Clinical manifestations in children with parechovirus A and respiratory tract infection

Background: The role of parechovirus A (PeV-A) in respiratory tract infections (RTI) in children remains unclear. Objectives and methods: We used clinical and virological data from two observational studies to study PeV-A in RTIs in children: a study of children admitted to hospital with RTI, and a study of children examined for RTI while attending day care centres. All had clinical examination and one nasopharyngeal aspirate analysed for PeV-A and 18 other viruses and bacteriae by culture and PCR-tests. Results: In the hospital study 4.6% (15/323) PeV-A positive RTIs were single virus detections. In 95.4% (308/323) other viruses were co-detected, including 28 with PeV-A and respiratory syncytial virus (RSV) and 77 with PeV-A and human rhinovirus (HRV). Multivariable logistic regression analysis showed strong association between single PeV-A and upper RTI (URTI) vs. lower RTI (LRTI) (age-adjusted OR 11.3, 95% CI 3.1-41.3). By retrospective evaluation of medical records, PeV-A was a likely cause of mainly pharyngitis and tonsillitis in 10/15 children with single PeV-A. In multivariable logistic regression modelling the presence of PeV-A had no impact on clinical manifestations and short-term outcomes in children with codetected RSV and HRV. In the day-care study PeV-A was detected in 30 children, among who 8/10 with single PeV-A had pharyngitis and tonsillitis. Conclusion: Single PeV-A detection was associated with pharyngitis and tonsillitis among children in day-care and hospital. Most hospitalized children with PeV-A had LRTI and viral codetections, but the presence of PeV-A did not impact disease severity in those with RSV and HRV.