Parechoviruses are assumed to be common infectious agents, but their epidemiologic and pathogenic properties are not well known. The aim of the present study was to assess the prevalence and molecular epidemiology of Parechovirus in Norwegian infants, as well as to investigate whether the presence of virus correlated with symptoms of infection. A group of 102 infants was longitudinally followed: 51 infants with a high genetic risk for type 1 diabetes (aged 3–35 months), and 51 children without this genotype (aged 3–12). Stool samples were obtained each month, and symptoms of infection were recorded regularly on questionnaires. Human parechovirus was detected in 11.3% of 1,941 samples examined by real‐time RT‐PCR. There was a distinct seasonality, peaking from September to December. By 12 months of age, 43% of the infants had had at least one infection, while 86% of the infants had encountered the virus by the end of the second year. Based on the VP1 sequence, human parechovirus 1 was the most prevalent type (76%), followed by human parechovirus 3 (13%), human parechovirus 6 (9%), an unclassified human parechovirus (1%), and human parechovirus 2 (1%). Ljungan virus, a murine parechovirus, was examined with a separate real‐time RT‐PCR, but no virus was detected. There was no significant association between infections and the following symptoms: coughing, sneezing, fever, diarrhea or vomiting. In conclusion, human parechovirus infects frequently infants at an early age without causing disease. J. Med. Virol. 80:1835–1842, 2008. © 2008 Wiley‐Liss, Inc.

Human enterovirus (HEV) infections can be asymptomatic or cause only mild illness; recent evidence may implicate HEV infection in type 1 diabetes mellitus and myocarditis. Here, we report the molecular characterization of HEV obtained in serial monthly collections from healthy Norwegian infants. A total of 1,255 fecal samples were collected from 113 healthy infants beginning at age 3 months and continuing to 28 months. The samples were analyzed for HEV nucleic acid by real-time PCR. Fifty-eight children (51.3%) had HEV infections. One hundred forty-five positive samples were typed directly by nucleotide sequencing of the VP1 region. HEV-A was detected most frequently, with an overall prevalence of 6.8%. HEV-B was present in 4.8% of the samples and HEV-C in only 0.2% of the samples. No poliovirus or HEV-D group viruses were detected. Twenty-two different serotypes were detected in the study period: the most common were EV71 (14.5%), CAV6 (10.5%), CAV4 (8.9%), E18 (8.9%), and CBV3 (7.3%). These findings suggest that the prevalence of HEV infections in general, and HEV-A infections in particular, has been underestimated in epidemiological studies based on virus culture.

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OBJECTIVETo test whether the frequency of human enterovirus RNA in fecal samples collected monthly from early infancy was associated with development of multiple islet autoantibodies in children with the highest risk HLA genotype.RESEARCH DESIGN AND METHODSIndividuals carrying the HLA DRB1*0401-DQA1*03-DQB1*0302/DRB1*03-DQA1*05-DQB1*02 genotype were identified at birth and followed with monthly stool samples from age 3 to 35 months. Blood samples taken at age 3, 6, 9, and 12 months and then annually were tested for autoantibodies to insulin, GAD 65 and IA-2. Among 911 children, 27 developed positivity for two or more islet autoantibodies in two or more consecutive samples (case subjects). Two control subjects per case subject were matched by follow-up time, date of birth, and county of residence. Stool samples were analyzed for enterovirus with a semiquantitative real-time RT-PCR.RESULTSThe frequency of human enterovirus RNA in stool samples from case subjects before seroconversion (43 of 339, 12.7%) did not differ from the frequency in control subjects (94 of 692, 13.6%) (P = 0.97). Results remained essentially unchanged after adjustment for potential confounders, restriction to various time windows before seroconversion, or infections in the 1st year of life or after inclusion of samples collected after seroconversion. There was no difference in the average quantity of enterovirus RNA or in the frequency of repeatedly positive samples. The estimated relative risk for islet autoimmunity per enterovirus RNA–positive sample during follow-up (nested case-control analysis) was 1.12 (95% CI 0.66–1.91).CONCLUSIONSThere was no support for the hypothesis that fecal shedding of enteroviral RNA is a major predictor of advanced islet autoimmunity.

Self-reported lower respiratory tract infections were associated with increased risk of islet autoimmunity in early infancy.