Transcontinental spread of Vibrio parahaemolyticus sequence type 36, North America, Peru, and Spain, 1985–2016. Timeline was estimated by using BEAST (Bayesian evolutionary analysis by sampling trees). Years on map indicate the inferred dates of arrival of V. parahaemolyticus sequence type 36 to that country. Old Pacific Northwest is the ancestral population (last strain identified in 2002) of the Pacific Northwest lineage complex, which also includes the modern (i.e., currently circulating) Pacific Northwest lineage, Pacific Northwest lineage 2, Atlantic Northeast lineage, and the South America–West Europe group.