Kawasaki disease in New Zealand

AIM: To determine the epidemiology, management and outcome of Kawasaki disease (KD) in New Zealand. DESIGN: Prospective audit using New Zealand Paediatric Surveillance Unit (NZPSU) Reports. SETTING: Single country 2-year epidemiological study. Patients: All patients diagnosed with KD in New Zealand reported to the NZPSU from January 2001 to December 2002. MAIN OUTCOME MEASURES: Incidence of KD; time to diagnosis; use of intravenous immunoglobulin; cardiac features and outcome. RESULTS: Forty-nine new cases were identified. The annual incidence was 8.0 cases/100,000 children aged less than 5 years. Age at onset was less than 5 years in 86% of cases. Incidence was 4.6/100,000 for children of European origin, 9.6 for Maori, 12.2 for Pacific Islanders and 32.2 for children of East Asian origin. KD was diagnosed at a median of 6 days from onset of illness. 89% had fever and four or more diagnostic features. All patients had at least one echocardiogram: There was one small (2%) coronary artery aneurysm only; 13 (26%) had mild coronary artery dilatation. Thirty-five per cent did not have an echocardiogram performed four or more weeks from illness onset. 45 (92%) cases received intravenous immunoglobulin at median day six. There was one death due to occlusive coronary artery disease in a 3-month-old boy with atypical symptoms in whom KD was diagnosed at post-mortem. CONCLUSIONS: The incidence of KD in New Zealand is defined with significantly variable risk according to ethnicity. Most patients received appropriate rapid diagnosis and treatment but there was considerable variation in practice in regard to number and timing of echocardiograms. There was a low coronary artery aneurysm rate (2%). Accelerated vaso-occlusive disease was responsible for the single fatality in an atypical case.