Prevalence of Scabies and Impetigo in School-Age Children in Timor-Leste

Abstract

Background Scabies and impetigo are endemic in many tropical, low- and middle-income countries. With control strategies emerging based on mass drug administration (MDA) with ivermectin, there is a need for comprehensive data on the occurrence and risk factors of these conditions to guide interventions and enable their impact to be assessed. In 2019, Timor-Leste Ministry of Health planned to implement MDA including ivermectin for the control of lymphatic filariasis, so we undertook a baseline assessment of scabies and impetigo. Methods A cross-sectional school survey was conducted in April-May 2019 at six primary schools in a semi-urban (Dili) and two rural (Ermera and Manufahi) settings. Children under 19 years of age present at school on survey days were eligible to participate, of whom we enrolled 1183. Trained health workers interviewed and examined 1043 participants to clinically diagnose scabies using the 2020 International Alliance for the Control of Scabies (IACS) diagnostic criteria, as well as impetigo. Prevalence was adjusted for age and sex. Mixed-effects logistic regression models were used to analyse odds of scabies and impetigo infection accounting for clustering at school level. Population attributable risk of scabies as a cause of impetigo was also estimated. Results The overall weighted prevalence of scabies was 30.6%. Children in rural Manufahi were more likely to have scabies than those in semi-urban Dili (53.6% vs 28.2%, adjusted odds ratio (AOR) 3.5). Most cases of scabies were mild (3 to 10 lesions), and distributed on more than one body region. Scabies prevalence was lower among 10 to 14 year olds compared to 5 to 9 year olds. Overall weighted prevalence of impetigo was 11.3%. Relative to Dili, children in rural Ermera and Manufahi were twice as likely to have impetigo. Impetigo was twice as common in children with scabies than in those without, corresponding to an attributable risk of scabies as a cause of impetigo of 22.7%. Conclusions Scabies and impetigo prevalence in Timor-Leste are among the highest reported globally, particularly in rural areas. Scabies infestation was strongly associated with impetigo. Comprehensive control strategies are urgently needed in Timor-Leste.