Characteristics and Validity of a Web-Based Kawasaki Disease Surveillance System in Japan

Background: Although regular nationwide surveys of Kawasaki disease (KD) are conducted in Japan, there is no system for detecting the real-time epidemic status of this disease. Methods: A web-based surveillance system for KD was developed. After consideration of the number of patients reported by prefecture to the 19th nationwide survey, 355 pediatric departments were asked to participate in the surveillance, and 225 agreed. Since January 2008, pediatricians in these 225 hospitals have reported ED patient data immediately after diagnosis. The daily numbers of patients are available to the public via the internet at http://www.kawasaki-disease.net/kawasakidata/. The validity of the data in 2008 was evaluated using the Japanese 20th nationwide survey of KD as the gold standard. Results: A total of 3376 patients were reported to the web-based surveillance system from the 1st week through 52nd week of 2008. The number of patients reported to the nationwide survey during the same period was 11 680: a total of 4950 patients from the hospitals participating in the web-based surveillance and 6730 from other hospitals. The epidemic curves were similar, and the correlation coefficient between the web-based surveillance and the total numbers in the nationwide survey was 0.806 (P < 0.01). Conclusions: The web-based surveillance system for Kawasaki disease in Japan demonstrated good validity.