Risk factors for Eimeria infections are well documented in farm and pet animals, but studies focusing on wildlife species are less common. This research aimed to investigate the impact of selected demographic and environmental factors on the prevalence of Eimeria in the European hare (Lepus europaeus). Additionally, we analysed whether Eimeria infection affected the behaviour of hares by examining the relationship between infection status and the likelihood of a hare being killed by a vehicle at a hotspot for road mortality. Between 11 February 2022 and 24 June 2024, we collected 22 hare carcasses that had been killed in traffic along an 83.9 km monitoring route in central Bohemia, Czech Republic, to evaluate Eimeria prevalence in relation to factors such as age, hare density, distance to the nearest water source and rainfall over the previous 3 months. Contrary to our expectations, we found a higher prevalence of Eimeria in adult hares compared to juveniles. We propose that this outcome may be due to the high mortality rates among leverets and juvenile hares, which removes susceptible individuals from the population early on. The effects of the other factors examined were not significant. In conclusion, our study revealed that Eimeria infection did not contribute to the clustering of hare–vehicle collisions. We emphasize the importance of studying risk factors in wildlife species across different ecological contexts. Our findings challenge the general assumption that age negatively influences Eimeria prevalence.

Accurate species identification is essential for biodiversity research, especially in the field of parasitological systematics. In particular, the incorporation of DNA-based methods in the study of Digenea has transformed taxonomy by allowing for precise species delimitation, clarification of life cycles, and the identification of cryptic diversity. However, to prevent taxonomic misidentification, a growing concern in public sequence databases, these molecular techniques must be supplemented with high-quality morphological data. This study provides an integrative assessment (combining both morphological and molecular data) of Cotylurus brandivitellatus, based on adult specimens obtained from naturally infected mute swan (Cygnus olor) in Gdańsk Pomerania. The observed morphological characteristics are consistent with the original description of C. brandivitellatus and align with the established description of the genus Cotylurus. Phylogenetic analysis, utilizing concatenated LSU rDNA and COI mtDNA markers, confirms the distinct taxonomic status of C. brandivitellatus. It forms a sister clade with C. strigeoides, which is clearly separate from other species within the Cotylurus genus. These findings validate the existence of C. brandivitellatus and offer new insights into species delineation and evolutionary relationships within Cotylurus, highlighting the importance of integrative approaches in trematode systematics.

Molecular analyses of geographically dispersed Fasciola spp. isolates based on ribosomal, mitochondrial and nuclear molecular markers have revealed high levels of genetic diversity within liver fluke populations. To investigate the Fasciola population substructure across Pakistan 4 molecular markers were compared (fatty acid binding protein, fabp; phosphoenolpyruvate carboxykinase, pepck; random amplified polymorphic DNA, RAPD; mitochondrial NADH dehydrogenase, mt-nd1). Adult parasites (n = 595) were collected from buffalo and cattle across 4 provinces in Pakistan (Baluchistan, Gilgit Baltistan, Khyber Pakhtunkhwa, Punjab). Species classification of all 595 parasites was confirmed by the 3 gel-based markers (pepck, fabp and RAPD) as F. gigantica, except for the fabp marker which unexpectedly could not be amplified in 274 parasites (46%). Analysis of a subset of samples indicates the potential for mis-priming due to multiple genomic loci that match the fabp primer sequences resulting in negative PCR products in some cases. Sequence analysis of the mt-nd1 PCR products identified 29 haplotypes within the samples from Pakistan, the majority of which are unique to this study. None of the 29 haplotype sequences were identified in samples from Africa, highlighting the genetic diversity between geographically disparate liver fluke populations. Inconsistencies between Fasciola spp. molecular markers in this study highlights the need for multiple markers, validated on large numbers of geographically disparate parasites, to generate robust analyses of liver fluke genetic diversity. This study echoes other Fasciola spp. population studies and highlights the genetic diversity of F. gigantica populations in Pakistan that is comparable to observations of diversity throughout Asia.

We analysed the early results of a screening and management protocol of imported female genital schistosomiasis (FGS) among migrant women from endemic countries. In total we screened 136 women, from which 39 had suspicion of FGS (serology-positive test and clinical signs and symptoms compatible). Median age was of 42.7 years [interquartile range (IQR 35–45)], median time living in the Europe (EU) was of 14 years (IQR 10–19) and all of them were coming from a West African country, mainly Senegal (17 out of 39; 43.6%). All of them had 1 or more clinical genitourinary findings [median 5 (IQR 2–6)], being the most prevalent pelvic pain, vaginal discharge and menstrual disorders. According to the protocol, colposcopy and cytology examination was performed in 11 participants, from whom 7 had findings compatible with FGS and 5 had low-grade cervical dysplasia with human papillomavirus (HPV)-negative results. After specific treatment with praziquantel (PZQ), we observed a high rate of resolution of clinical signs and symptoms, serology clearance at the 12th month of follow-up. Colposcopy lesions of 3 women assessed at the end of follow-up were fully resolved. Our findings and previous research support the implementation of management protocols of FGS in non-endemic countries, in spite of the knowledge gaps that still remain. Clinical trials need further assessment to determine the efficacy of PZQ, new diagnostic tools and the interaction between FGS, HPV and cervical cancer.

Strongyloides stercoralis has historically dominated research and control efforts for strongyloidiasis in both medical and veterinary fields. This has obscured the significance of other Strongyloides species infecting humans and their closest companions, dogs (Canis lupus familiaris) and cats (Felis catus). This review synthesized clinical and epidemiologic evidence on these neglected agents of human and companion animal strongyloidiasis and outlined priorities for future research. Our aim is to raise awareness of these understudied species and promote research to clarify their medical and veterinary public health significance. Targeted species-specific surveillance using molecular-genomic and advanced morphological tools is essential to uncover the true burden of these infections and inform strategies for their control and eventual elimination.

Acanthocephalans, which are in the family Polymorphidae, are a globally distributed group of endoparasites whose adults reside in the intestines of fish-eating birds, waterfowl and marine mammals. Adults of Polymorphus brevis and Pseudocorynosoma constrictum are endoparasites of fish-eating birds (Ardeids) and waterfowl (Anatidae), respectively, and are considered one of the most abundant and widely distributed species of polymorphids in freshwater systems from the Nearctic and Neotropical regions of Mexico and the USA. In the present study, sequences of cytochrome c oxidase subunit 1 (cox1) from mitochondrial DNA were generated from 67 specimens of P. brevis and 32 of Ps. constrictum from 12 localities on 6 biogeographic provinces in Mexico (the Trans-Mexican Volcanic Belt, Pacific Lowlands, Veracruzan, Californian, Sierra Madre Occidental, and Sonoran), plus the Temperate Prairies biogeographical province in the USA. The phylogeographic analyses indicated that the populations of both species lacked phylogeographic structure and exhibited high haplotype diversity, low nucleotide diversity and low Fst values among the biogeographic provinces; in combination with negative values in the neutrality test, these findings suggest that the populations of both species of acanthocephalan are undergoing expansion. The current evidence indicates that the biology of the definitive hosts, in combination with their migration patterns, could play a key role in shaping the distribution of haplotypes and the population genetic structure of the studied 2 acanthocephalan species.

Coccidiosis, caused by Eimeria spp., leads to substantial economic losses in the poultry industry globally. These protozoan parasites invade the intestinal epithelium of birds, impairing nutrient absorption, causing diarrhoea and potentially leading to mortality. The complex endogenous life cycle of Eimeria spp., particularly the gametogony phase, presents significant challenges for in vitro cultivation. This study aimed to develop mature chicken intestinal organoids as an in vitro model capable of supporting the complete endogenous life cycle of Eimeria tenella. Two commercially available culture media, 3dGRO L-WRN conditioned medium (L-WRN) and IntestiCult™ Organoid Growth Medium (OGM), were evaluated for their ability to support chicken intestinal organoid development. The results demonstrated that basolateral-out organoids embedded in Matrigel and cultured in the L-WRN medium expanded more rapidly. In contrast, those apical-out organoids in the OGM developed more microvilli structures on enterocytes. Apical-out organoids, initially cultured in L-WRN medium and subsequently matured in OGM, were selected as the optimal host for the Eimeria infection model. Sporozoites of E. tenella successfully invaded the organoids and progressed through both the schizogony and gametogony phases. Moreover, the parasites produced a new generation of oocysts in this study. The presence of schizonts, gametocytes, and sporulated oocysts confirmed that the model can support the full endogenous life cycle of the parasite in vitro. This organoid-based infection model serves as a promising platform for studying host–pathogen interactions and developing novel interventions to control avian coccidiosis.