The Epidemiology and Clinical Features of Kawasaki Disease in Australia

Abstract

The current Australian epidemiology of Kawasaki disease (KD) is poorly defined. Previous enhanced surveillance (1993-1995) estimated an incidence of 3.7/100,000 <5 years. We identified all patients hospitalized in Western Australia (current population ∼2.4 million) 1979 through 2009 with a discharge diagnosis of KD. We reviewed demographic, clinical, laboratory, and echocardiographic data from individual patient files and derived age-specific population estimates. KD diagnosis was made using standard criteria. There were 353 KD cases, with incomplete KD in 34 (9.6%). Male to female ratio was 1.7:1 and median age was 3.8 years (interquartile range 12-60 months). Fifty (18.1%) patients were Asian. Mean annual incidence increased from 2.82 per 100,000 children aged <5 years (95% confidence interval, 1.93-3.99) in 1980 to 1989, to 7.96 (6.48-9.67) in 1990 to 1999, to 9.34 (7.72-11.20) in 2000 to 2009. The highest incidence was 15.7 in 2005. A total of 293 children (83%) received intravenous immunoglobulin and 331 (95.4%) aspirin. Of 282 children who completed echocardiographic studies, 47 (16.7%) had coronary artery (CA) ectasia/dilatation and 19 (6.8%) had CA aneurysms; male gender was significantly associated with CA abnormalities. KD epidemiology in Western Australia mirrors that of other industrialized, predominantly European-Caucasian populations. The rising incidence likely reflects both improved ascertainment and a real increase in disease burden. The current Australian incidence is threefold higher than previously reported and similar to the United Kingdom. The CA outcomes, which include the pre-intravenous immunoglobulin era, are comparable to those reported elsewhere.