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

TL;DR

This study found high prevalence of certain gut protozoa in pigs raised for human consumption in Portugal and Spain, raising concerns about worker exposure risks.

Contribution

The study provides new data on the prevalence of zoonotic protozoa in pigs from the Iberian Peninsula, including regional differences and variant-specific findings.

Findings

Balantioides coli was highly prevalent in pigs from both Portugal and Spain, with variant B predominating.

Cryptosporidium scrofarum was detected only in Portuguese pigs, while Giardia duodenalis was more common in Portugal.

The findings highlight the need for biosecurity measures to reduce occupational exposure risks in pig farming and slaughterhouse environments.

Abstract

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.

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