BACKGROUND: Robust evidence is lacking for community initiatives to prevent first presentation acute rheumatic fever (ARF) by group A streptococcal (GAS) pharyngitis treatment. Significant NZ government investment centred on school clinics.
METHODS: We measured the effect of introducing a sore throat clinic program on first presentation ARF into 61 year 1-8 schools with students aged 5-13years ( population ~ 25 000 ). in Auckland, NZ. The study period was 2010-2016. A generalised linear mixed model investigated ARF rate changes before and after the staggered introduction of school clinics. Nurses/ lay workers treated culture-proven GAS sore throats (including siblings) with 10 days amoxicillin. ARF cases were identified from a population-based secondary prophylaxis register. Annual pharyngeal GAS prevalence was assessed in a subset.
RESULTS: ARF rates (5-13 years) dropped from 88 (95% CI 79, 111)/100,000 pre clinics to 37 (95% CI 15, 83)/100,000 after 2 years of clinics, a 58% reduction.
No change in rate was demonstrated prior to the introduction of clinics (p=0.88, incidence risk ratio (IRR) for a one year change 0.98 (95% CI 0.63, 1.52)) but there was a significant decrease of first presentation ARF rates over time following the introduction of the sore throat program (p=0.008, IRR 0.61 (95% CI 0.43, 0.88)).
Pharyngeal GAS cross sectional prevalence fell from 22.4% (16.5, 30.5) pre intervention to 11.9% (8.6, 16.5) and 11.4% (8.2, 15.7) one and two years later (p=0.005)
CONCLUSIONS: ARF declined significantly following school-based GAS pharyngitis management using oral amoxicillin paralleled by a decline in pharyngeal GAS prevalence.