E. coli O157:H7 in Spinach - How it Got There

You'll probably remember that outbreak of E. coli O157:H7 linked to bagged baby spinach in September 2006 - the one that caused 205 cases of illness and 3 deaths in the United States and Canada. I've just finished reading the CDC report that details how E. coli O157:H7 might have been carried from cattle feces to the field of baby spinach one mile away.

The report explains that the same pathogen that was responsible for the illnesses was found in cattle feces, in feral (wild) swine, in samples of surface water and in soil samples. The authors of the report suggest that feral swine might have carried E. coli O157:H7 from the cattle to the spinach fields.

This is not news - CDC released that information many weeks ago. But there are a couple of tidbits buried in the official published report that are worth noting:

1. There were four ranches suspected of being the source of the September 2006 food poisoning outbreak. Only one of these was found to be contaminated with the outbreak strain of E. coli O157:H7. But fields on the other three ranches were also contaminated with E. coli O157 - just not the strain that caused this particular outbreak.
2. Mechanical harvesting was probably a contributor to the outbreak. The reports states: "Notably, baby spinach is harvested with a lawn mower–like machine that could pick up fecal deposits in the field and thereby contaminate large volumes of product during processing."

The bottom line is that there will be more outbreaks. We have allowed a deadly pathogen to spread through a major agricultural area. And by maximizing "efficiency" through the use of this type of mechanical harvesting equipment, we are increasing the likelihood that E. coli O157:H7, Salmonella, and any other pathogens that may be lurking in the soil will find their way into our salad bowls.