Media types looking for a sound bite on Listeria in cantaloupes are pulling their hair out tonight.

You couldn’t ask for a more complicated scenario. Advice like “wash your hands” or “cook your foods” or “don’t cross contaminate” is nearly worthless. Here are some troubling facts

Listeria monocytogenes:

• Psychrophilic, multiplication possible all the way to 29 degrees
• Ubiquitous, found in almost all environments, terrestrial and aquatic
• Found in feces of animals
• Most problematic in ready to eat foods
• Forms bio films on food prep surfaces that resist sanitizers, nearly impossible to remove once adhesion occurs
• Incubation period can be days to months
• Huge dose response curve, from 100 or less cells, to 1,000,000 or more
• High morbidity and mortality up to 50% of cases
• Some strains are pathogenic some are not
• Highly virulent strains may be emerging
• Targets immune-suppressed victims, fetuses, neonates, pregnant, those on immunosuppressive drugs, those with disorders of the liver, gut, blood
• Attaches to nervous tissues, systemic infections 

Cantaloupes:

• Rough netted exterior traps contaminants
• The rind surfaces of these melons likely can support adhesion as well as colonization by many pathogenic bacteria
• Melon meat is highly conducive to bacterial multiplication, rich in nutrients and moisture just below the rind
• Keeps well under refrigeration
• When cut, surface pathogens are transferred into the meat
   

Combine the two and you have a marriage made in hell.