With each passing poultry-associated Salmonella outbreak over the past few years, there has been an increased focus on this pathogen and its control. Along with that is an increasing use of the term “virulent.” But what does virulent really mean, and should we worry about some strains being more virulent than others? Does evading mitigation in processing make a pathogen “more virulent,” as some seem to indicate? Does the fact that a strain is antibiotic resistant define it as more virulent? As we look at how the term “virulent” is being used by the public health community, regulators, consumer groups and others – often extending beyond the molecular and clinical definition – what impact will this have on food processors and future policy measures?
To go back to the beginning: To understand the conundrum, we need to first understand what we mean by virulent, and ensure that everyone is using the same definition. Right now we’re not all on the same page. As defined in relation to pathogens by the Miriam Webster Medline dictionary, virulent is “able to overcome bodily defense mechanisms.” Or, in simpler terms – able to make you sick. Overcoming bodily defense mechanisms is different than overcoming food industry or consumer mitigations (like high pressure or cooking). It’s different than resisting clinical treatments (like antibiotics). But recent statements equating virulence with antibiotic resistance, or suggesting that resistance to heat results in increased virulence, begins to blur these issues together. This has caused confusion and could lead some down the wrong path to finding a solution that reduces illness.