Recent parechovirus A3 (PeV-A3) outbreaks in Australia suggest lower population immunity compared with regions that have endemic PeV-A3 circulation. A serosurvey among populations in the Netherlands, the United States, and Australia before and after the 2013 Australia outbreak showed high PeV-A3 neutralizing antibody prevalence across all regions and time periods, indicating widespread circulation.
Keywords: Australia; Picornaviruses; United States; neutralizing antibody; outbreak; parechovirus A3; seroepidemiology; seroprevalence; the Netherlands; viruses.