Four-Weekly Benzathine Penicillin G Provides Inadequate Protection against Acute Rheumatic Fever in Some Children

: This study aimed to identify recurrent acute rheumatic fever (ARF) episodes which occurred despite adherence to prophylactic benzathine penicillin G (BPG). Data from Australia's Northern Territory were analyzed; ARF recurrences between 2012 and 2017 diagnosed while the person was prescribed BPG were identified. Days at risk (DAR)-median and interquartile range-preceding ARF onset were calculated. The timing of BPG doses was examined for individuals with no DAR. One hundred sixty-nine ARF recurrences were analyzed; median DAR in the previous 8 weeks before ARF onset was 29. Most recurrences occurred following > 7 DAR (87%). Eight recurrences (5%) occurred despite no DAR; all were aged less than 16 years at the time of their recurrence/s. Recurrent ARF most commonly occurs after delayed BPG doses, but in some cases, receiving every prescribed BPG dose on time did not prevent recurrent ARF. A method to identify high-risk individuals before recurrent ARF is needed.