Detecting spatial clusters of human scabies in Tigray, Ethiopia from 2018 to 2023.

Background: Scabies is one of public health concerns among communicable disease in Ethiopia, especially among disadvantaged and the poor. This current study aims to detect the spatiotemporal patterns of scabies in Tigray from 2018 to 2023 using scabies data aggregated at the zonal level. The study also examined the persistent patterns in the spatial variation of scabies incidence across the administrative regions during the study period.

Method: We collected scabies data using a weekly disease surveillance reporting format of the country from 2018 to 2023 across all accessible district health facilities in Tigray region, Ethiopia. We conducted retrospective analyses using both purely spatial and spatiotemporal scan statistic approaches, employing a discrete Poisson probability model to identify statistically significant clusters of high scabies rates throughout the Tigray regional zones in Ethiopia. Our methodology involved the use of Kulldorff's spatial scan statistic software (SaTScan v10.1.3), R programming software version 4.3.1, and ArcGIS Pro for all analyses.

Results: A total of 101,116 cases of scabies were reported from 2018 to 2023. Our study indicated a spatial heterogeneity in the pattern of scabies across Tigray region as well as its localization among geographically contiguous zones across space, except for the Western zone of Tigray where no data was collected. The detected statistically significant spatial clusters [Formula: see text] persisted mainly in the Central, Eastern and Northwestern zones of Tigray over the six years of the study period. The highest relative risk (RR) was recorded in year 2021 ([Formula: see text]. The central zone had the major clusters of scabies at district level from 2018 to 2023. The heterogeneous distribution of scabies across Tigray could be due to the spatial variations in the determinants of scabies (such as socioeconomic status, demographics, and material deprivation) across the region.

Conclusion: An enormous burden of scabies was reported over a period of six years. The present study found localized clusters of high scabies rates at district and zonal levels in Tigray, Ethiopia, possibly due to differences in various determinants of scabies such as access to WASH services. The findings could help the government and health authorities to develop and implement scabies control strategies in Tigray, with a focus on high-risk districts and zones to ensure optimal resource allocation.