Silent shedding of zoonotic enteric protozoa in domestic pigs for human consumption in selected farms in the Iberian Peninsula

Enteric protozoa such as Balantioides coli, Giardia duodenalis, and Cryptosporidium scrofarum are of veterinary importance and may pose occupational exposure risks, yet data on their occurrence in pigs (Sus scrofa domesticus) raised for human consumption in the Iberian Peninsula are limited. A total of 400 stool samples were collected at a slaughterhouse in northern Portugal, originating from farms in Portugal (n = 200) and Spain (n = 200), and screened by PCR and qPCR. B. coli was highly prevalent in both countries (Portugal: 93%, Spain: 89.5%), with variant B predominating and variant A detected only in Portugal. C. scrofarum was detected exclusively in Portuguese pigs (4.5%), whereas G. duodenalis occurred more frequently in Portugal (8.5%) than in Spain (0.5%). These findings indicate that enteric protozoa of veterinary and potential occupational relevance are widespread in Iberian pig production, highlighting the importance of biosecurity measures for workers in contact with pigs and slaughterhouse environments.