Ten years of routine molecular detection of Cyclospora cayetanensis in northern Spain: diagnostic and epidemiological insights from a non-endemic setting.

Cyclospora cayetanensis is an emerging cause of prolonged diarrhoea that remains underdiagnosed in Europe because routine laboratory testing is uncommon and conventional diagnostic methods have limited sensitivity. We retrospectively reviewed laboratory-confirmed cases of cyclosporiasis diagnosed following the implementation of routine multiplex GI PCR panel at a tertiary-care hospital in northern Spain between 2016 and 2025. Among 97,116 stool specimens screened, 52 infections were identified. Most patients had recently travelled to endemic regions, predominantly Mexico, whereas nine had no recent travel history. One of these patients reported habitual consumption of imported food, although exposure during the relevant period could not be established. Routine multiplex PCR improves the detection of cyclosporiasis in non-endemic settings and enables the identification of infections beyond the classical travel-associated pattern, supporting the inclusion of C. cayetanensis in routine gastrointestinal molecular diagnostic panels, not only for travel-associated diarrhoea but also for sporadic infections without recent travel.