It was earlier reported the finding that the incidence of type 1 diabetes correlates with small rodent abundance in Sweden. This and other findings initiated an effort to isolate novel infectious agents from small rodents in an attempt to find an etiological agent for type 1 diabetes in humans. As a result of these efforts, a new picornavirus (Ljungan virus [LV]) was isolated from bank voles trapped in Sweden. Moreover, it has been shown that more than one-third of wild-caught bank voles and their offspring develop diabetes when kept under laboratory conditions. This was accompanied by changes in pancreatic islet structure, islet cells becoming immunohistochemically positive for LV and elevated levels of islet autoantibodies. The finding of LV in the pancreatic islets of the diabetic bank voles raised the general question whether or not LV can participate in the development of diabetes in rodents as well as in humans.

In pilot experiments using human pancreatic specimens from nPOD, we have found faint immunostaining for LV in two autoantibody-positive patients using a rabbit anti Ljungan virus protein 1 (LV VP1) antibody. Other type 1 diabetic patients, as well as non-diabetic controls, stained negative for LV in the pancreas. Due to the weak intensity of the immunostaining, results are inconclusive and not further pursued at this time.