The Intricacies of Whole Genome Sequencing: Epidemiologists Tracing Food

Whole Genome Sequencing (WGS) has quietly become one of the most transformative technologies in modern epidemiology, reshaping how public-health agencies detect, investigate, and ultimately prevent food-borne illness outbreaks. For decades, identifying the source of illnesses caused by pathogens like Salmonella , E. coli , Listeria monocytogenes , Campylobacter , and others relied primarily on classical microbiology paired with epidemiologic interviewing. While this approach frequently worked, it often left investigators with partial answers, long delays, or no definitive source at all. WGS changed that. By allowing scientists to decode the entire DNA sequence of a bacterial isolate, the tool provides a level of precision that was unimaginable during the era of PFGE-based surveillance . To