Severe Human Parechovirus Infections in Infants and the Role of Older Siblings

Abstract

Human parechovirus (HPeV) is a cause of severe morbidity among infants and young children. To evaluate the associations between early environmental risk factors and HPeV infections, we carried out a nationwide cohort study linking registry data on birth and sibship characteristics with a laboratory surveillance database, covering all HPeV infections detected in Denmark during 2009-2012 among children <5 years of age. Incidence rate ratios were calculated in log-linear Poisson regression analyses. Overall, 133 HPeV infections, 85 caused by human parechovirus type 3 (HPeV-3) and 48 by human parechovirus other than type 3 (non-HPeV-3), were detected among 132 children. Neither birth weight, mode of delivery, Apgar score, nor gestational age was associated with the risk of HPeV infections. Compared with firstborn children, secondborn children were at a 9-fold increased risk (incidence rate ratio = 8.68, 95% confidence interval: 3.85, 19.53) of contracting HPeV-3 infections, but at no increased risk of contracting non-HPeV-3 infections. However, the shorter the age gap to the nearest older sibling, the higher the risk of HPeV-3 as well as non-HPeV-3 infections, although the trend was strongest for HPeV-3 infections. Our study is the first to suggest that having a slightly older sibling increases the risk for severe neonatal HPeV infections. This new knowledge might lead to new preventive measures.

Parechovirus A Infections in Healthy Australian Children During the First 2 Years of Life: A Community-based Longitudinal Birth Cohort Study

“…PeV-A1 detections occurred earlier than PeV-A3, agreeing with seroprevalence findings [10,11], but conflicting with RT-PCR-based studies [11,31]. However, the RT-PCR studies relied upon clinical samples, which may bias the PeV detection ages as PeV-A3 is associated primarily with disease before age 3 months [2,3,5,7,11].…”

“…The overall PeV incidence rate was 144 (95%CI, 128-161) episodes per 100 child-years. Incidence rates for the 3 major types (PeV-A types 1, 3, and 6) were 64 (95% CI, 54-75), 24 (95% CI, [19][20][21][22][23][24][25][26][27][28][29][30][31][32], and 27 (95% CI, 21-35) episodes per 100 childyears, respectively. After the first 3 months of life, the incidence of new PeV infections rose steadily until age 8 months before plateauing and then gradually declining in the second year ( Supplementary Figure 4).…”

Parechovirus: an important emerging infection in young infants

“…In the community, non‐hospitalised, confirmed cases should avoid contact with other young children (including childcare and school attendance) until symptoms have fully resolved. Contacts of confirmed cases should be made aware that older children and adults may develop mild upper respiratory or diarrhoeal symptoms 39 . There are cases of transmission from mildly symptomatic children to adults resulting in severe acute illness, but these appear to be uncommon 34 .…”

Evolutionary and network analysis of virus sequences from infants infected with an Australian recombinant strain of human parechovirus type 3

“…The reason for this is not known and as these viruses are easily transmitted by the oral-faecal and respiratory routes 30 , it may be related to exposure and immunity within families e.g. outbreaks occurring when there is both an older sibling lacking prior HPeV3 exposure plus waning or no maternally derived HPeV3 passive immunity in the young infant 30, 34 . Studies from Japan have indicated that antibodies to HPeV3 are only present in 15% of children from 7 months to 1 year of age, but that seropositivity increases to 45% in 2–3 year old and to 85% in 4–6 year old children 11, 35 .…”