Incidence of Kawasaki disease in northern European countries.

Background: The aim of the present study was to compare the epidemiologic features of Kawasaki disease (KD) in three northern European countries and Japan.

Methods: Data were obtained from discharge databases for hospitals in Finland, Norway, and Sweden for 1999-2009 and from nationwide epidemiologic surveys in Japan for 1998-2008. Annual incidence for each country was calculated using regional census data.

Results: During the 11 year period, 1390 KD patients were recorded in the registries of the three northern European countries. Average annual incidence rates per 100,000 children aged <5 years were: Finland, 11.4; Norway, 5.4; and Sweden, 7.4. Overall, 86.4% of Japanese KD patients were aged <5 years compared to only 67.8% in the four northern European countries (P < 0.001).

Conclusions: The incidence of KD in northern Europe was constant over the study period and much lower than in Japan. There was a significant age difference between northern European and Japanese KD patients that remains unexplained.