The prevalence of antibodies against viruses causing Kumlinge and Pogosta diseases on the islands of Iniö on the southwest coast of Finland.

The prevalence of antibodies against viruses causing Kumlinge (tick-borne encephalitis) and Pogosta disease in the population of Iniö, a small island community in southwest Finland was measured. Antibodies against Kumlinge disease were found in 28% of the population, and increased from 10% in the 0-19 year age group to 42% in the 60-79 year age group. The prevalence varied markedly between different islands, being highest in the outer, bushy islands. Antibodies against Pogosta disease were detected in 2.7%.