Canadian and US readers of a ‘certain age’ will remember the NORAD Distant Early Warning Line that was a regular news item during the Cold War. The D.E.W. line consisted of a series of radar emplacements across the Canadian Arctic that were designed to give the military an early warning of incoming nuclear missiles from the Soviet Union.

Fortunately, the most serious threat that the D.E.W. line ever needed to deal with was Santa’s annual entry into North American air space every Christmas Eve.

The original D.E.W. line may be obsolete, but the concept has been borrowed by national and regional health officials in both Canada and the USA. The “threat” is contaminated food. The “radar screen” is composed of consumers.

All too often in recent years, the health and agriculture authorities that are supposed to protect the public from food-borne disease have failed to identify a hazard until most of the damage has been done.

• In 2006/2007, Peter Pan Peanut Butter that was contaminated with Salmonella Tennessee caused 425 documented cases of salmonellosis. The earliest onset date was August 1, 2006. The first consumer warning was issued on February 14, 2007. By then, 288 cases of outbreak-related salmonellosis already had been confirmed.
• In 2009, FDA found that pistachio nuts from Setton Pistachio of Terra Bella Inc. (California) were contaminated with several types of Salmonella. The agency collected this information “over several months” and informed CDC of the problem on March 26, 2009. Setton issued a recall notice on March 30, 2009. Fortunately, there was no measurable outbreak of illness – this time. Nevertheless, FDA apparently sat on these Salmonella-positive results for several months before advising CDC.
• In early December 2009, CDC identified a “multistate cluster” of 14 E. coli O157:H7 illnesses with a single genetic fingerprint. Most of the illness onset dates occurred between mid-October and late November. The onset date of the last reported illness was December 14, 2009 – ten days before National Steak and Poultry recalled the remainder of 248,000 pounds of beef products that, finally, were implicated in the outbreak.
• In 2008, the medical director of the Ontario (Canada) Public Health Laboratories blamed the lack of genetic typing capabilities for the delay in recognizing Canada’s lethal Listeria monocytogenes outbreak. It took three weeks, Low told CBC, for a connection to be made between two suspected listeriosis patients and the contaminated meat that they had eaten.
• On September 4, 2012, the Canadian Food Inspection Agency (CFIA) and the US Food Safety and Inspection Service independently found E. coli O157:H7 in raw beef trimmings from XL Foods Inc. No public recall was announced until September 16th – nearly two weeks after the initial E. coli O157:H7-positive test results. On October 1st, the Public Health Agency of Canada (PHAC) finally notified Canadians that it had detected an outbreak of E. coli O157:H7. The onset date of the first confirmed case was September 9th; the 17th – and last – outbreak patient fell ill on October 15th.

On December 5, 2012, PHAC advised CFIA that it had identified a cluster of E. coli O157:H7 illnesses that might be linked to frozen burgers produced by Cardinal Meat Specialists Limited (Establishment 752). The onset date of the first illness was September 30th; that latest was November 22nd. It was only on December 7th that CFIA retrieved samples from the home of one of the five outbreak victims; collection of retail samples for testing began on December 8th. The first Health Hazard Alert/Recall Notice was issued on December 12th, after two retail samples were found to be contaminated. PHAC released its Public Health Notice to advise Canadians of the outbreak on December 17th.

CFIA is now investigating the ingredients used to produce the contaminated burgers. These include spices, domestic beef ingredients and imported beef ingredients (from Australia and New Zealand). The horses might have fled, but for damn sure, CFIA is going lock every door and window on the barn! Until the next time, that is.

I’m not suggesting that our food safety agencies are deliberately dilatory in their response to contamination. But we need to rethink our approach to prevention – and early detection – of foodborne disease. We need to apply the lessons from past failures, and take full advantage of the tools that are available. For example, Canada does not require provincial/territorial labs to post the genetic profiles of their E. coli cases on PulseNet Canada so that all labs across the country have access to this vital information. Yet, it was the absence of this very type of information that led, according to Dr. Low, to the delayed recognition of Canada’s deadly Listeria monocytogenes outbreak.

A couple of days ago, I contacted Dr. Richard Holley (University of Manitoba), one of Canada’s foremost food safety experts, for his perspective on this problem. He offered the following observation:

“We often hear public officials claim traceability is where resources/effort should be placed to protect us from foodborne illness (along with more inspection). In this outbreak “Officials acknowledged knowing about E. coli cases in Canada as early as October, but said they were not in a position to issue any recalls”. Greater emphasis on forensic clinical epidemiology would appear to be a more effective way to shorten exposure to contaminated food in the marketplace. If you look at the epidemiology curves of the two peanut butter outbreaks, the Mexican pepper, the DeCoster egg and German E. coli O104:H4 outbreaks, the outbreaks were almost over by the time the food causing each of these problems was identified and recalled. With the Cardinal Meats outbreak it has taken almost 3 months to identify garlic peppercorn hamburger as a vehicle.” 

“We need to get better,” Dr. Holley added, “at shortening the time before a recall is made and being sure we recall the right food/ingredient.”

In other words, we need a better D.E.W. line.