Molecular Detection and Epidemiology of Potentially Zoonotic <i>Cryptosporidium</i> spp. and <i>Giardia duodenalis</i> in Wild Boar (<i>Sus scrofa</i>) from Eastern Spain

The protozoans <i>Giardia duodenalis</i> and <i>Cryptosporidium</i> spp. are common causes of gastrointestinal disease in humans and animals. While both are commonly documented in domestic animals, few studies have analysed their presence in wildlife. To assess the prevalence of both parasites in wild boar (<i>Sus scrofa</i>) in the Valencian Community (eastern Spain), 498 wild boar faecal samples were collected from 2018 to 2022. <i>Cryptosporidium</i> spp. was detected by performing a nested PCR targeting a 578 bp sequence of the small subunit ribosomal RNA gene (SSU rRNA), followed by sequencing and phylogenetic analysis. For <i>G. duodenalis</i>, a qPCR amplifying a fragment of 62 bp from the SSU rRNA was employed. Positive samples were genotyped for glutamate dehydrogenase and β-giardin genes. Different epidemiological factors were considered potential modulating variables in the transmission of both parasites. <i>G. duodenalis</i> prevalence was 1.20%, while <i>Cryptosporidium</i> spp. prevalence reached 21.7%. Coinfection was observed in 0.2%. Genotyping of <i>G. duodenalis</i> isolates only detected genotype E. Two species of <i>Cryptosporidium</i> spp. were identified: <i>Cryptosporidium scrofarum</i> and <i>Cryptosporidium suis.</i> The results of this study demonstrate that the exposure to <i>Cryptosporidium</i> spp. in wild boars is high, particularly among young individuals belonging to the Typical Mediterranean climate. Moreover, the probability of infection is dependent on both the season and the density of wild boars. On the other side, exposure to G. duodenalis seems scarce and is influenced, in turn, by the climate. Both <i>Cryptosporidium</i> species detected in the present study have been reported in humans. Due to wild boar increasing in number and their colonisation of urban and peri-urban areas, this could represent an inherent health risk for the human population.