There's no definitive reason why children are afflicted with type 1 diabetes, a disease where the immune system accidentally attacks insulin-producing cells in the pancreas causing them to become diabetic.

In order to eliminate one possible environmental reason from the list, a joint U.S. and European consortium has looked into the possibility of viruses instigating some already known genetic factors that cause diabetes in kids.

The researchers screened 420,000 infants that were younger than 4.5 months between 2004 and 2010 for genetic markers known to predispose children to developing type 1 diabetes. Families were asked to provide detailed information on childhood infections, diet, and developmental data in an attempt to peg down an environmental factor that might initiate type 1 diabetes in children.

Of the initial group, 8.677 children were enrolled in the study and 932 of the children had a parent or sibling that was affected by type 1 diabetes and the rest had no family history. Parents brought the children to a clinic every three months for blood tests until the child was four years of age to detect markers of beta cell autoimmunity (antibodies against islet cell antigens), if the child was infected by a virus and other measures.

Of the 8,677 children enrolled, 355 developed antibodies against islet cell antigens and 86 children in that group progressed to type 1 diabetes by July 2011. The time from detecting autoimmune antibodies to the onset of diabetes was quick, within six months, in 24 of the children.

Researchers then analyzed blood samples taken before and after the detection of autoimmune antibodies and found no presence of viruses using state-of-the-art sequencing technologies. This technology would find not only any known viruses, but all viruses regardless of its knowledge to science.

"These findings cannot exclude the possibility that a causative virus is acquired before the age of 6 months and absent or only present for a brief time in plasma during the months leading to the appearance of beta-cell autoantibodies and progression to diabetes. However, the findings make us again reflect on whether a virus triggers type 1 diabetes," said Professor Anette-Gabriele Ziegler from the German Research Center for Environmental Health in Munich.

The research was published in Diabetologia, the journal of the European Association for the Study of Diabetes (EASD) and can be read here (PDF).