Incidence of acute rheumatic fever in New Zealand children and youth

Aim: To estimate acute rheumatic fever (ARF) incidence rates for New Zealand children and youth by ethnicity, socioeconomic deprivation and region. Methods: National hospital admissions with a principal diagnosis of ARF (ICD9_AM 390-392; ICD10-AM I00-I02) were obtained from routine statistics and stratified by age, ethnicity, socioeconomic deprivation index (NZDep2006) and District Health Board (DHB). Results: The mean incidence rate for ARF in 2000–2009 peaked at 9 to 12 years of age. Incidence rates for children 5 to 14 years of age for Māori were 40.2 (95% confidence interval 36.8, 43.8), Pacific 81.2 (73.4, 89.6), non-Māori/Pacific 2.1 (1.6, 2.6) and all children 17.2 (16.1, 18.3) per 100 000. Māori and Pacific incidence rates increased by 79% and 73% in 1993–2009, while non-Māori/Pacific rates declined by 71%. Overall rates increased by 59%. In 2000–2009, Māori and Pacific children comprised 30% of children 5–14 years of age but accounted for 95% of new cases. Almost 90% of index cases of ARF were in the highest five deciles of socioeconomic deprivation and 70% were in the most deprived quintile. A child living in the most deprived decile has about one in 150 risk of being admitted to the hospital for ARF by 15 years of age. Ten DHBs containing 76% of the population 5 to 14 years of age accounted for 94% of index cases of ARF. Conclusions: ARF with its attendant rheumatic heart disease is an increasing public health issue for disadvantaged North Island communities with high concentrations of Māori and/or Pacific families.