Current views on ljungan virus and its relationship to human diabetes

The Ljungan virus (LV), a member of the Parechovirus genus and Picornaviridae family was isolated originally from its wild reservoir, the bank vole ( Myodes glareolus ) at the Ljungan River in central Sweden [Niklasson et al., 1999]. LV is associated with diseases such as myocarditis, encephalitis, pregnancy related diseases, and diabetes in several species of wild rodent [Niklasson et al., 2006a]. The same outcomes can be induced in mice under controlled laboratory conditions [Niklasson et al., 2006b]. Several mouse and rat animal models used to study diabetes have been found to carry LV naturally [Niklasson et al., 2007]. The role of the viruses in diabetes pathogenesis has been investigated by treating these animals with antiviral compounds [Holmberg et al., 2009]. Variation in the incidence of type 1 diabetes has been found to track the fluctuations in native rodent populations in central Sweden. Increased prevalence of antibodies to LV has been detected in Swedish type 1 diabetes cases. However, LV virus has not been isolated and its viral RNA has not been detected in type 1 diabetes. J. Med. Virol. 83:1673–1673, 2011. © 2011 Wiley‐Liss, Inc.