Novel Human Parechovirus 3 Diversity, Recombination, and Clinical Impact Across 7 Years: An Australian Story

Clinical presentation and management of enterovirus and parechovirus infection in children: A single-centre study in regional Australia

OBJECTIVE

This study aims to analyse the clinical presentation caused by enterovirus (EV) and/or human parechovirus (HPeV) infection in children, as well as the management of such cases admitted to a regional hospital in Australia.

METHODS

Retrospective study reviewing medical records.

SETTING

Single hospital in regional Australia.

PARTICIPANTS

All children under 18 years admitted over the 5-year period beginning from 1 January 2017 with confirmed EV and/or HPeV infection. Cases with clinically insignificant EV/HPeV isolation were excluded.

MAIN OUTCOME MEASURES

Data collected included demographic data, signs and symptoms present, specimens of EV/HPeV isolation, co-occurring pathogens, peak C-reactive protein (CRP), antibiotic therapy, discharge diagnosis and follow-up after discharge.

RESULTS

Overall, 27 patients fulfilled the inclusion criteria; 81.5% of the patients were ≤3 months of age with a median of 2 months (interquartile range 1-3); 74.1% were males. The most common clinical features were a fever ≥38°C and irritability/lethargy/high-pitched cry. 29.6% of the patients had co-occurring pathogens detected, and a CRP ≤10 mg/L was observed in 77.8% of cases. All but two children were treated with antibiotics while awaiting polymerase chain reaction results. The most common discharge diagnosis was meningitis. In all, 74.1% of the children attended follow-up appointments.

CONCLUSIONS

EV and HPeV should be considered as a possible aetiology of fever and irritability/lethargy/high-pitched cry in children under 3 months.

First whole genome sequencing and analysis of human parechovirus type 3 causing a healthcare-associated outbreak among neonates in Hungary

PURPOSE

In November 2023, the National Reference Laboratory for Enteroviruses (Budapest, Hungary) received stool, pharyngeal swab and cerebrospinal fluid samples from five newborns suspected of having human parechovirus (PEV-A) infection. The neonates were born in the same hospital and presented with fever and sepsis-like symptoms at 8-9 days of age, and three of them showed symptoms consistent with central nervous system involvement. PEV-A positivity was confirmed by quantitative reverse transcription polymerase chain reaction.

METHODS

To determine the PEV-A genotype responsible for the infections, fecal samples of four neonates were subjected to metagenomic sequencing. For further analyses, amplicon-based whole genome sequencing was performed directly from the clinical samples.

RESULTS

On the basis of whole genome analysis, sequences were allocated to PEV-A genotype 3 (PEV-A3) and consensus sequences were identical. Two ambiguities were identified in the viral protein 1 (VP1) region of all sequences at a frequency of 17.7-53.7%, indicating the simultaneous presence of at least two quasispecies in the clinical samples. The phylogenetic analysis and similarity plotting showed that all sequences clustered without any topological inconsistencies between the P1 capsid and P2, P3 non-capsid regions, suggesting that recombination events during evolution were unlikely.

CONCLUSION

Our findings suggest that the apparent cluster of cases were microbiologically related, and the results may also inform future investigations on the evolution and pathogenicity of PEV-A3 infections.