Scabies is strongly associated with acute rheumatic fever in a cohort study of Auckland children

Abstract

Aim: This study sought to determine whether scabies infection is associated with acute rheumatic fever (ARF) or chronic rheumatic heart disease (CRHD).

Methods: A cohort study was undertaken using health records of children aged 3-12 years attending an oral health service for the first time. Subjects were then linked to hospital diagnoses of scabies and ARF or CRHD.

Results: A total of 213 957 children free of rheumatic heart disease at baseline were available for analysis. During a mean follow-up time of 5.1 years, 440 children were diagnosed with ARF or CRHD in hospital records. Children diagnosed with scabies during follow-up were 23 times more likely to develop ARF or CRHD, compared with children who had no scabies diagnosis. After adjustment for confounders in a Cox model, the association reduced but remained strong (adjusted hazard ratio: 8.98; 95% confidence interval: 6.33-20.2). In an analysis restricted to children hospitalised at least once during follow-up, the adjusted hazard ratio for the same comparison was 3.43 (95% confidence interval: 1.85-6.37).

Conclusions: A recent diagnosis of scabies from hospital records is strongly associated with a subsequent diagnosis of ARF. Further investigation of the role that scabies infestation may play in the aetiology of ARF is warranted.

Keywords: cohort studies; epidemiology; rheumatic fever; scabies.