The Prevalence of Scabies, Skin Infection and Rheumatic Heart Disease in a Cross-Sectional Study of Tongan Primary School Children

Background

Scabies is a common health issue in the Pacific and may contribute to rheumatic heart disease (RHD). This study assessed the prevalence of scabies and other skin conditions among Tongan schoolchildren and examined the association between these conditions and RHD.

Methods

Children from four primary schools on Tongatapu were screened for scabies, other skin conditions and RHD. Health workers were trained to recognise scabies and related skin conditions accurately. All children also underwent echocardiographic screening to detect heart valve abnormalities consistent with RHD. Statistical analysis included prevalence ratio calculations, and Fisher's exact tests to evaluate associations between skin and heart findings.

Results

Four hundred children were screened (mean age: 8 years 6 months), with 18 (4.5%) having echocardiographic features of RHD. The prevalence of scabies was 29.8% (119/400), while the prevalence of impetigo was 20% and more severe bacterial skin infection was 15.5%. Children with both scabies and skin infection were 4.65 times more likely than children without any such lesions to have RHD (95% confidence interval: 1.60–13.6). Children with scabies, impetigo and bacterial infection were associated with progressively higher prevalence of RHD (p for trend = 0.008). The population attributable fraction for scabies and infection as a potential cause of RHD was 26.5%.

Conclusions

The results indicate a very high prevalence of scabies, bacterial skin infection, and RHD among Tongan school children. Enhanced treatment and control of scabies are likely to reduce the incidence of both bacterial infection and RHD. Mass drug administration is recommended.