Seroprevalence of parechovirus A1, A3 and A4 antibodies in Yamagata, Japan, between 1976 and 2017

Abstract

Introduction. Although new parechovirus A (PeVA) types, including parechovirus A3 (PeVA3) and PeVA4, have been reported in this century, there have not yet been any seroepidemiological studies on PeVA over a period of several decades. Hypothesis/Gap Statement. The authors hypothesize that PeVA3 and PeVA4 emerged recently. Aims. The aim was to clarify changes in the seroprevalence of PeVA1, PeVA3 and PeVA4. Methodology. Neutralizing antibodies (NT Abs) were measured among residents in Yamagata, Japan in 1976, 1983, 1985, 1990, 1999 and 2017. Results. The total NT Ab-positive rate for PeVA1 was between 90.7 and 100 % for all years analysed, with that for PeVA3 increasing from 39.6 % in 1976 to 69.6 % in 2017, and that for PeVA4 decreasing from 93.9 % in 1976 to 49.1 % in 2017. The distribution of NT Ab titres for PeVA1, PeVA3 and PeVA4 among those aged less than 20 years old was as follows: those ≥1 : 32 for PeVA1 were between 68.0–89.2 % for all years analysed; those ≥1 : 32 for PeVA3 was 15.4 % in 1976, 44.3–54.9 % in 1983–1990 and 64.8–68.0 % in 1999–2017; and those ≥1 : 32 for PeVA4 were between 49.1–67.2 % in 1976–1990, 41.3 % in 1999 and 23.8 % in 2017. Conclusions. Our findings in this seroepidemiological study over four decades suggested that PeVA1 has been stably endemic, while PeVA3 appeared around 1970s and has spread since then as an emerging disease, and occasional PeVA4 infections were common in 1970s and 1980s but have been decreasing for several decades in our community.

Longitudinal antigenic and seroepidemiological analyses of parechovirus A1 in Yamagata, Japan

“…A total of 62 PeVA1 strains were isolated in Yamagata between 2001 and 2021 from young children; 31 from 0‐year‐olds, 25 from 1‐year‐olds, 2 from 2‐ or 3‐year‐ olds, and 3 from 4‐, 5‐ or 6‐year‐olds, respectively (Supporting Information: Table ). These findings, and our previous seroepidemiological studies showing high NT‐Ab positive rates in young children, indicated that residents in Yamagata have been infected with PeVA1 at a young age 10,11 . All PeVA1 strains in this study were isolated from children under 6 years of age with common infectious diseases.…”

“…15,16 On the other hand, previous seroepidemiological studies between 1978 and 2017 in Yamagata suggested that PeVA1 had been in circulation stably over several decades, as a high neutralizing antibody (NT-Ab)-positive rates (more than 88% in residents 6 years or older) were found during the study period. 10,11 These seroepidemiological studies also provided the basis for our hypothesis that there had been no major change in PeVA1 antigenicity for a long time. Furthermore, our previous studies of enterovirus A71 (EV-A71) and coxsackievirus A6 (CV-A6) indicated that there was cross-antigenicity among different genomic lineages and/or subgenogroups including the prototype strain and recent Yamagata strains.…”

“…PeVA1 often causes mild respiratory or gastrointestinal symptoms in infants, whereas a few cases of severe diseases such as encephalitis, acute flaccid paralysis, and myocarditis due to PeVA1 have been reported 1,3 . Virological detection analysis as well as seroepidemiological studies support the fact that PeVA1 infection occurs early in infancy 3,6–14 …”

Seroprevalence of coxsackievirus A21 neutralizing antibodies in Yamagata, Japan, between 1976 and 2019; coxsackievirus A21 has rarely affected young children

“…Serum samples were collected from residents in Yamagata, from whom informed consent was obtained (either from the individual or guardian) from 2000, and from those without informed consent before 2000, when the need for informed consent was not yet strictly applied. In this study, serum specimens collected in 1976, 1985, 1999, 2009, and 2019, most of which were used in our previous seroepidemiological study against parechoviruses, 20 were used and the numbers enrolled for each year in each age group are shown in Table 1. This study was approved by the Ethics Committee of the Yamagata Prefectural Institute of Public Health (YPIPHEC 20‐03).…”

“…NT Ab titers were measured in a similar manner to our previous studies using microneutralization testing 20 . Briefly, the Yamagata representative CV‐A21 strain “1652‐Yamagata‐2019,” whose sequence was registered under GenBank accession number LC533361 in our previous study, 17 was used as the challenge virus antigen and RD‐18S cell line was used.…”