Relationship between the incidence of type 1 diabetes and enterovirus infections in different European populations: results from the EPIVIR project.

The incidence of type 1 diabetes varies markedly between countries. As enterovirus infections have been linked to type 1 diabetes, we determined whether this variation correlates with the frequency of enterovirus infections in different Caucasian populations in Europe. Enterovirus antibodies were examined in the background population (1-year-old and 10-14-year-old children) in seven countries with either exceptionally high (Finland and Sweden) or low/intermediate incidence of diabetes (Estonia, Germany, Hungary, Lithuania, Russia) using EIA and neutralisation assays. Enterovirus antibodies were less frequent in countries with high diabetes incidence compared to countries with low diabetes incidence (P<0.001). This suggests that enterovirus infections are not particularly common in countries with high diabetes incidence. In contrast, there seems to be an inverse correlation between the incidence of type 1 diabetes and enterovirus infections in the background population, which is in line with the previously proposed polio hypothesis according to which the complications of enterovirus infections become more common in an environment with a decreased rate of infections.