Parasitologia

The Atlantic chub mackerel, Scomber colias, is sold in Spain, as well as another species of the genus, like the Atlantic mackerel, S. scombrus, often mistaken to be the same fish. This study aims to analyse the risk of human anisakiosis through the consumption of S. colias, and to clarify if these two species differ regarding this risk. A total of 250 S. colias (125 originating from the Atlantic and 125 from the Mediterranean) were helminthologically analysed using conventional parasitological techniques. Concerning Ascaridoid nematodes, the prevalence of Anisakis type I was higher in the Atlantic than in the Mediterranean. The presence of three other helminth parasites stands out, two other Ascaridoid nematodes, the larvae of Contracaecum spp. and Hysterothylacium spp., the latter a food-spoiling and non-pathogenic parasite. The other helminth found was the intestinal adult of the acanthocephalan Rhadinorhynchus pristis, also non-pathogenic. The comparison of the current results with previously published ones by our research group on S. scombrus show that Anisakis type I prevalence was higher in S. scombrus than in S. colias, making the correct differentiation between them necessary, given their varying risk of human anisakiosis. Furthermore, fish label information is important to prevent the risk of anisakiosis for consumers. Full article

Plasmodium vivax malaria continues to pose a significant and enduring public health challenge across the Americas. Transmission-blocking vaccines (TBVs), which target gametocyte surface antigens such as Pvs47 and Pvs48/45, are being investigated as promising tools to interrupt transmission and advance toward disease elimination. To investigate the genetic diversity and phylogeographic structure of the pvs47 and pvs48/45 genes in P. vivax, we conducted molecular analyses on samples collected from seven malaria-endemic regions of Honduras using PCR-based sequencing, population genetics, and phylogenetic approaches. This study presents the first complete characterization of the pvs47 gene and expands the available data on pvs48/45 in P. vivax from Honduras. We observed a low level of genetic diversity with no evidence of geographic structuring within the country. At a global scale, Honduran sequences shared variants with other Latin American strains and exhibited region-specific amino acid signatures. These findings suggest that local selective pressures, possibly driven by mosquito vector compatibility, are shaping the evolution of these TBV candidate genes. Our results underscore the importance of regional surveillance to inform the development and deployment of effective transmission-blocking strategies. Full article

Intestinal microbial eukaryotic parasites represent a significant public and veterinary health burden, especially in low- and middle-income countries, yet their transmission dynamics at the human–animal–environment interface remain poorly characterized in certain countries. This study investigated the prevalence and genetic diversity of key microbial eukaryotes, including Cryptosporidium spp., Giardia duodenalis, Blastocystis spp., Entamoeba histolytica, and Enterocytozoon bieneusi, in a rural village in Iraq. Samples collected from humans (n = 50), livestock (sheep and goats, n = 50), water (n = 20), and soil (n = 20) were analysed using microscopy and molecular methods (qPCR and nested PCR). Blastocystis spp. (78% animals, 16% humans, 45% soil, 5% water) and Cryptosporidium spp. (26% animals, 12% humans, 5% soil, 15% water) were the most frequently found microeukaryotes using either microscopy and/or molecular detection. Molecular methods identified Cryptosporidium parvum in humans and sheep, hinting at zoonotic transmission potential. Enterocytozoon bieneusi and Giardia were also found. Cryptosporidium ubiquitum and E. bieneusi genotypes BEB6 and COS-I, respectively, were detected exclusively in sheep, suggesting roles as potential reservoirs. Blastocystis ST1 was detected in humans, while ST4 and ST10 occurred in sheep. Notably, molecular detection rates of Blastocystis were much lower than those of microscopy. Entamoeba histolytica was not detected. The detection of the same organisms in humans, animals and the environment suggest zoonotic and environmental transmission pathways, which warrant further investigation using the One Health approach. Full article

Fascioliasis, a parasitic disease caused by liver flukes of the genus Fasciola, remains a significant threat to livestock productivity globally. Despite its economic and zoonotic importance, the knowledge levels of dairy farm personnel regarding this disease remain insufficiently explored in South Africa. This study assessed knowledge and awareness of bovine fasciolosis, including its etiology, risk factors, clinical signs, zoonotic implications, and control measures, among dairy farm personnel in the Eastern Cape Province. A structured questionnaire was randomly administered to 152 dairy farm workers. Descriptive statistics and Chi-square tests were used to examine associations between respondents’ demographic characteristics and their knowledge of fasciolosis. Most respondents were males (65.8%), aged 31–40 years (45.4%), with tertiary education (64%), over six years of experience (65%), and residing in inland regions (65.4%). A high proportion reported implementing pasture management practices such as irrigation (90.8%), pasture resting (69.8%), and rotation (94.7). Significant associations were found between geographic location and knowledge of Fasciola spp. as the causative agent, as well as awareness of swampy areas and water snails as key risk factors (p < 0.01). Educational level was significantly associated with awareness of the zoonotic potential of fasciolosis (p < 0.01), and regional location influenced knowledge on control practices (p < 0.01). These findings highlight persistent gaps in the understanding of bovine fasciolosis among dairy farm personnel, particularly in relation to causative agents, clinical signs, and zoonotic risk. Strengthening extension services, enhancing community awareness, and implementing targeted training programs are essential to address these knowledge gaps and improve disease control strategies in the Eastern Cape Province. Full article

Seabirds of the families Fregatidae, Phalacrocoracidae and Sulidae, common on the southeastern coast of Brazil, form colonies and play a bioindicator role in coastal ecosystems due to their ecological habits. This study aimed to identify the prevalence of parasitic helminths in Suliformes birds, of the species Fregata magnificens Mathews, 1914, Sula leucogaster Boddaert, 1783 and Nannopterum um Gmelin, 1789, from the Instituto de Pesquisas Cananeia (IPeC) on the southern coast of the State of São Paulo, and to record the diversity and parasitic indices, since reports of helminth prevalence in pelagic birds are scarce in Brazil. From 2018 to 2020, a total of 270 nematode specimens and 271 acanthocephalan parasites were collected from 51 Suliformes birds (20 F. magnificens, 10 N. brasilianum and 21 S. leucogaster). The host species F. magnificens was parasitized by Contracaecum plagiaticium and Contracaecum pelagicum. The host S. leucogaster was parasitized by C. plagiaticium. In the host N. brasilianum, specimens of Contracaecum australe, Contracaecum rudolphii, Contracaecum multipapillatum, Syncuaria squamata and Andracantha tandemtesticulata were found. This is the first report of C. plagiaticium and C. pelagicum in F. magnificens in Brazilian territory, and of A. tandemtesticulata in N. brasilianum in the southeast region of Brazil. Full article

Microsporidia MB (MB), a promising biological control agent, suppresses Plasmodium falciparum transmission in Anopheles mosquitoes. This study examined the spatial distribution of MB infection in natural populations of An. gambiae s.l. mosquitoes collected in Nigeria and Niger Republic, and its association with insecticide susceptibility in the mosquitoes. Microsporidia MB has wide geographic distribution across Nigeria and Niger Republic. The overall prevalence of MB in F₀ mosquitoes was 12.25% (95% CI: 7.76–16.75%); 25 mosquitoes out of 204 were positive. Geographic variation was observed, with a higher prevalence (5/15 mosquitoes) in Ebonyi State (33.33%, CI: 9.48–57.19%, Fisher’s exact test, p = 0.008). Infection rates were higher in An. coluzzii mosquitoes (21/133 mosquitoes), estimated at 15.79% (CI: 9.59–21.99%) compared to An. gambiae s.s. mosquitoes (4/71), with approximately 5.63% (CI: 0.27–11.00%, χ² = 4.44; df = 1, p = 0.035). Resistant mosquitoes had a significantly higher prevalence of MB infection than susceptible mosquitos at 28.57% (CI: 16.74–40.40%) with an odds ratio of 3.33 (CI: 1.23–9.03, p = 0.017). These findings suggests that MB can be exploited as an alternative for vector control in Nigeria and Niger, but its possible association with pyrethroid resistance suggests that it should be taken into account as a potential confounder when designing insecticide resistance management strategies. Full article

Estimating the human impact on parasites in wildlife is essential to create efficient strategies to control diseases and improve public health. This study assessed the human influence on the parasite burden of the two commonest canine mesocarnivores, the red fox (N = 194) and the golden jackal (N = 151), in Europe. We compared the infracommunity crowding index, parasite diversity, prevalence, and abundance of different parasite taxa, and the presence of Echinococcus multilocularis between groups of hosts, such as jackals and foxes hunted at different distances from human settlements. The analysis of hosts’ distribution ascertained that 61.2% of the investigated wild canids were hunted in a 500–1750 m ring around the human settlements. Ancylostomatidae proved the most prevalent taxon (>60%), while Echinococcus multilocularis and Dipylidium caninum occurred least frequently. The two taxa that mostly contributed to the crowding of infracommunities were Ancylostomatidae and Toxocaridae, with a negative correlation between their abundances (Spearman’s ρ = −0.445, p < 0.001). Parasite infracommunities were more crowded in Echinococcus multilocularis infected foxes (p = 0.02) and jackals (p = 0.001). Our study highlighted that human modification of landscapes worsened the parasite burden of wild mesocarnivores, which could increase the public health risk of zoonotic parasites. Full article

Vector-borne parasitic diseases represent a critical public health challenge in Africa, disproportionately impacting vulnerable populations and linking human, animal, and environmental health through the One Health framework. In this review, we explore the existing burden of these diseases, particularly those that are underreported. Climate change, urbanization, the introduction of alien species, and deforestation exacerbate the emergence and reemergence of arthropod-borne zoonotic parasitic diseases like malaria, leishmaniasis, and trypanosomiasis, complicating control and disease elimination efforts. Despite progress in managing certain diseases, gaps in surveillance and funding hinder effective responses, allowing many arthropod zoonotic parasitic infections to persist unnoticed. The increased interactions between humans and wildlife, driven by environmental changes, heighten the risk of spillover events. Leveraging comprehensive data on disease existence and distribution coupled with a One Health approach is essential for developing adaptive surveillance systems and sustainable control strategies. This review emphasizes the urgent need for interdisciplinary collaboration among medical professionals, veterinarians, ecologists, and policymakers to effectively address the challenges posed by vector-borne zoonotic parasitic diseases in Africa, ensuring improved health outcomes for both humans and animals. Full article

Gastrointestinal parasites (GIPs) and tick infestations remain critical health challenges limiting cattle productivity in rural South Africa, particularly within communal farming systems. The Eastern Cape Province, characterized by high livestock densities and variable management practices, provides a unique context in which to examine parasitic burdens across systems. This study aimed to compare the prevalence, intensity, and diversity of GIPs and tick species in cattle raised under rural communal grazing versus communal feedlot systems in the Eastern Cape Province of South Africa. A total of 160 cattle (n = 80 per system) were randomly selected for fecal and tick examinations in community-based feedlots in Holela (Centane) and Gxwalibomvu (Tsomo), as well as from surrounding rural villages. Fecal samples were analyzed using the McMaster technique to determine fecal egg counts (FEC), while tick species were identified and counted from standardized body regions. Body condition scores (BCS) were recorded, and farmer practices related to parasite control were surveyed. Results showed significantly higher GI parasite prevalence and FEC in rural community cattle compared to feedlot cattle (p < 0.05), with Haemonchus contortus and Trichostrongylus spp. being the most prevalent. Similarly, rural cattle had significantly higher tick infestation rates, dominated by Rhipicephalus microplus and Amblyomma hebraeum. Logistic regression identified rural production system, poor body condition (BCS ≤ 2), and absence of recent deworming as significant risk factors for GI parasitism (p < 0.05). Strong negative correlations were found between BCS and both FEC (r = −0.63) and tick burden (r = −0.57). Additionally, rural farmers reported lower acaricide usage and greater reliance on traditional remedies. The study confirms that rural communal systems expose cattle to higher parasitic risks due to unmanaged grazing, limited veterinary support, and poor parasite control strategies. Communal feedlots, by contrast, offer more controlled conditions that reduce parasitic burden. Integrating strategic parasite management, farmer training, and expanded veterinary outreach is essential to improving cattle health and productivity in communal areas. Full article

Bovine trypanosomiasis, caused by Trypanosoma vivax, affects livestock productivity and is increasingly being reported in South America. This study aimed to detect and characterize Trypanosoma spp. infections, with a focus on T. vivax, in cattle from two distinct agroecological regions of central Argentina: a dairy-producing plain, located in the Espinal ecoregion, and a riparian zone, dedicated to beef production, located in the Delta and Islands of Paraná ecoregion. A total of 220 blood samples were collected from nine cattle farms and analyzed using real-time PCR, melting curve analysis, and the sequencing of 18S rRNA gene fragments. Trypanosoma vivax was detected at low prevalence (2.73%), exclusively in dairy cattle. In contrast, the prevalence of Trypanosoma theileri was much higher (10.91%), and it was found mainly in beef cattle from the riparian region. Phylogenetic analyses confirmed the species identity in all sequenced samples. No trypanosomes were observed by microscopy, and none of the animals showed clinical signs. The results indicate a differential distribution of T. vivax and T. theileri between regions and production systems. Although the study initially focused on T. vivax, the detection of T. theileri highlights the need to consider multiple Trypanosoma species in epidemiological surveys. This study contributes new data on the occurrence of bovine trypanosomes in central Argentina under extensive and semi-intensive management systems. Full article

This study aimed to explore and identify soil-dwelling nematophagous fungi (NF) from the “El Texcal” Ecological Reserve in Morelos, Mexico, and evaluate their potential as biological control agents against Haemonchus contortus infective larvae (HcL3), a major parasitic threat in livestock systems. The fungi were isolated from soil using the sprinkling of soil on water agar plates. The identification of NF was achieved using morphological identification keys, which was corroborated by molecular procedures using the PCR technique in the ITS4 and ITS5 regions. The nematocidal effects occasioned by these NF were examined through their predatory activity (PA) against HcL3 on water agar plates, and additionally, the larval mortality attributed to their liquid filtrates (LFs) was assessed at three different concentrations (25, 50, and 100 mg/mL) on 96-well microtiter plates. Two NF were identified and classified as two species of Dactylellina genus, namely D. haptospora (Dh) and D. phymatopaga (Dp). The PA exhibited by these NF were 94.79% for Dh and 68.88% for Dp; while their LFs showed 27.83% mortality for Dh and 32.86% for Dp at the highest concentration assessed. While the PA was notably high, the moderate larvicidal effect of the LF suggests that their efficacy may primarily rely on direct physical interaction rather than metabolite-mediated toxicity. The high PA demonstrated by these two isolates of NF indicates that they could be effective candidates for biological control agents against HcL3. Full article

Giardia duodenalis is a flagellated protozoan pathogen causing parasitic enteric disease outbreaks worldwide. Among detection methods, loop-mediated isothermal amplification (LAMP) has high selectivity and sensitivity, and the detection time is lower than that of conventional molecular methods. In this study, three published Giardia LAMP primer sets were tested and adapted to touchdown LAMP conditions. The measurement time, the volume of reagents, the effect of the denaturation step, different kinds of polymerases, and the presence or absence of betaine on the reaction were tested and evaluated. Based on the results of this study, the 66–60 °C range touchdown LAMP with the use of betaine, 90 °C denaturation step, Bst 2.0 WarmStart^® DNA Polymerase, and the primer set of Momoda et al. were the optimal conditions. We increased the analytical sensitivity of the LAMP reaction to 7.8- and 8-fold higher than the previously published methods for G. duodenalis assemblages A and B, with detection limits of 20 and 19.5 fg/assay, respectively, instead of 156 fg/assay. The detection time was less than 49 min for G. duodenalis assemblage A and less than 35 min for assemblage B, compared to the previously published 60 min. Our optimized LAMP protocol can be directly applied to improve Giardia LAMP tests in routine testing laboratories, could be implemented in standard diagnostic or environmental monitoring workflows, and can be used for the development of Giardia LAMP point-of-care devices or high-throughput systems. Full article

Archived, frozen tongues of 56 bobcats (Lynx rufus) from Oklahoma, USA, were tested for parasites. Testing for Sarcocystis infections included microscopic examination of unstained muscle squashes, histological sections of paraffin-embedded tissues, and molecular characterization. By a combination of both compression methods and histology, sarcocysts were found in 28 (50.0%) of 56 bobcats. In compression preparations, the sarcocyst wall appeared thin and protrusions were not clear. Histologically, tissues were degraded and, in most tongues, only a few sarcocysts were found, except bobcat #35. Multilocus genotyping utilizing 18S rRNA, 28S rRNA, and cox1 genes yielded sequences exhibiting 98–100% identity with both Sarcocystis arctica and Sarcocystis caninum isolates available in the NCBI database. Hepatozoon rufi-like meronts were found in two tongues and is the first report of Hepatozoon infections in bobcats in Oklahoma. Full article

This research introduces a novel method that integrates both unsupervised and supervised learning, leveraging SimCLR (Simple Framework for Contrastive Learning of Visual Representations) for self-supervised learning along with different pre-trained models to improve microscopic image classification of Babesia parasite in canines. We focused on three popular CNN architectures, namely ResNet, EfficientNet, and DenseNet, and evaluated the impact of SimCLR pre-training on their performance. A detailed comparison of the different variants of ResNet, EfficientNet, and Densenet in terms of classification accuracy and training efficiency is presented. Base models such as different variants of the ResNet, EfficientNet, and DenseNet models were utilized within the SimCLR framework. Firstly, the models were pre-trained on unlabeled images, followed by training classifiers on labeled datasets. This approach significantly improved the robustness and accuracy, demonstrating the potential benefits of combining contrastive learning with conventional supervised techniques. The highest accuracy of 97.07% was achieved by Efficientnet_b2. Thus, detection of Babesia or other hemoparasites in microscopic blood smear images could be automated with high accuracy without using a labelled dataset. Full article

(1) Background: Coproparasitological techniques are fundamental in veterinary medicine for diagnosing intestinal parasitic infections and form a core part of clinical training. Due to their procedural nature, teaching these techniques can benefit from scalable, visual tools that support skill acquisition and self-directed learning. This study aimed to evaluate the impact of instructional videos on students’ understanding and perceptions of coproparasitological methods. (2) Methods: A cross-sectional study was conducted with 110 veterinary students who viewed instructional videos covering 11 coproparasitological techniques. Their knowledge was assessed using a 17-item multiple-choice exam. Additionally, a structured opinion questionnaire was used to gather student feedback on the clarity and usefulness of the videos. (3) Results: Fourteen of the seventeen exam items were answered correctly by more than 80% of participants, with one item reaching 96.4% accuracy. Regarding perceptions, 94% of students rated the videos as “very clear”, and 94% as “very useful”, highlighting strong acceptance and satisfaction. (4) Conclusions: Instructional videos significantly supported students’ comprehension and were perceived as effective learning tools. Their integration into veterinary parasitology curricula is recommended to reinforce technical training, improve learning outcomes, and address limitations in access to hands-on instruction, especially in resource-constrained educational settings. Overall, instructional videos represent a valuable strategy to strengthen practical competencies in veterinary parasitology education. Full article

Parasites of the genus Trichinella are widely distributed and infect a wide range of domestic and wild animals. Their presence spans across various continents, impacting agricultural and wildlife ecosystems alike. In Argentina, Trichinella spiralis, Trichinella patagoniensis, and Trichinella pseudospiralis have been detected infecting both domestic and wild animals. The aim of the present study is to detect Trichinella spp. in samples from domestic pigs and wildlife across Argentina between 2019 and 2024 and to identify these parasites at the species level. A total of 216 samples from domestic and wild animals underwent artificial digestion. In cases where a positive result was obtained, muscle larvae were further processed using PCR targeting the ESV region. Samples originating from 16 animals were analyzed. Among the animals tested, 52 were positive for Trichinella spp., including two pumas infected with T. patagoniensis; 43 domestic pigs, with 34 identified as T. spiralis at the species level; and seven wild boars, with five identified as T. spiralis at the species level. The present study enhances our understanding of the distribution and transmission dynamics of Trichinella among domestic and wild animals in Argentina. Full article

Metacyclogenesis is a critical process in the Trypanosoma cruzi life cycle. This transition naturally occurs in an insect vector’s gut. Although Triatomine Artificial Urine (TAU) medium is the widely adopted approach to metacyclogenesis in vitro, its efficiency decreases with prolonged epimastigote culture, limiting the availability of metacyclic trypomastigotes for study. We aimed to establish a practical and efficient method for generating high concentrations and purities of metacyclic trypomastigotes in vitro. Epimastigotes of the Dm28c strain were exposed to pH shifts in nutrient-rich (MT-LIT) and nutrient-poor (M16) media, under static or agitated conditions. Both media promoted higher metacyclogenesis rates than TAU, with epimastigotes’ adherence to the substrate being a crucial factor. Metacyclogenesis efficiency varies depending on the strains and culture conditions. Notably, both LIT and M16 at pH 6 produced metacyclic trypomastigotes with infective capacity on Vero cells. Under these conditions, a variety of intermediate forms were observed compared to those induced by TAU metacyclogenesis. Our findings further emphasize the strain-dependent nature of optimal in vitro metacyclogenesis conditions and offer new opportunities for studying the intermediate forms involved in this essential process. Full article

Dogs harbour a wide range of endoparasites, many of which pose a significant risk to public health globally due to their zoonotic potential. Addressing the dynamics of zoonotic parasites comprehensively requires epidemiological studies under the One Health paradigm, incorporating multidisciplinary methodologies to explore the complex interactions among humans, animals and the environment. The present study aimed to investigate the presence of canine parasites in public green places (PGPs) in Tandil, Argentina, using epidemiological and geographical tools to enhance efforts towards the prevention and control of canine parasitic diseases impacting public health. Between August 2024 and January 2025, 893 canine faecal samples were collected through a randomised two-stage sampling process from 92 public green places. The overall prevalence of intestinal parasites was 29.9% and the identified parasites were Trichuris vulpis, Ancylostoma caninum, Eucoleus spp., Uncinaria stenocephala, Toxascaris leonina, and Cystoisospora sp. Risk factors identified included the presence of playgrounds and a higher dog density, while protective factors comprised sampling during spring vs. winter and presence of areas of bare soil on the public green places. Spatial analysis revealed clusters of high prevalence in areas with lower socioeconomic status, and clusters of low prevalence in higher socioeconomic areas. These findings emphasise the need for targeted preventive measures, including responsible pet ownership policies. Moreover, the methodological approach adopted could be replicated in other regions to enhance public health protection and mitigate the risks associated with zoonotic parasitic diseases. Full article