The following is a summary of “Novel Human Parechovirus 3 Diversity, Recombination, and Clinical Impact Across 7 Years: An Australian Story,” published in the January 2023 issue of Infectious Diseases by Bialasiewicz, et al.

In 2013, a brand-new strain of the human parechovirus 3 Australian recombinant (HPeV3-AR) appeared, timed with baby sepsis-like sickness epidemics every two years. For a study, researchers sought to determine the HPeV3-AR strain’s molecular development and relationship to serious HPeV infections.

Sequencing was done on HPeV3-positive samples taken from a community-based birth cohort (2010-2014) and from hospitalized babies aged 5-252 days in 2 Australian states (2013-2020). In addition, phylogenetic and evolutionary studies were performed on coding areas. All clinical and community HPeV3-positive samples were screened using a polymerase chain reaction specifically developed for recombinant DNA.

They were able to extract the whole coding area for 54 instances, demonstrating how the HPeV3-AR strain has been steadily developing, especially towards the 3′ ends of the nonstructural genes. The community birth cohort did not have the HPeV3-AR strain until the initial outbreak in late 2013. According to high-throughput screening, the AR strain was implicated in the majority (>75%) of hospitalized HPeV3 patients in the first three clinical outbreaks, with decreasing incidence in the 2019–2020 season. However, the AR strain was not statistically linked to higher clinical severity in hospitalized newborns.

Throughout the time of the research, HPeV3-AR was the predominant strain. However, a brief fitness advantage and/or heightened pathogenicity increased hospital admissions.

Reference: academic.oup.com/jid/article/227/2/278/6648722