Occurrence and Molecular Characterization of spp. in Swine Farms in Northeastern Spain.

spp. are protozoan parasites that cause cryptosporidiosis, an enteric disease that can affect a wide range of vertebrate hosts. Pigs play a potential role in the transmission of spp. to humans, although infections are most often subclinical. This study aimed to assess the occurrence and molecular characterization of spp. in swine farms located in Aragón, northeastern Spain. Fecal samples ( = 72) were collected from 10 breeding farms, encompassing various production stages (lactation, nursery, fattening, and/or wean-to-finish). Data regarding the type of production system (two- or three-stage), production stages, and farming facilities (the type of flooring and water source) associated with the parasite presence were also analyzed using a questionnaire. The results showed that spp. were more frequently detected in fecal samples originating from three-stage production systems (21.9%) compared to two-stage systems (12.5%). Samples from the fattening stage exhibited the highest positivity rate and estimated oocyst count (3.0 oocyst/microscopic field). Furthermore, the molecular characterization of spp. revealed the circulation of multiple species both among farms and within the same pig production flow, with being the most prevalent species (7/72; 9.7%), followed by (1/72; 1.4%). These findings underscore the importance of the surveillance and molecular characterization of spp. for controlling infections in pigs, considering the potential for the zoonotic transmission of this parasite to humans.