EV-D68 lineage tracked paralysis reports, then the link weakened
A genetic modelling study links one enterovirus D68 lineage to US reports of acute flaccid myelitis during several years before the pandemic. The association later weakened. Newly published in a peer-reviewed journal, the analysis also reconstructs seasonal circulation before the prominent 2014 outbreak, while changing surveillance complicates estimates of its scale.
Science··Midday
A lineage association changes after the pandemic
The circulation of one enterovirus D68 lineage tracked reports of acute flaccid myelitis in the US for several years; the association was weaker in the pandemic period and subsequently. The rare neurological condition may involve paralysis. The peer-reviewed genetic modelling study, newly published on October 23 after an earlier manuscript, compares viral histories with clinical surveillance rather than identifying the cause of individual patients’ symptoms.[1]
Public viral sequences from the 1990s through 2023 supplied the analysis, emphasising VP1, the region encoding a capsid protein. The main model focused on Europe and North America, where sampling supported comparison. The analysis combined branches A and D in one group, with B and C in another, then estimated how transmission changed over time.[1]
The reconstructed history showed seasonal transmission before the widely noticed 2014 respiratory outbreak. North American B plus C circulation, including B alone, correlated with paralysis reports in roughly 2014–2019. A plus D did not display the same sustained association. That difference describes a temporal pattern; it cannot establish the biological responsibility of a lineage.[1]
Changing surveillance affects estimates
Sequencing intensified after 2014, and the model allowed sampling effort to vary. Alternative sampling choices largely agreed on outbreak dates but gave different estimates of their size, which should not be read as infection counts. Europe lacked consistent monthly paralysis data for the same quantitative comparison. Linked clinical, genomic and wastewater surveillance could help distinguish changes in viral circulation from changes in observation.[1]
