Rising scabies incidence in Spain: a retrospective observational analysis of four national data sources, 2011 to 2023

BACKGROUNDScabies is a skin disease caused by the mite Sarcoptes scabiei, resulting in intense itching and rash, and sometimes secondary infections with complications. Scabies is not typically a notifiable disease, which makes estimating its burden of disease challenging. In recent years, sharp increases have been reported in Europe.AIMThis study characterises scabies epidemiology in Spain from 2011 to 2023.METHODSThis retrospective study triangulated data from primary care, hospital admissions, occupational diagnoses and outbreaks. Annual incidence rates (IRs) were calculated to assess temporal evolution, demographics and geographic distribution. Joinpoint regression identified IR changes, and time-series analysis explored seasonality. Occupational and outbreak data analysis identified high-risk activities and settings.RESULTSIncidence rates increased across all data sources, with marked acceleration from 2020-21. The greatest rise was seen in primary care (annual percentage change rose from 22.8% (95% CI: 7.2-31.9) in 2011-20 to 65.8% (95% CI: 47.5-96.6) in 2020-23). The IR was highest amongst 15-24-year-olds. Hospitalisations, with highest IR among people > 65 years, peaked each January. Occupational diagnoses were predominantly registered in healthcare settings (82.0%). Islands and northern coastal regions were most affected. Outbreaks were most frequent in households and nursing homes, with largest outbreaks in healthcare settings.CONCLUSIONSGiven the increasing incidence of scabies in Spain, a strong response is needed to improve prevention, diagnosis, and treatment. Improved surveillance and targeted public health initiatives could mitigate further spread, as well as further research to better elucidate the mite-related and epidemiological factors that underline the recent increases across Europe.