal of Food Protection paper by Robert Scharff estimated, with a couple of different base models, that the annual cost of illness was in between $51 billion to $77 billion. Last fall USDA ERS released updated cost estimates for 15 pathogens.dollar sign

An early release version of a Risk Analysis paper by U.S. FDA risk folks (Minor et al.) estimates the cost of foodborne illnesses (including some that have been omitted by others in previous models) at $36 billion, and the average cost burden per illness of $3,630.

From the methods:

The total cost of a foodborne illness combines mortality costs with the value of lost QALDs and medical costs for acute illnesses and sequelae. Each element in the measure is weighted by its frequency. For each known agent or disease that causes foodborne illness we estimate the full monetary cost of illness based on the expected severity of the acute illness, the expected severity of any sequelae, and the probability of premature death. Each of these estimates is derived from Monte Carlo simulations using the statistical package @Risk and full distributions, where available, as inputs.

The biggest surprise for me was the average annual monetary loss per case of Cronobacter is estimated to be $7,013,777. The authors explain that Cronobacter ‘is estimated to be significantly different from the other foodborne illnesses due to its associated duration and severity; it is also rare.’ There aren’t many cases of Cronobacter sakazakii, but they are almost all associated with infants being fed powdered formula – and they are devastating.

Clostridium botulinum, Vibrio vulnificus, L. monocytogenes, Ciguatoxin, and Trichinella spp. are the next most costly illnesses all representing over 10 QALDs lost per illness, with an associated total monetary loss between  $12,135 and $1.51 million. On the other extreme, B. cereus, Clostridium perfringens, Staphylococcus aureus, Norovirus, Sapovirus, and Scombrotoxin are all estimated to be the least burdensome individual illnesses; each case representing QALD losses of less than 0.29 or less than $381 in monetary losses.

The limitations of the public health cost estimates are that they do not attempt to include the costs to industry (things like management, loss of business, sales, reputation and others). Although norovirus has an estimated average annual monetary loss per case of only $363, an outbreak, like the one affecting Tycoons in Duluth is likely costing the business, including gift certificates, a lot more than that.

Pathogens in produce, Netherlands edition

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The Dutch have decided to estimate pathogens in their produce in two Journal of Food Protection papers.

Prevalence and concentration of bacterial pathogens in raw produce and minimally processed packaged salads produced in and for the Netherlands

Journal of Food Protection®, Number 3, March 2014, pp. 352-521 , pp. 388-394(7)

Wijnands, Lucas M.; Delfgou-van Asch, Ellen H. M.; Beerepoot-Mensink, Marieke E.; van der Meij-Florijn, Alice; Fitz-James, Ife; van Leusden, Frans M.; Pielaat, Andannemarie

http://www.ingentaconnect.com/content/iafp/jfp/2014/00000077/00000003/art00006

Recent outbreaks with vegetable or fruits as vehicles have raised interest in the characterization of the public health risk due to microbial contamination of these commodities. Because qualitative and quantitative data regarding prevalence and concentration of various microbes are lacking, we conducted a survey to estimate the prevalence and contamination level of raw produce and the resulting minimally processed packaged salads as sold in The Netherlands. A dedicated sampling plan accounted for the amount of processed produce in relation to the amount of products, laboratory lettuce.skull.e.coli.O145capacity, and seasonal influences. Over 1,800 samples of produce and over 1,900 samples of ready-to-eat mixed salads were investigated for Salmonella enterica serovars, Campylobacter spp., Escherichia coli O157, and Listeria monocytogenes. The overall prevalence in raw produce varied between 0.11% for E. coli O157 and L. monocytogenes and 0.38% for Salmonella. Prevalence point estimates for specific produce/pathogen combinations ranged for Salmonella from 0.53% in iceberg lettuce to 5.1% in cucumber. For Campylobacter, this ranged from 0.83% in endive to 2.7% in oak tree lettuce. These data will be used to determine the public health risk posed by the consumption of ready-to-eat mixed salads in The Netherlands.

Microbiological risk from minimally processed packaged salads in the Dutch food chain

1.Mar.14

Journal of Food Protection®, Number 3, March 2014, pp. 352-521 , pp. 395-403(9)

Pielaat, Annemarie; van Leusden, Frans M.; Wijnands, Lucas M

http://www.ingentaconnect.com/content/iafp/jfp/2014/00000077/00000003/art00007

The objective of this study was to evaluate the microbial hazard associated with the consumption of mixed salads produced under standard conditions. The presence of Salmonella, Campylobacter spp., and Escherichia coli O157 in the Dutch production chain of mixed salads was determined. Microbial prevalence and concentration data from a microbiological surveillance study were used as inputs for the quantitative microbial risk assessment. Chain logistics, production figures, and consumption patterns were combined with the survey data for the risk assessment chain approach. The results of the sample analysis were used to track events from contamination through human illness. Wide 95% confidence intervals around the mean were found for estimated annual numbers of illnesses resulting from the consumption of mixed salads contaminated with Salmonella Typhimurium DT104 (0 to 10,300 cases), Campylobacter spp. (0 to 92,000 cases), or E. coli (0 to 800 cases). The main sources of uncertainty are the lack of decontamination data (i.e., produce washing during processing) and an appropriate dose-response relationship.

Raw kale tale

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Ashley Chaifetz, a PhD student studying public policy at UNC-Chapel Hill writes,

Kale has become the food that apparently does everything: cancer protection, lower cholesterol, provides antioxidant vitamins A, C, and K and minerals iron and potassium, and in the improvement of eye health. Repeatedly called a “superfood” (a quick Google search will reveal over a million hits), kale is often consumed cooked, much like collard, mustard, and turnip greens.IMG_4961

Yet, I’ve been regularly seeing it served raw—in restaurant dishes, recipes in cooking magazines, in friends’ homes, and even in bagged salads at the grocery store.  While it is delicious, I think a lot about how it was grown, processed, and packaged. Microbial food safety might not be number one for kale producers as they might reason that consumers and restaurants traditionally cook the greens and reducing pathogen risk in the process. The control point, historically was in the kitchen.

A couple of years ago, I’d think that raw kale was an anomaly, but given it’s popularity (see: 50 Shades of Kale cookbook, the fact that kale has had a 400% increase in menu appearances over the last 4 years, and even celebrities love it), it seems poised to stick around.

Now that there’s been such a shift to raw consumption, I trust that the industry has addressed the production, harvesting and packing related risks. As a shopper and eater, trust is about all I have since no one is talking about whether growers have taken the appropriate precautions so that it won’t make me sick.

Hand dryers might be better for the environment; worse for limiting disease spread

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I like to write at Starbucks. There’s something about the background activity and lattes, mixed with Neil Young on my iPod, that helps me focus. I hit up a somewhat new outlet in Raleigh today and needed a restroom break. After washing my hands I looked around the bathroom for paper towels and all I could find was an air dryer (right, exactly as shown). I wanted paper towels, because using them matters; drying friction helps remove pathogens.

I don’t like blow dryers because the literature shows they accumulate microorganisms from toilet aerosols, and can cause contamination of hands as they are dried by the dryer (Coates et al., 1987; Knights, et al., 1993; Redway,et al., 1994). In 2010, Anna Snelling and colleagues at the University of Bradford (UK) also showed that drying with a blow dryer can recontaminate hands and rubbing with paper towel was the most effective method to reduce pathogens.

Handwashing and food service food safety guru Pete Snyder at the St. Paul-based Hospitality Institute of Technology and Management summarized key aspects of handwashing and drying . Pete says that after hands are washed and rinsed, they must be thoroughly dried and cites data that shows 1-2 log reduction of pathogens from drying. Water and soap loosen the attachment of pathogen to hands. A rinse step dilutes what has been loosened but drying (and the friction associated) is the next step that matters – and the bugs have to go somewhere; I’d rather that be a paper towel instead of being blown all over my pants.

Pete also notes that it is also apparent that many individuals do not dry their hands thoroughly when using a blow dryer; hence, moisture, which is conducive to microbial growth, remains on hands, or people dry their hands on their clothing.

Starbucks, proper handwashing requires guest access to the proper tools – and that means vigorously running water, soap and paper towel.

Coates, D., D. N. Hutchinson, and F. J. Bolton. 1987. Survival of thermophilic campylobacter on fingertips and their elimination by washing and disinfection. Epidem. Inf. 99:265-274.

Knights, B., C. Evans, S. Barrass, and B. McHardy. 1993. Hand drying – A survey of efficiency and hygiene. The Applied Ecology Research Group, University of Westminster. London, UK.

Redway, K., B. Knights, Z. Bozoky, A. Theobald, and S.Hardcastle. 1994. Hand drying: A study of bacterial types associated with different hand drying methods and with hot air dryers. Applied Ecology Research Group, University of Westminster. London, UK. 14. Brodie, J. 1965. Hand hygiene. Scot. Med. J. 10:1:115-125.
 

Iguana for you? The biological risks of eating reptiles

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A study published last year in the International Journal of Food Microbiology shows that people can catch certain diseases (trichinosis, pentastomiasis, gnathostomiasis and sparganosis) by eating the meat of reptiles such as crocodiles, turtles, lizards or snakes (or iguanas, right).

Simone Magnino, lead author of the study and a researcher for the World Health Organization (WHO), told the Spanish Foundation for Science and Technology that,

"The clearest microbiological risk comes from the possible presence of pathogenic bacteria, especially Salmonella, and also Shigella, Escherichia coli, Yersinia enterolitica, Campylobacter, Clostridium and Staphylococcus aureus, which can cause illnesses of varying degrees of severity."

This expert says the data about risks to public health are still inconclusive, since there is no comparative information about consuming this meat and the prevalence of pathogens. Also, there are few published research articles about cases of illness associated with consuming reptile meat.

The experts advise people to freeze the meat, just as they would with other foods from animal sources, since this deactivates parasites. Industrial processing and proper cooking (not leaving the meat raw) can also kill off pathogens.

Citation: Simone Magnino, Pierre Colin, Eduardo Dei-Cas, Mogens Madsen, Jim McLauchlin, Karsten Nöckler, Miguel Prieto Maradona, Eirini Tsigarida, Emmanuel Vanopdenbosch and Carlos Van Peteghem. "Biological risks associated with consumption of reptile products." International Journal of Food Microbiology 134 (2009) 163, September 2009.
 

New Zealand fruit and vegetable safety – good, but we’ll make sure we do better

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Every time there is a food safety outbreak with fresh fruits and vegetables, some journalist or lobby group will call up and say something like, “we want to do some sampling for E. coli or Salmonella and fresh produce.”

And every time, Chapman or I will walk the person through the limitations with testing, especially in fresh produce.

New studies by the New Zealand Food Safety Authority (NZFSA) highlight the limitations. In one, two out of 900 samples tested positive for Salmonella in lettuce, both from lettuces from the same grower.

In a related study, none of the chemical residues detected were of health concern, although NZFSA principal advisor for chemicals Dr Paul Dansted says he is disappointed with results from this year’s Food Residue Surveillance Programme (FRSP), which targets food likely to show up problems. This year’s focus was on spinach, celery, ginger and garlic.

“A significant number of samples had levels over the maximum residue limit (MRL) which is used for monitoring purposes, but it’s important to stress that dietary intake assessments on the non-compliant food showed none posed a health or food safety concern.”

Eight out of 27 celery samples and four out of 24 spinach samples had residues that were over the limit. There were none over the limit in 50 samples of garlic, but ginger had 11 samples out of 39 over the limit.

“Celery and spinach can be more vulnerable to persistence of chemical residues,” Dr Dansted says. “Because of their shape, residues that wash off in the rain can collect in the base of the plant. We expected to find some problems, but this is not good enough. We will take regulatory action to ensure better compliance in future.”

Properly structured sampling programs are essential to validate that food safety programs are working. But testing is not enough.
 

UK petting zoo E. coli O157 outbreak: 36 confirmed sick; 12 in hospital all under age of 10; four in serious condition; this won’t turn out well

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It’s like people in the U.K. had never heard of E. coli O157. Despite outbreak after outbreak – often involving children at nurseries — public inquiries and a single food safety agency, the Brits just seem oblivious when it comes to dangerous pathogens that send kids to the hospital.

This morning, the London Times reported that

“Thousands of children across the South of England may be at risk from the E. coli bug in what looks to be the largest UK outbreak linked to transmission from farm animals."

Godstone Farm in Surrey, a popular family attraction where children are encouraged to stroke and touch animals, is closed while the Health Protection Agency (HPA) conducts tests to find out the cause of the outbreak which has left 12 children in hospital, four of them in a serious condition.

About 1,000 children, mainly from South London, Surrey, Kent and Sussex, visit the farm every day during the school holidays and at weekends. It is feared that 30,000 children could be at risk of infection.

It has emerged health officials knew about the outbreak among people who visited the farm days before it was closed to the public.

The Health Protection Agency became aware of the outbreak in late August after cases were traced to the farm.

One parent has expressed her anger, saying the decision for the farm to remain open was an "absolute disgrace".

But farm manager Richard Oatway said the farm had acted responsibly and was co-operating with the investigation.

Richard, please share with us your knowledge of natural reservoirs of E. coli O157, and the steps you’ve taken to control such dangerous pathogens from infecting children who visit your farm. Handwashing isn’t enough.
 

Fit, food and fresh produce

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Food is 21st century snake oil. In an era of unprecedented affluence, consumers now choose among a cacophony of low fat, enhanced nutrient staples reflecting a range of political statements and perceived lifestyle preferences, far beyond dolphin free tuna.

On May 17, 2001, Procter & Gamble announced that it was discontinuing its Fit Fruit & Vegetable Wash in the United States, Canada and Mexico effective September 28, 2001. The company said the market was too small for continued investment.

But FIT is still out there. And someone e-mailed me about it the other day.

I’m not up on the current version of Fit being marketed, but in fall 2000, I contacted P&G to ask for the data substantiating the claim that Fit would eliminate 99.9 per cent of bacteria on fresh produce,

After a bunch of calls to various PR types I got hooked up with some scientists at P&G in Cincinnati, who verbally told me that sample cucumbers, tomatoes and the like were grown on the same farm in California, sprayed with chemicals that would be used in conventional production, and then harvested immediately and washed with Fit or water. The Fit removed 99.9 per cent more, or so the company claimed, because no data was ever forthcoming.

One problem. Many of the chemicals used have harvest after dates, such as the one tomato chemical that must be applied at least 20 days before harvest. Residue data on produce in Canadian stores reveals extremely low levels, in the parts per million or billion. So that 99.9% reduction is really buying consumers an extra couple of zeros in the residue quantity, all well below health limits.

No idea what the new Fit is promoting. But pathogens and chemicals in fresh produce need to be controlled on the farm, and in transportation and distribution. 
 

Top 10 reasons telling people to ‘just cook it’ sucks as a food safety strategy

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About 18 months after the 1993 Jack-in-the-Box E. coli O157:H7 outbreak, I, the erstwhile graduate student, gave a talk to a bunch of food safety types from government and industry. I showed a clip from ABC’s 20/20 television program about a family fighting for regulatory change, and many in the audience laughed at the family when their kitchen was shown. Audience members commented that the consumers were sloppy in their cooking and of course they got sick, and if only they would cook hamburger properly E. coli O157:H7 wouldn’t happen.

I thought the response of the audience was sort of appalling.

In mid-1994, Michael Taylor was appointed chief of USDA’s Food Safety and Inspection Service.  On Sept. 29, 1994, USDA said it would now regard E. coli O157:H7 in raw ground beef as an “adulterant,” a substance that should not be present in the product. By mid-October, 1994, Taylor announced plans to launch a nationwide sampling of ground beef to assess how much E. coli O157:H7 was in the marketplace. The 5,000 samples would be taken during the year from supermarkets and meat processing plants “to set an example and stimulate companies to put in preventive measures.” Positive samples would prompt product recalls of the entire affected lot, effectively removing it from any possibility of sale.

That’s the long-winded version for what a USDA official said in a 1994 television interview: we’ll stop blaming consumers  when they get sick from the food and water they consume.

But the just-cook-it crowd persisted. And still does today.

A couple of weeks ago, while announcing a ground beef recall in Colorado, the U.S. Department of Agriculture’s Food Safety Inspection Service stated in a release,

FSIS would like to remind consumers of the importance of following food safety guidelines when handling and preparing raw meat. Ground beef should be cooked to a safe minimum internal temperature of 160° Fahrenheit.

I would like to remind FSIS that it ain’t so easy to handle contaminated ground beef and not spread it around a home or food service kitchen.

Jim Marsden, a former vp at the American Meat Institute and now a professor at Kansas State University, wrote in his meatingplace.com blog last week, the top-10 reasons “just cook it” does not, and will not, work.

1. E. coli O157:H7 is a unique pathogen. The levels of this organism necessary to cause infection are very low.

2. The severity of the disease E. coli O157:H7 can cause, especially in children is devastating.

3. In many cases, parents order hamburgers for their children and rely on restaurants to cook them properly.  In restaurants, parents really have no control over whether the hamburgers they order are sufficiently cooked to eliminate possible contamination from E. coli O157:H7.

4. If consumers unknowingly bring this pathogen into their kitchens, it is almost impossible to avoid cross contamination. Even the smallest amount of contamination on a food that is not cooked can cause illness. Many of the reported cases of E. coli O157:H7 have involved ground beef that was clearly cooked at times and temperatures sufficient to inactivate E. coli O157:H7.  Some other vector, i.e. cross contamination was probably involved.

5. Even if consumers attempt to use thermometers to measure cooking temperature, it is difficult to properly measure the internal temperature of hamburger patties. They would have to use an accurate thermometer and place the probe exactly into the center of the patty. In addition, the inactivation of E. coli O157:H7 is dependent on cooking time and temperature. For example, if they cook to 155 degrees F, they should hold that temperature for 16 seconds. It is not realistic to expect that consumers, many of which are children will scientifically measure the internal temperature of hamburgers.

6. The way ground beef is packaged, it is virtually impossible to remove it from packages or chubs and make patties without spreading contamination if it is present.

7. Sometimes ground beef appears to be cooked when it really isn’t. There is a phenomenon called “premature browning” that can make ground beef appear to be fully cooked when in fact it is undercooked.

8. E. coli O157:H7 may be present in beef products other than ground beef. For example, in non-intact beef products, including tenderized steaks that are not always cooked to temperatures required for inactivation.

9. There have been many cases and outbreaks of E. coli O157:H7 associated with foods that are not cooked (i.e. fresh cut produce).

10. As Senator Patrick Leahy said after the 1993 Jack-in-the-Box outbreak – “The death penalty is too strong a punishment for undercooking a hamburger”.  He was right –consumers will make mistakes. There needs to be a margin of safety so that undercooking does not result in disease or death.