Background
Acute rheumatic fever (ARF) has diverse presentations and treatments. Children diagnosed with ARF need real-world information on what to expect including length of hospitalisation and likelihood of rheumatic heart disease (RHD). We aimed to describe ARF in Australia and New Zealand to answer clinical questions and determine practice differences.
Methods
We analysed clinical data from a multi-site, prospective cohort study ('Searching for a Technology-Driven Acute Rheumatic Fever Test', START) at Royal Darwin Hospital (Australia), Middlemore Hospital, and Starship Children’s Hospital (New Zealand). Patients hospitalised with confirmed ARF, 2018-2021, were eligible. We used descriptive analyses to compare sites and regression analysis to explore associations with length-of-stay.
Findings
We enrolled 143 episodes of ARF among 141 participants, median age 10 years (range 5-23). The commonest ‘phenotype’ was carditis, polyarthritis, fever, and PR prolongation. 61% had carditis. ARF recurrences, RHD, possible/probable ARF and underweight were more commonly diagnosed in Australia. Positive throat Group A Streptococcus culture was more common in New Zealand. Median length-of-stay was 7 days (range 2-66). Factors associated with longer hospitalisation (univariable model) were valve pathology, corticosteroid requirement, enrolment at Starship Children’s Hospital (cardiosurgical quaternary hospital), definite ARF, symptom duration, and higher inflammatory markers. Significant predictors for length-of-stay in the multivariable model were valve disease, corticosteroids, and higher ESR.
Interpretation
This study provides new knowledge on ARF management and highlights international variation in practice. Differing approaches need to be aligned. Meanwhile, locally-specific information can help guide patient expectations after ARF diagnosis.