Clinical Report: Epidemiology and Contributing Factors of Scabies in Africa

Overview

This systematic review and meta-analysis summarized available evidence on the prevalence of scabies and associated risk factors among children and adolescents in Africa.

Background

Scabies is a neglected tropical disease that affects approximately 204 million people worldwide and disproportionately affects resource-scarce tropical settings. Children and adolescents are particularly vulnerable because they are more likely to be infested and to experience severe complications from secondary bacterial infections.

Data Highlights

• The review included 35 studies with 45,425 participants.

• The pooled prevalence of scabies was 5.7% (95% CI, 3.6%-8.2%) across all included studies and 9.4% (95% CI, 6.5%-12.8%) among studies focused specifically on scabies.

• Prevalence was significantly higher in community-based studies than in school-based studies (12.8% vs 4.2%; P = 0.002).

Key Findings

• Scabies prevalence varied widely across studies, ranging from 0.03% to 27.3%.

• Pooled prevalence was highest in Eastern Africa at 7.4% and lowest in Central Africa at 3.2%, although differences between regions were not statistically significant.

• Factors associated with increased scabies risk included a family size of 5 or more, rural residence, lack of detergent for bathing or washing clothes, sleeping on the floor, sharing bedding or clothes, and contact with a scabies case.

• Scabies can cause substantial morbidity through intense pruritus, sleep disruption, social stigma, and secondary bacterial skin infections.

• Prevalence estimates varied according to study setting and diagnostic approach, and substantial heterogeneity was present across studies.

Clinical Implications

The findings indicate a substantial burden of scabies among children and adolescents in parts of Africa and identify several associated factors linked to poverty and living conditions. The authors emphasize the importance of improving living conditions, targeting interventions toward impoverished and rural communities, and using standardized diagnostic criteria in future epidemiological studies.

Conclusion

The review found high scabies prevalence in some parts of Africa, with substantial variation according to geographic region, study setting, population characteristics, and methods of case ascertainment. Poverty-related factors, including large household size, rural residence, inadequate personal hygiene, sleeping on the floor, and clothing sharing, were important associated factors. Future African studies using standardized International Alliance for the Control of Scabies diagnostic criteria are needed to guide research and public health strategies.

Related Resources & Content

1. World Health Organization. Scabies. WHO. Accessed September 18, 2022. https://www.who.int/news-room/fact-sheets/detail/scabies.

2. Karimkhani C, Colombara DV, Drucker AM, Norton SA, Hay R, Engelman D, et al. The global burden of scabies: a cross-sectional analysis from the Global Burden of Disease Study 2015. Lancet Infect Dis. 2017;17:1247-1254. doi:10.1016/S1473-3099(17)30483-8.

3. Hay RJ, Steer AC, Engelman D, Walton S. Scabies in the developing world—its prevalence, complications, and management. Clin Microbiol Infect. 2012;18:313-323. doi:10.1111/j.1469-0691.2012.03798.x.

4. Thomas C, Coates SJ, Engelman D, Chosidow O, Chang AY. Ectoparasites: scabies. J Am Acad Dermatol. 2020;82:533-548. doi:10.1016/j.jaad.2019.05.109.

5. Engelman D, Marks M, Steer AC, Beshah A, Biswas G, Chosidow O, et al. A framework for scabies control. PLoS Negl Trop Dis. 2021;15:e0009661. doi:10.1371/journal.pntd.0009661.

6. Kouotou EA, Nansseu JR, Kouawa MK, Zoung-Kanyi Bissek AC. Prevalence and drivers of human scabies among children and adolescents living and studying in Cameroonian boarding schools. Parasit Vectors. 2016;9:400. doi:10.1186/s13071-016-1690-3.