HPeV3 diversity, recombination and clinical impact across 7-years: an Australian story
Seweryn Bialasiewicz, Meryta May, Sarah Tozer, Rebecca Day, Anne Bernard, Julian Zaugg, Kyana Gartrell, Soren Alexandersen, Anthony Chamings, Claire YT Wang, Julia Clark, Keith Grimwood, Claire Heney, Luregn Schlapbach, Robert S Ware, David Speers, Ross M Andrews, Stephen Lambert
The Journal of Infectious Diseases, jiac311, published 22 July 2022. DOI: https://doi.org/10.1093/infdis/jiac311
A novel human parechovirus 3 Australian recombinant (HPeV3-AR) strain emerged in 2013 and coincided with biennial outbreaks of sepsis-like illnesses in infants. We evaluated the molecular evolution of the HPeV-AR strain and its association with severe HPeV infections.
HPeV3-positive samples collected from hospitalized infants aged 5–252 days in two Australian states (2013–2020) and from a community-based birth cohort (2010–2014) were sequenced. Coding regions were used to conduct phylogenetic and evolutionary analyses. A recombinant-specific PCR was designed and utilized to screen all clinical and community HPeV3-positive samples.
Complete coding regions of 54 cases were obtained, which showed the HPeV3-AR strain progressively evolving, particularly in the 3’ end of the non-structural genes. The HPeV3-AR strain was not detected in the community birth cohort until the initial outbreak in late 2013. High-throughput screening showed most (>75%) hospitalized HPeV3 cases involved the AR strain in the first three clinical outbreaks, with declining prevalence in the 2019-20 season. The AR strain was not statistically associated with increased clinical severity amongst hospitalised infants.
The HPeV3-AR was the dominant strain during the study period. Increased hospital admissions may have been from a temporary fitness advantage and/or increased virulence.