Human parechovirus 1 infections in young children—no association with type 1 diabetes

Abstract

The epidemiology, transmission and clinical symptoms of human parechoviruses [HPeV, classified earlier as enteroviruses; echovirus 22 (HPeV1) and echovirus 23 (HPeV2)] remain poorly characterized. Enteroviruses and one parechovirus species, the Ljungan virus, have been associated with type 1 diabetes in humans and rodents. The occurrence of human parechovirus 1 (HPeV1) infections in young children and their possible association with type 1 diabetes was evaluated. The prospective birth cohort study comprised 221 Finnish children carrying genetic type 1 diabetes susceptibility and who were observed from birth. Thirty-four children developed multiple diabetes-associated autoantibodies, and 18 children progressed to clinical type 1 diabetes during the follow-up. HPeV1 infections were diagnosed by measuring neutralizing antibodies from the follow-up sera taken every 3-12 months. In addition, viral RNA was analysed by RT-PCR from stool samples taken every month from six of the participants. HPeV1 infections were found to occur early in childhood. The median age of infection was 18 months and 20% of the children had had an infection by the age of 1 year. The number of infections started to increase from the age of 6 months and most children had their first infection by 36 months. Nearly all (99%) mothers were HPeV1 antibody positive. No difference was found in infection frequency between boys and girls, nor between prediabetic, diabetic and control subjects. Most infections (87%) occurred during autumn, winter and spring.

Genetic Testing of Newborns for Type 1 Diabetes Susceptibility – The MIDIA Study

“…Ljungan virus has earlier been shown to cause diabetes-like condition in rodents (Niklasson et al, 2006), but was not identified in samples from children in our studies (Tapia et al, 2008, Tapia et al, 2010. HPeV1 has been reported to show no association with T1D (Tauriainen et al, 2007), but there is no data on the other types of HPeVs. However, sequencing should be done to see if there is any difference in strains, and to test for all the new human Parechoviruses.…”

Human Parechoviruses, New Players in the Pathogenesis of Viral Meningitis

“…Data on seroprevalence in neonates are not available, but the seroprevalence rate for children between 7-12 months is 15% which steadily increases to 91% in adolescent adults only to decline again to 56-87% in adults. This is in contrast to what is seen for HPeV1 where over 97% of adults still have antibodies against HPeV1 (Joki- Korpela & Hyypia, 1998;Tauriainen et al, 2007). Interestingly, seroprevalence among adults in the childbearing age (20-39 years) is the lowest (57-74%) (Ito et al, 2004).…”

“…The seroprevalence decreased after 6 months of age, only to rapidly increase among children older than 1-3 year of age to 95%. The low seropositivity from 6 months to 1-3 years is marked by an increase in infection frequencies among children in this age group, (Benschop et al, 2006a;Joki-Korpela & Hyypia, 1998;Stanway et al, 2000;Takao et al, 2001;Tauriainen et al, 2007). Seroprevalence rates among adults remained stable at 97-99% (Joki-Korpela & Hyypia, 1998;Stanway et al, 2000;Tauriainen et al, 2007).…”

“…In contrast to HPeV3, HPeV1 circulates every year in high numbers in the fall and winter months in Europe and Asia (Benschop et al, 2006a(Benschop et al, , 2008c(Benschop et al, , 2010aEhrnst & Eriksson, 1993;Tauriainen et al, 2007;Watanabe et al, 2007). The same is described for HPeV4 and 6 (Benschop et al, 2008c(Benschop et al, , 2010aHarvala et al, 2008;Pajkrt et al, 2009).…”

“…This age difference in relation to the disease severity between the two HPeV types suggests that neonates in comparison to older children might be less protected against HPeV3 infection. Seroprevalence data showed that 95-99% of neonates had antibodies against HPeV1 which is most likely to be maternal (Joki-Korpela & Hyypia, 1998;Nakao et al, 1970;Stanway et al, 2000;Takao et al, 2001;Tauriainen et al, 2007). The high HPeV1 seroprevalence thus suggests that the majority of infants should be www.intechopen.com protected from HPeV1 infection early in life via maternal protection.…”