strawberry.bmpE. coli contaminated strawberries are the cause of a lethal foodpoisoning outbreak that has sickened at least 10 northwest Oregon residents and caused the death of 1 elderly woman.  The strawberries were grown at Jaquith Strawberry Farm in Newberg, Oregon.  The illnesses occurred in July, and the farm at which the contaminated berries were grown and harvested is no longer producing fruit.

With relatively limited shelf-life, the contaminated berries are likely no longer a threat unless they have been frozen or made into products like uncooked jam.  Strawberries, according to a quick search on www.outbreakdatabase.com, have been the vehicle, or suspected vehicle, for foodpoisoning on multiple occasions before.  

Unfortunately, the Oregon strawberry E. coli outbreak offers yet another opportunity to examine why it is that the elderly are more susceptible to severe foodpoisoning illnesses than other adults.  First, the aging of their gastrointestinal tracts reduces peristalsis, or the natural ability of the GI tract to propel contents through and out the system. This delayed clearance of food, and the bacteria that they contain, means longer periods of contact between the bacteria and the lining of the GI tract. This gives the bacteria more time to do their ugly job before being shed from the system. Second, the elderly, as a group, have a higher incidence of co-morbidities (i.e. other illnesses or conditions), which presents a host of medical problems and threats in the context of a severe salmonella infection.

Finally, with advancing age come progressive weakness, decline, and dysfunction of the immune system. Many of the body’s natural physiologic responses to infection are therefore blunted in the elderly; and the intensity of many clinical signs and symptoms in an elderly patient with an infectious process are muted when compared to those in a younger person. This age-related decline contributes significantly to the increased risk of severe illness and mortality in elderly persons with infectious disease.