BackgroundAlthough the number of patients and incidence rate of Kawasaki disease (KD) are increasing in Japan, the most recent epidemiologic features of KD are not known.MethodsThe 21st nationwide survey of KD was conducted in 2011 and included patients treated for the disease in 2009 and 2010. Hospitals specializing in pediatrics, and hospitals with a total of 100 or more beds and a pediatric department, were asked to report all patients with KD during the 2 survey years.ResultsA total of 1445 departments and hospitals reported 23 730 KD patients (10 975 in 2009 and 12 755 in 2010): 13 515 boys and 10 215 girls. The annual incidence rates were 206.2 and 239.6 per 100 000 children aged 0 to 4 years in 2009 and 2010, respectively; the 2010 rate was the highest ever reported in Japan. Monthly number of patients peaked during winter to spring months; lower peaks were noted during summer months. However, the seasonal patterns in 2009 and 2010 differed from those of previous years. The age-specific incidence rate had a monomodal distribution, with a peak during the latter half of the year of birth. The prevalences of cardiac lesions during acute KD and cardiac sequelae were higher among infants and older age groups. Despite a decrease in prevalence, the proportion of patients with giant coronary aneurysms—the most severe sequela of KD—did not substantially decrease.ConclusionsThe incidence rate and number of patients with KD continue to increase in Japan.

BackgroundThe number of patients and incidence rate of Kawasaki disease (KD) are increasing in Japan. We have therefore characterized the latest epidemiological information on KD.MethodsThe 22nd nationwide survey of KD, which targeted patients diagnosed with KD in 2011 and 2012, was conducted in 2013 and included a total of 1983 departments and hospitals. In order to report on all patients with KD during the 2 survey years, we targeted hospitals of 100 beds or more with pediatric departments, or specialized pediatric hospitals.ResultsFrom a total of 1420 hospitals and departments (71.6% response rate), 26 691 KD patients were reported (12 774 in 2011 and 13 917 in 2012; 15 442 males and 11 249 females). The annual incidence rates were 243.1 per 100 000 population aged 0 to 4 years in 2011 and 264.8 in 2012. The number of cases of KD recorded in 2012 was the highest ever reported in Japan. The incidence rate of complete cases was also the highest ever reported in Japan and contributed to the increase in the rate of total cases in recent years. The number of patients diagnosed per month peaked in January, and additional peaks were noted during summer months, although these peaks were lower than those seen in winter. Age-specific incidence rate showed a monomodal distribution with a peak in the latter half of the year in which patients were born.ConclusionsThe number of patients and the incidence rate of KD in Japan continue to increase. A similar trend has also been seen for patients with complete KD.

BackgroundCardiac lesions, such as coronary dilatation, aneurysms, narrowing, myocardial infarction, and valvular lesions, sometimes occur in Kawasaki disease, but most studies have only evaluated cardiac lesions in the later phase of the disease. This study was undertaken to clarify the related factors between cardiac lesions and laboratory data in the initial phase of Kawasaki disease.MethodsWe conducted a cross-sectional study using data for 26 691 patients from the 22nd nationwide survey of Kawasaki disease in Japan, the observation period of which was from January 2011 through December 2012. We excluded patients with recurrent Kawasaki disease and who were more than seven days from the start of symptoms at admission. We analyzed 23 155 cases (13 353 boys; mean age: 923 ± 734 days) with available laboratory data for white blood cell count, platelet count, serum albumin, and C-reactive protein (CRP).ResultsCardiac lesions were detected in 984 cases (656 boys and 328 girls); lesions were classified as coronary dilatation (764 cases), coronary aneurysm (40), giant coronary aneurysm (6), coronary narrowing (3), and valvular lesions (204). The significant related factors of initial coronary dilatation were male sex (odds ratio [OR] 1.73), older age (OR per 100 days increase 1.03), higher platelet count (OR per 10 000 cells/µL increase 1.006), lower albumin (OR per 1 g/dL increase 0.66), and higher CRP (OR per 1 mg/dL increase 1.02). The factors related to coronary aneurysm were higher platelet count (OR 1.01) and lower albumin (OR 0.34). No factors were significantly related to giant coronary aneurysm. The related factors of valvular lesions were age (OR 0.98), and higher CRP (OR 1.05).ConclusionsClinicians should consider male sex, older age, higher platelet count, lower albumin levels, and higher CRP levels when assessing risk of cardiac lesions in the initial phase of Kawasaki disease.

BackgroundThe long-term outcomes of Kawasaki disease (KD) are unknown.MethodsFifty-two collaborating hospitals collected data on all patients who had received a new definite diagnosis of KD between July 1982 and December 1992. Patients were followed until December 31, 2009 or death. Standardized mortality ratios (SMRs) were calculated based on Japanese vital statistics data.ResultsOf the 6576 patients enrolled, 46 (35 males and 11 females) died (SMR: 1.00; 95% CI: 0.73–1.34). Among persons without cardiac sequelae, SMRs were not high after the acute phase of KD (SMR: 0.65; 95% CI: 0.41–0.96). Among persons with cardiac sequelae, 13 males and 1 female died during the observation period (SMR: 1.86; 95% CI: 1.02–3.13).ConclusionsIn this cohort, the mortality rate among Japanese with cardiac sequelae due to KD was significantly higher than that of the general population. In contrast, the rates for males and females without sequelae were not elevated.

BackgroundThe prevalence of Internet addiction (IA) among employed adults has not been reported using a large sample. To clarify the actual status of addictive Internet use among employed adults, this study aimed to evaluate the prevalence and the risk factors of IA and at-risk IA among employed adults in Japan.MethodsThis cross-sectional study surveyed all junior and senior high school personnel in Shimane Prefecture, a rural area in Japan. Eligible participants included 3,211 junior and senior high school personnel (1,259 men and 1,952 women). Participants completed a questionnaire on their activities and factors related to Internet use.ResultsThe prevalence of IA and at-risk IA was 0.03% and 4.82%, respectively. Furthermore, game playing was shown to be the Internet activity most closely associated with at-risk IA.ConclusionsThis study showed that around 5% of school personnel in a rural area in Japan are at risk for developing addiction to the Internet and that using the Internet for game playing is related to at-risk IA. Our results suggest that employed adults should be instructed to use the Internet properly.