A Made-in-Canada Solution to E. coli O157 Outbreaks

B. Brett Finlay — Fri, 02 Nov 2012 05:05:09 +0000

The recent largest beef recall in Canadian history and its resulting economic and health consequences illustrates the complexities and difficulties associated with Canadian beef safety. However, there is currently a simple, unused, practical and economically viable solution to avoiding such beef recalls as well as preventing E. coli O157 outbreaks — we should vaccinate cattle against E. coli O157:H7. Research shows this Canadian-discovered and commercialized vaccine would significantly decrease O157 in cattle and reduce the subsequent human health problems. E. coli is a bacterium that is found in the intestines of all people, and is the best-studied free living organism, being used for recombinant DNA work, biotechnology, and many other uses. However, there are certain strains of E. coli that have acquired additional DNA that encode the ability to cause human disease, including meningitis, urinary tract infections or diarrhea, and in the case of O157, severe diarrhea which can progress to a fatal kidney disease called hemolytic uremic syndrome, and long-term consequences including brain damage and chronic kidney failure. Several years ago, our laboratory at UBC discovered how O157 adheres to intestinal cells. With this knowledge, we considered the unorthodox concept of vaccinating cattle to prevent human disease. Approximately half of all cattle carry O157 in their intestines, although it causes no disease in cattle. Virtually all human disease come from cattle carrying O157, either through direct contamination of processed meat, (current recall) or by using irrigation water that contains cattle fecal contamination (eg. spinach recall) or as a drinking water supply, as in the Walkerton outbreak. We know that decreasing O157 in cattle would decrease human disease. In collaboration with the University of Saskatchewan, we did experimental trials in which we vaccinated cattle which proved very effective in blocking O157 shedding. Bioniche Life Sciences Inc. is an Ontario company that licensed the technology and did vaccine studies in thousands of cattle to show vaccine efficacy. The vaccine worked extremely well, showing there is a 99-per-cent reduction in bacteria shed in the feces and a 71-per-cent reduction in the proportion of animals shedding. It even caused decreased O157 levels in unvaccinated cattle when they were in pens with vaccinated animals. The vaccine, called Econiche, was commercially approved for use in Canada in 2008. Unfortunately, for a variety of reasons the vaccine has not been used. The vaccine costs $3 per dose, and it requires two doses per animal. Farmers have no incentive to ask their vet to vaccinate their cattle, as it doesn’t cause disease in cattle. They also have no financial incentive to spend this additional amount on the vaccine, as there is no current way to recoup this expense. There have been several independent scientific studies showing that if a vaccine was used, it would be very effective in vastly decreasing, if not eliminating O157 from processed beef. Moreover, the cost to vaccinate all 12.5 million cattle in Canada would be approximately $50 million, yet the current yearly cost for health care related expenses due to human O157 illness is over $200 million — not counting deaths. This does not include the large commercial expenses associated with beef recalls, food inspections and the negative international press associated with O157 recalls and outbreaks. This vaccine is the first in the world and represents a major opportunity to block O157 at the “preharvest” stage. Nearly all current control measures now used occur during processing or during inspections and sampling post-harvest. All data show the vaccine is a highly effective measure, yet it is not being used. To implement the vaccine, it will take both agricultural and health ministries in provincial and federal governments to participate, as well as a concerted effort by farmers and beef processors to implement the vaccine. Some of the cost could even be passed along to consumers to ensure safer beef products. All studies show the vaccine is completely safe, both for cattle and humans, extremely effective and makes strong economic and business sense, saving governments at least $150 million per year. There will always be O157 in beef until the vaccine is adopted and no amount of inspectors will detect all O157. The time is now to implement this unique made-in-Canada solution to avoid future recalls, outbreaks, human disease and death, and give Canadian beef a much improved image worldwide.

B. Brett Finlay | Food Safety News

A Made-in-Canada Solution to E. coli O157 Outbreaks