currently, the incidence of initial episodes of ARF is 4.2 cases per 100,000 population per year (equaliting to 187 new cases in 2011), 70 percent of which occur in children aged five to 14 years. However,recently published data shows that in Northland between 2002 and 2011, the annual incidence of ARF was 7.7 cases per 100,000.