Norway is among the countries with the highest prevalence of type 1-diabetes, and the incidence is increasing. Both environmental- and genetic factors contribute to development of the disease; but no environmental risk factor for type 1-diabetes has been identified, and it is therefore difficult to prevent the disease. In the prospective research study MIDIA (Norwegian acronym for Environmental triggers of type 1-diabetes) 100,000 new-borns will be tested for a gene combination that approximately 2.1% of the children have. Each of the 2,100 children with this combination have a 6-10% risk for childhood diabetes. They will be followed for up for 15 years with regular stool samples, questionnaires and blood samples with the aim of finding causes of diabetes. Detection of autoantibodies towards beta cells in the pancreas indicates an ongoing disease process and will be used as the first end-point. The aim of this article is to inform Norwegian doctors about the study, and to discuss scientific and ethical aspects of the project.
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.