Leafy greens have become one of the most common sources of food poisoning outbreaks in the US, a new study says.  What’s more, research suggests the growing number of food borne illnesses associated with lettuce, spinach and other greens cannot simply be attributed to Americans’ growing love of salads.

In the past several years, outbreaks of E. coli and Salmonella from fresh vegetables have become an increasing problem.  In fact, one of the biggest E. coli outbreaks in recent years was attributed to fresh spinach.  In September 2006, bagged fresh baby spinach sold by the Dole Food Company was linked to an E. coli outbreak that was blamed for the deaths of three people and illness in 200 others. Since then, several other recalls of E. coli contaminated lettuce and other greens have made headlines.

Such outbreaks have prompted the Centers for Disease Control (CDC) to study the frequency of leafy green-related food poisoning incidents.  To that end, the CDC analyzed data from its food borne disease outbreak surveillance system reported between 1973 and 2006.  The CDC findings were reported earlier this week at the International Conference on Emerging Infectious Diseases in Atlanta.

According to the CDC, of the 10,421 food borne disease outbreaks reported during the 13-year period, 502 (4.8 percent) were associated to leafy greens. Most of these outbreaks (58.3 percent) involved Norovirus, followed by Salmonella (10.4 percent) and E. coli (8.9 percent).

The increase in food poisoning incidents tracked back to leafy greens was well ahead of the increase in the consumption of such vegetables seen during the same 13 year period.  According to the study’s abstract, “during 1986-1995, US leafy green consumption increased 17.2 percent from the previous decade. During the same period, the proportion of all food borne disease outbreaks due to leafy greens increased 59.6 percent.  Likewise, during 1996-2005 leafy green consumption increased 9.0 percent and leafy-green associated outbreaks increased 38.6 percent.” The CDC researchers said that these numbers indicate that the rise in such food poisoning incidents can’t be seen as a consequence of Americans consuming more greens.

What this means is that pathogens like E. coli and Salmonella are contaminating lettuce, spinach and other greens either while they are still in fields or at processing plants. The 2006 Dole spinach outbreak, for example,  was traced to a cattle ranch adjacent to the California field where the spinach was grown. It is believed that runoff from the ranch that was contaminated with cattle feces made its way into the spinach field.   The CDC’s research is yet more evidence that growers and processors have to take stronger measures to protect the public from tainted produce.

This entry was posted on Wednesday, March 19th, 2008 at 11:55 am and is filed under Food Poisoning, Legal News.