Prevalence of scabies and bacterial skin infection in French Polynesia: A cross-sectional community survey

TL;DR

This study found high rates of scabies and bacterial skin infections in French Polynesia, especially in young children, suggesting the need for community-wide treatments.

Contribution

The study provides the first formal prevalence data on scabies and bacterial skin infections in French Polynesia.

Findings

Scabies prevalence was 11.9%, exceeding the 10% threshold for mass drug administration.

Children under 5 years had the highest scabies prevalence at 31.8%.

Scabies was associated with a 10-fold higher risk of bacterial skin infection.

Abstract

The prevalence of scabies and impetigo is high in several Pacific Island countries and has led to the implementation of mass drug administration control strategies. Anecdotal clinical reports have suggested similarly high burdens of scabies and bacterial skin infection in French Polynesia, but formal prevalence data have been lacking. We aimed to determine the prevalence of scabies and bacterial skin infection in French Polynesia’s two most populated islands: Tahiti and Mo’orea.

We conducted a community-based cross-sectional survey. Our study was pragmatically restricted to the main islands of Tahiti and Mo’orea, where we selected households using two-stage randomisation from 20 first-stage neighbourhoods. All individuals present in the home were invited to participate. Four nurses and one doctor conducted skin examinations using validated simplified diagnostic criteria to diagnose scabies, informed by the International Alliance for the Control of Scabies 2020 diagnostic criteria.

Among 1770 participants, scabies prevalence was 11.9% and was highest among children aged <5 years (31.8%, RR 5.7, 95% CI 3.8 – 8.6, compared to ≥55 years). The overall bacterial skin infection prevalence was 5.5%. Participants with scabies had a 10-fold higher risk of bacterial skin infection compared to those without (26.8% vs 2.7%, RR 10.2, 95% CI 7.5–13.8). Written consent was obtained for all 1770 participants.

The prevalence of scabies in this study exceeds 10%, the threshold above which evidence-based public health strategies including mass drug administration (treatment of the entire community, regardless of whether they show evidence of the disease) may be considered.

Scabies is a skin infestation due to the mite Sarcoptes scabei var homini which causes intense itch, negative impact on quality of life, and commonly leads to secondary bacterial skin infections and their sequelae. Anecdotal reports suggest high burdens of scabies and bacterial skin infection in French Polynesia, but prevalence data have been missing. We aimed to quantify the prevalence of these skin diseases in the main islands of Tahiti and Mo’orea. In a cross-sectional survey, we used validated simplified diagnostic criteria to diagnose scabies, and found that 11.9% of 1770 participants had scabies, and 5.5% had bacterial skin infection, which is comparable to rates found in other Pacific contexts. Participants with scabies were ten times more likely to have bacterial skin infection, and children carried the highest burden of both diseases. These results support the need for community-wide public health interventions to reduce the prevalence of scabies, such as through mass drug administration.

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