Scabies and Bacterial Superinfection among American Samoan Children, 2011-2012

Abstract

Background: Scabies, a highly pruritic and contagious mite infestation of the skin, is endemic among tropical regions and causes a substantial proportion of skin disease among lower-income countries. Delayed treatment can lead to bacterial superinfection, and treatment of close contacts is necessary to prevent reinfestation. We describe scabies incidence and superinfection among children in American Samoa (AS) to support scabies control recommendations.

Methodology/principal findings: We reviewed 2011-2012 pharmacy records from the only AS pharmacy to identify children aged ≤14 years with filled prescriptions for permethrin, the only scabicide available in AS. Medical records of identified children were reviewed for physician-diagnosed scabies during January 1, 2011-December 31, 2012. We calculated scabies incidence, bacterial superinfection prevalence, and reinfestation prevalence during 14-365 days after first diagnosis. We used log binomial regression to calculate incidence ratios for scabies by age, sex, and county. Medical record review identified 1,139 children with scabies (incidence 29.3/1,000 children aged ≤14 years); 604 (53%) had a bacterial superinfection. Of 613 children who received a scabies diagnosis during 2011, 94 (15.3%) had one or more reinfestation. Scabies incidence varied significantly among the nine counties (range 14.8-48.9/1,000 children). Children aged <1 year had the highest incidence (99.9/1,000 children). Children aged 0-4 years were 4.9 times more likely and those aged 5-9 years were 2.2 times more likely to have received a scabies diagnosis than children aged 10-14 years.

Conclusions/significance: Scabies and its sequelae cause substantial morbidity among AS children. Bacterial superinfection prevalence and frequent reinfestations highlight the importance of diagnosing scabies and early treatment of patients and close contacts. Investigating why certain AS counties have a lower scabies incidence might help guide recommendations for improving scabies control among counties with a higher incidence. We recommend interventions targeting infants and young children who have frequent close family contact.

Fig 1. Average annual pediatric scabies incidence by county, American Samoa.

Fig 2. Scabies incidence by month among American Samoan children aged ≤14 years.