Today’s announcement that Lois Tufly, a 91-year-old woman from Colorado, may be the latest victim of the devastating cantaloupe Listeria outbreak, probably makes lots of people wonder why so many have died, and so many others have been hospitalized, in this Listeria outbreak.  To date, the CDC recognizes 8 deaths from Colorado, New Mexico, Kansas, Nebraska, Oklahoma and Maryland.  By our count, the actual number is likely 12.

To begin with, Listeria is an opportunistic organism.  Depending partially on the amount of bacteria ingested, otherwise healthy adults may not even get sick.  But for an unlucky few, including pregnant women and the elderly, the bacteria takes root, becomes bloodborne or infects one of the body’s organs, and causes severe illness.  Oftentimes in the elderly, Listeria infection produces symptoms that include shaking or convulsing, disorientation, and even a paralysis-like inability to control certain muscular functions. 

But the elderly–our firm represents at least 20 families in this outbreak, and nearly all of them are elderly folks–have a couple of strikes against them even without other medical problems for the bacteria to take advantage of.  

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 Listeria 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.