Detection of zoonotic protozoa in raccoons (Procyon lotor) from aquaculture zones in Saxony (Germany): One health perspective

The raccoon ( Procyon lotor ), an invasive species in Europe, is a potential reservoir for zoonotic pathogens, posing risks to human, animal, and environmental health. This study investigates the prevalence and genetic diversity of Giardia duodenalis and Cryptosporidium spp. in raccoons from the Upper Lusatian Heath and Pond Landscape (Saxony, Germany), adopting a One Health perspective at the wildlife–aquaculture interface. Fecal samples ( n = 104) were collected from culled raccoons (2020−2022) across six pond farming areas. Samples were screened using rapid immunochromatographic antigen tests, followed by molecular characterization via PCR and sequencing of specific loci ( gdh , tpi , and bg for Giardia ; SSU rRNA and gp60 for Cryptosporidium ). Giardia duodenalis assemblage B (sub-assemblage BIV) was detected in 24% of samples. Significant associations were observed with location ( p = 0.038) and aquaculture company ( p = 0.028). Cryptosporidium sp. skunk genotype was identified in 2% of samples, showing no significant correlation with the tested parameters. The identification of G. duodenalis (BIV) and Cryptosporidium skunk genotype highlights the role of raccoons as potential reservoirs in water-rich production landscapes. The high prevalence of Giardia and its spatial heterogeneity suggest that site-specific pond management and raccoon dynamics might influence pathogen loads. This study provides the first molecular evidence of zoonotic protozoa in raccoons within this specialized aquaculture context. The results underscore the necessity of integrating wildlife monitoring into aquaculture management. Aligning invasive species control with One Health surveillance is essential to mitigate zoonotic risks and safeguard public health in aquatic ecosystems.