Evolutionary phylogeography and transmission pattern of echovirus 14: an exploration of spatiotemporal dynamics based on the 26-year acute flaccid paralysis surveillance in Shandong, China.

BACKGROUND: Echovirus 14 (E-14) causes various clinical recognized syndromes, mostly with gastrointestinal syndrome and paralysis. The current study summarized the Shandong E-14 strains isolated from a 26-year acute flaccid paralysis (AFP) surveillance, and elucidated the characterization of phylogenetic and phylogeographic relationships of E-14 worldwide.

RESULTS: As a predominant serotype circulating in AFP surveillance, phylogenetic analysis showed that E-14 exhibited both time and geographic subdivision worldwide. In order to know the evolutionary history and spatial temporal dynamics of E-14, evolutionary phylogeography was reconstructed using BEAST and SPREAD software based on the VP1 sequences. The time of the most recent common ancestor of E-14 was estimated around 85 years and evolved with 9.17 × 10-3 substitutions/site/year. Phylogeographic analysis suggested that two regional transmissions of E-14 were mainly detected, with one located between Europe and Africa countries and the other was in the Asia-Pacific region.

CONCLUSIONS: Our study investigates the molecular evolution and phylogeographic of E-14, and brings new insight to the dispersal of E-14 worldwide. Regional transmission was mainly detected and Australia may be responsible for the spread of E-14 in recent years.