L. monocytogenes serotype 4b strains are responsible for 33 to 35% of sporadic human cases worldwide and for all major foodborne outbreaks in Europe and North America since the 1980s.
As cepas do serotipo 4b de L. monocytogenes son responsables dos principais casos de enfermidades de orixe alimentaria humanas en Europa e Norteamérica e de entre o 33 e o 50 % dos casos esporádicos no mundo desde a década de 1980.