Improved detection of Listeria monocytogenes outbreaks using whole genome sequencing, Gipuzkoa, Northern Spain, 2010 to 2022

This study represents one of the most comprehensive WGS‑based studies of listeriosis to date in Spain. Our findings demonstrate that more than one third of apparently sporadic cases were in fact part of persistent or recurrent genomic clusters, underscoring the hidden transmission potential of this pathogen. WGS analysis revealed links between cases that would not have been detected through routine epidemiology, providing critical insights into outbreak dynamics and long‑term circulation of L. monocytogenes. This regional study highlights the importance of implementing genomic surveillance for listeriosis and integrating all parts of the infection chain - from clinical diagnosis to food production and public health - to better guide responses and strengthen prevention and control strategies.