It was the illustrious wartime leader, Winston Churchill, who said, “Those who fail to learn from history are doomed to repeat it.” With this in mind it was somewhat inevitable that the first major news stories of 2013 have been the outbreaks in Canada and Ohio linked to lettuce contaminated with E coli O157:H7. The industry falls back on the low incidence of pathogens on produce and the miniscule number of foodborne illness cases compared to the millions of bag salads sold daily. However, it is generally acknowledged that there are increasing concerns about the microbiological safety of leafy greens, especially bagged salad. One only has to review the growing list of recalls and outbreaks linked to leafy greens in 2012 to see that the industry in heading for a crisis.
So what do foodborne illness outbreaks have to do with sprouted seeds? Well, those in the produce sector have a tendency to distance themselves from sprouted seeds. There maybe some good reason for this, as sprouted seeds have and continue to be implicated in foodborne illness outbreaks linked to E coli O157:H7, Salmonella and occasionally Listeria monocytogenes. If we go back to leafy greens, the key outbreak that stimulated action and changes in the industry was that implicating E coli O157:H7-contaminated spinach that resulted in over 200 confirmed cases of illness along with 3 deaths. In the case of sprouts, the major outbreak occurred in Japan in 1996 involving radish sprouts contaminated with E coli O157:H7, resulting in over 6000 cases and 12 deaths. As one could imagine, this outbreak, along with others that occurred periodically, stimulated the government and industry to take action. Through various lines of research it was found that the seed used in sprout production was the source of human pathogens in 99% of cases. Consequently, it was proposed to use 20,000 ppm hypochlorite as a seed disinfection step even though it was recognized that the sanitizer was not totally effective at eliminating pathogens. Critically, the hypochlorite treatment was the only one recommended by the FDA guidelines published in 1999, and it become carved in stone. At the same time, the outputs of research were delivering more effective seed decontamination methods compared to hypochlorite. However, because they were not included in the sprout growers guidelines the industry turned their back on the new technologies.
In 2005 the FDA held a public meeting to review the sprout guidelines. here were several presentations relating to alternative seed disinfection methods. Yet, the FDA deemed that there was no need to revise the guidelines and the status quo persisted, as did the outbreaks. A few years later the FDA did take action by announcing that sprouts should be considered a high-risk food that should be avoided by susceptible groups. Faced with mounting pressure to fix the food safety issues with the industry, it might have been expected that sprout growers would consider introducing more effective seed decontamination methods. But no, the industry maintained its reliance on the ineffective hypochlorite seed disinfection method. It was almost as if they were oblivious to the outbreaks and recalls going on around them with an “it cannot happen to me” attitude. Even in the midst of the 2011 E coli O104:H4 outbreak linked to sprouted seeds in Germany, the industry in North America seemed to think such an outbreak could never happen here. What evidence they had to give such assurances was never elaborated upon.
The lack of positive action by the FDA and industry led major retail chains to remove sprouted seeds from the retail shelves on their own. The industry has been hit hard over the last decade with many sprout producers going to the wall. Those that have survived can see their market shrinking almost like a watering hole in the desert. Clearly, the lack of action on implementing intervention steps has cost the industry dearly.
So how does this relate to leafy greens and what lessons can be learned from the history of sprouted seeds? Well, the first is the increasing number of outbreaks linked to leafy greens and the inability of industry to do anything to control the problem. Yes, there are guidelines and warning letters, but these tend to dance around the problem, as opposed to tackling the food safety issue head-on. The post-harvest wash treatment for leafy greens is the main intervention step to remove field-acquired contamination. However, it was known back in 2001 that washing is relatively ineffective and can increase the problem by leading to cross-contamination between batches. Although more effective interventions have been developed for produce decontamination, the industry is reluctant to adopt new technologies. Sound familiar? Such technologies not only include irradiation but also gas phase treatments, those based on the advanced oxidative process and gas plasma technology. These are close to commercial application, although there is little confidence that industry will embrace them.
One could envision that the road back to market for sprouted seeds is going to be long and troublesome. The withdrawal of bagged salads from the supermarket shelves is a long way off, but how many foodborne illness outbreaks the market can take? Anyone can safely predict there will be several outbreaks and illnesses associated with leafy greens in 2013. It is time for the industry take action and implement effective post-harvest interventions rather than follow the decline of the sprouted seeds sector.© Food Safety News