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Research on the molecular genetics of Echinococcus has advanced significantly owing to its relevance in understanding genetic variation, host-parasite interactions, and the transmission of Echinococcus species. A bibliometric analysis was performed using RStudio (Bibliometrix) and VOSviewer to evaluate molecular genetic research on Echinococcus spp. published between 1985 and 2025. Data were extracted from Scopus, Web of Science, PubMed, Europe PMC, and ProQuest. The analysis revealed a steady rise in publications on Echinococcus molecular genetics, accelerating from the early 2000s and peaking around 2017, with a slight decline after 2023, reflecting fluctuations in research activity. Comparative analysis showed Echinococcus consistently surpassed Schistosoma, Taenia, and soil-transmitted helminths, peaking at 60 articles in 2020-2021. Early publications achieved high mean Total Citations (TC) per year, followed by a stable trend, indicating lasting impact. Leading journals included Parasitology Research (Germany; 70 articles, H-index 114), Veterinary Parasitology (Netherlands; 62, H-index 150), Parasitology (UK; 53, H-index 173), Acta Tropica (Netherlands; 34, H-index 122), and PLOS Neglected Tropical Diseases (USA; 28, H-index 172). Tehran University of Medical Sciences (54 articles) led institutions. Influential authors included D. P. McManus and T. Romig. Multinational studies (484 publications) had higher citations than single-country (474). Iran (121), China (116), and Italy (53) led global contributions, emphasising collaboration, genotyping, phylogeny, and veterinary applications. This bibliometric study underscores the evolving trends in Echinococcus molecular genetics, providing valuable insights for researchers and stakeholders to guide future investigations and collaborative strategies in controlling echinococcosis.

The temporal dynamics of parasite communities of the Three-spot cichlid Amphilophus trimaculatus Günther 1867 was examined during an annual cycle. A total of 770 fishes were collected between March 2019 and February 2020 from a tropical costal lagoon. Thirteen taxa of metazoan parasites were identified, two of monoxenous and 11 of heteroxenous parasites. No significant changes were observed in the species composition of parasite communities in A. trimaculatus during a 12-yr period (2008-2020). The prevalence of infection of six heteroxenous parasites Austrodiplostomum ostrowskiae Dronen, 2009, Cladocystis cf. trifolium Poche, 1926, Clinostomum cf. tataxumui Sereno-Uribe, Pinacho-Pinacho, García-Varela et Pérez-Ponce de León, 2013, Crassicutis cichlasomae Manter, 1936, Southwellina cf. hispida Witenberg, 1932 and Contracaecum sp. varied between sampling months, and/or climatic seasons. Some species were more prevalent during some months of the dry season, while others during the rainy season, suggesting that these parasite populations respond differently to environmental changes. The environmental changes generated by the dry/rainy cycle may have affected the availability of intermediate host populations, and the feeding and reproductive behaviour of the host. Temporal variations in the infection levels of some parasite species generated important changes in the structure of the component communities over time. This study allows us to appreciate the sensitivity of parasite-host systems to environmental variability, and suggests that alterations to hydrological regimes could have significant consequences on parasite biodiversity in tropical brackish water environments.

Markers of chronic infection Toxoplasma gondii (Nicolle et Manceaux, 1908) have been associated with suicidal self-directed violence (SSDV). We present the results of the first study relating T. gondii IgG serology with suicide attempts and suicidal ideation in United States Veterans, known to have higher suicide rates than members of the general population. We also related T. gondii serology to SSDV risk factors, including valid and reliable measures of trait impulsivity, aggression, self-reported depression, and sleep disturbance. We recruited 407 Veterans enrolled at three Veterans Affairs Medical Centers with mean (S.D.) age = 45.6 (11.6) years; 304 men (74.7%); 203 with a history of SSDV and 204 with no history of any self-directed violence (SDV). Seropositivity and serointensity, categorised as high (top quartile) or low (lower three quartiles), were analysed in relationship to SSDV, suicidal ideation and clinical risk factors using age and gender-adjusted linear and logistic methods, after transformations and nonparametric tests when appropriate. Associations between seropositivity and SSDV and its risk factors were not significant in all groups. High serointensity, while not associated with SSDV or repeat suicide attempts, was positively associated with suicidal ideation, depression, impulsivity, and daytime dysfunction due to sleepiness (p < 0.05), but only in Veterans with a history of SSDV. In Veterans without a history of SDV, no associations were significant. These associations remained significant after adjustment for certain socioeconomic factors (i.e., income, homelessness, military rank). Including education in the model downgraded the statistical significance of suicidal ideation and depression to statistical trends, but the significance of associations with impulsivity and daytime dysfunction due to sleepiness remained. Major limitations include the cross-sectional design, overall low seropositivity within the sample, and potentially spurious results due to multiple comparisons. Thus, the results of this report need to be replicated in larger samples, ideally longitudinally.

Clinostomum complanatum (Rudolphi, 1814) is known as a food-borne zoonotic parasite using freshwater fish as intermediate host, although in its native distribution area in Europe, the Danube and Po basins and the northeast of Italy, no cases have been reported. This study reports a new geographic location outside the native distribution range of this parasite. We detected high infection levels of C. complanatum in wild perch (Perca fluviatilis Linnaeus) from the Doubs River in continental France. Clinostomum complanatum reached a prevalence of 97% and mean intensity of 5.8 cysts per fish in 33 fish examined, with most fish already infected by the age of two years. No correlations were observed between fish traits (standard length, weight, age and sex) and the number of parasites. The distribution of C. complanatum cysts in the fish body was not random. The tissue surrounding the opercula and branchial cavity, and muscles along the lateral line and near the pectoral, dorsal and caudal fins were the preferred sites of infection. Morphological identification was confirmed with molecular data. The French specimens shared identical mt cox1 haplotypes with specimens from Italy. The distribution of this exotic parasite in freshwaters in continental France deserves further research. Under the current French law, the parasite occurrence represents an economic loss for the local freshwater aquaculture industry, and a possible zoonotic risk for consumers if undetected, especially when raw or marinated fish is consumed. We provided a list of all reported hosts for C. complanatum from the western Palaearctic, discussed the knowledge gap regarding the zoonotic risk of C. complanatum in Europe, and highlighted the lack of policy that may increase the hazards posed by food-borne emerging parasites and their broader ecological impacts as alien species in freshwaters in Europe.

A new species of Acanthocephala is described based on specimens found parasitising the intestine of the gafftopsail pompano Trachinotus rhodopus Gill in the State of Oaxaca, off the Pacific coast of Mexico. Rhadinorhynchus villalobosi sp. n. differs from the other 25 species of the genus known from the Pacific Ocean by a combination of morphological traits, such as the fewer number of rows of hooks along the proboscis, the distribution of spines of the trunk forming two fields, the position of genital pore, subterminal in both sexes, a shorter neck and cement glands, among others. The phylogenetic analyses based on sequences of the nuclear 18S and 28S rRNA genes, as well as the mitochondrial cox1, all agree that R. villalobosi sp. n. is part of the genus, and closely related to Rhadinorhynchus trachinoti Grano-Maldonado, Sereno-Uribe, Hernández-Payán, Pérez-Ponce de León et García-Varela, 2025, a recently described Mexican species, despite the marked morphological differences between the two and being distributed in different areas.

The present paper comprises a systematic survey of trematodes and acanthocephalans based on helminthological examinations of 64 specimens of 14 species of freshwater fishes, belonging to six families of four fish orders, mostly from localities in Hubei Province, central China, collected in the autumn of 2002. A total of 15 trematode species (in 12 families) and 5 acanthocephalan species (in four families) was recorded. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Some findings represent new host and geographical records. New acanthocephalan genus Quadrihexaspiron gen. n. (Neoechinorhynchidae) is erected to accommodate two species from China, Quadrihexaspiron spinibarbi (Yu et Wang, 1997) comb. n. (type species) and Quadrihexaspiron parabramis (Yin et Wu, 1984) comb. n., originally placed in Hexaspiron Dollfus et Golvan, 1956; Hexaspiron is recognised as a genus belonging to Quadrigyridae. The trematode species Orientocreadium elegans Besprozvannykh, Ermolenko et Deveney, 2009 is considered to be possibly identical with Orientocreadium pseudobagri Yamaguti, 1934, whereas the morphologically similar acanthocephalan species Micracanthorhynchina dakusuiensis (Harada, 1938) and Micracanthorhynchina brevelemniscus Lisitsyna, Barčák, Orosová, Fan et Oros, 2023 may prove to be conspecific with Micracanthorhynchina motomurai (Harada, 1935). A re-examination of the type specimens of Neoechinorhynchus afghanus Moravec et Amin, 1978 (Acanthocephala), a parasite of fishes in Afghanistan, revealed the presence of minute trunk spines in this species and, consequently, it is transferred to the genus Quadrigyrus Van Cleave, 1929 (Quadrigyridae) as Quadrigyrus afghanus (Moravec et Amin, 1978) comb. n.

Cercariae are motile infectious larval stages of digenetic trematodes that emerge from their molluscan first intermediate host to seek the next host in their life cycle. A crucial transmission strategy of trematodes involves releasing the maximum number of cercariae at times that coincide with the presence and activity of the next hosts, thereby increasing the likelihood of successful infection and continuation of the parasite's life cycle. We investigated the cercarial emergence of two furcocercous (with forked tail) trematodes Tylodelphys clavata (von Nordmann, 1832) and unidentified species of Sanguinicola Plehn, 1905 from naturally infected Ampullaceana balthica (Linnaeus) and Radix auricularia (Linnaeus) snails under natural light and constant temperature conditions. Both trematodes, which are important fish pathogens, showed distinct daily emergence rhythms influenced by light intensity, with emergence peaking at sunset and night for T. clavata and at night for Sanguinicola sp. The daily emergence rhythms of T. clavata cercariae were consistent in both summer and autumn, indicating adaptability to natural changes in seasonal photoperiods. The interspecific differences in emergence patterns are likely related to the behavioural patterns of upstream, i.e., next in the life cycle, fish hosts. Cercarial output also varied between trematode species and seasons, likely due to combined effects of snail size, intensity of trematode infection in snails and size of cercariae rather than seasonal temperatures. The trematodes were molecularly characterised using mitochondrial (cox1) and nuclear (28S rDNA and ITS1-5.8S-ITS2) regions to confirm their identity and facilitate future studies. This study highlights the importance of light-regulated and host-synchronised cercarial emergence rhythms for increased trematode transmission success and reveals significant variation in cercarial output influenced by environmental and biological factors, contributing to a deeper understanding of trematode ecology and disease management.

Chagas disease, caused by the kinetoplastid Trypanosoma cruzi (Chagas, 1909), and transmitted by triatomine bugs, poses a significant public health challenge. Variability in the susceptibility of different triatomine species to T. cruzi infection can profoundly influence disease transmission dynamics and control measures. In this study, we assessed the susceptibility to T. cruzi infection in the first and third nymphal stages across eight triatomine species to T. cruzi infection using experimental inoculation with the NINOA strain and optical microscopy. The evaluated species were Dipetalogaster maximus (Uhler), Triatoma bassolsae (Alejandre-Aguilar, Nogueda-Torres, Cortéz-Jiménez, Jurberg, Galvão, Carcaballo), T. infestans (Klug), T. lecticularia (Stål), T. mexicana (Herrich-Schaeffer), T. pallidipennis (Stål), T. phyllosoma (Burmeister) and T. picturata (Usinger). The results indicated that T. bassolsae exhibited the highest susceptibility to infection, followed by T. pallidipennis and D. maximus. Our analysis also revealed that T. cruzi (NINOA) infection was significantly associated with triatomine species rather than nymphal stage (p < 0.0001), with substantial variability observed in susceptibility among species (p < 0.001). We ranked triatomine species susceptibility to T. cruzi infection as follows: T. bassolsae > D. maximus = T. pallidipennis = T. picturata = T. mexicana > T. phyllosoma = T. lecticularia = T. infestans. These findings enhance our understanding of T. cruzi transmission dynamics and offer valuable insights for the development of effective control strategies against this neglected tropical disease.

Latent infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) has been repeatedly correlated with behavioural and physiological changes in both humans and animals. While classically regarded as a parasite transmitted via ingestion or vertical (transplacental) transmission, accumulating evidence suggests that sexual transmission may also contribute to its epidemiology. This review explores the hypothesis that some behavioural effects of toxoplasmosis - especially those related to attraction, sexual activity, and mate choice - may have evolved to facilitate sexual transmission of the parasite. We summarise findings from animal models and human studies that show modified sexual preferences, altered sexual activity, enhanced attractiveness in infected individuals, and elevated prevalence of T. gondii in groups exhibiting high sexual activity or non-traditional sexual behaviour patterns. Particular attention is given to the role of testosterone, which may mediate both behavioural changes and reproductive consequences, such as shifts in offspring sex ratios and fertility outcomes. Direct detection of the parasite in semen and evidence of transmission through insemination in non-human species further support the plausibility of this route. The observed behavioural effects may also intersect with mechanisms previously thought to enhance predation risk, such as altered fear responses to felid odours. Taken together, these findings point to the possibility that sexual transmission, while likely secondary in humans, may have played a more substantial role in the evolutionary history and current ecology of T. gondii than previously appreciated. This perspective also provides an alternative interpretative framework for understanding the broad spectrum of phenotypic changes associated with latent toxoplasmosis. Further interdisciplinary research is required to clarify the relative contribution of sexual transmission to the parasite's life cycle and to assess its implications for public health and theory of host-parasite coevolution.

During November of 2007, parasitic nematodes were collected from 161 specimens of 32 freshwater fish species in the Lacantún River of the Lacandon rain forest of Chiapas, southern Mexico. Recent detailed morphological and taxonomic studies of this material revealed the presence of 17 nematode species (12 adult and 5 larval) of nine families, including Cucullanus potamarii sp. n. from the intestine of the ariid catfish Potamarius usumacintae Betancur-R et Willink, which is endemic to the Usumacinta River basin to which the Lacantún River belongs. This new species is mainly characterised by deirids and the excretory pore located far posterior to the level of the oesophago-intestinal junction, which is an almost unique feature among its congeners. Most parasites are briefly described and illustrated, and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Some findings represent new host and geographical records. Cucullanus oaxaquensis Caspeta-Mandujano, Salgado-Maldonado et Martínez-Ramírez, 2010 is considered a junior synonym of Cucullanus angeli Cabañas-Carranza et Caspeta-Mandujano, 2007, and Neocucullanus marcelae Ramallo, 2012 a species inquirenda. Based on absence of relevant morphological differences, Rhabdochona ictaluri Aguilar-Aguilar, Rosas-Valdez et Pérez-Ponce de León, 2010 is considered a synonym of Rhabdochona kidderi Pearse, 1936.

Toxoplasma gondii (Nicolle et Manceaux, 1908), an intracellular parasite that causes toxoplasmosis, infects a third of the human population. Latent toxoplasmosis has been linked to altered immune responses, including elevated proinflammatory cytokines. In early pregnancy, the immune system adapts to balance inflammation and foetal tolerance. This study assessed whether pregnant women in the first trimester infected with Toxoplasma gondii have different cytokine levels than uninfected women. This study also examined whether women with discordant test results for toxoplasmosis represent a distinct group or a mixed group composed of infected women with unusually low levels of anti-Toxoplasma antibodies and uninfected women with high levels of cross-reacting antibodies. We measured 18 cytokines (IL-1β, IL-1ra, IL-2, IL-4, IL-7, IL-9, IL-17A, Eotaxin, FGF basic, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF-BB, RANTES, TNF-α) in 78 pregnant women, classified as Toxoplasma-positive, Toxoplasma-negative or Toxoplasma-discordant (negative by IgG ELISA, positive by complement fixation test [CFT]). Using exploratory factor analysis, we identified two factors, the first explaining 29.6% and the second 24.9% of the total variability in cytokine concentrations. Toxoplasma-positive women scored significantly higher in the second factor, primarily associated with cytokines linked to Th1-driven inflammation and cellular immunity. Specifically, these women exhibited elevated levels of IL-1β, IL-1ra, IL-2, FGF basic and PDGF-BB compared to Toxoplasma-negative women. This finding suggests that pregnant women with latent toxoplasmosis experience some degree of chronic inflammation. Additionally, our results indicate that Toxoplasma-discordant women are likely Toxoplasma-negative individuals with detectable anti-Toxoplasma IgM antibodies. However, as this study focused on pregnant women, further research is necessary to validate these conclusions in broader populations.

Ixodes inopinatus Estrada-Peña, Nava et Petney, 2014 was described in 2014 from the Iberian Peninsula and later reported from Algeria, Morocco, Tunisia, Germany, Austria and Romania. However, recent studies raised serious doubts about the presence of I. inopinatus in Central Europe and reported hybridisation between the Ixodes ricinus (Linnaeus, 1758) and I. inopinatus. In this study, we selected a locally common rodent host, the edible dormouse Glis glis (Linnaeus) (Rodentia: Gliridae), to study the prevalence of these two tick species and their hybrids in a Central European woodland. The TROSPA nuclear gene and the COI mitochondrial gene were used for tick identification. Overall, 581 dormice were screened and 383 I. ricinus, 17 I. ricinus/inopinatus hybrids and no I. inopinatus were found. Co-infection of I. ricinus and hybrids was found on 11 dormice with the overall prevalence of I. ricinus 28.8% and hybrids 2.5%. Seasonal occurrence of I. ricinus and hybrids reached a peak in August. Edible dormouse males were more frequently infected than females and larvae of both tick taxa greatly outnumbered the nymphs. Detection of a large number of hybrid larvae on this mammal host demonstrates that tick hybridisation likely occurs further north and outside the originally described distribution range of I. inopinatus.

A metabolic disease resulting in elevated blood glucose levels, type-2 diabetes affects approximately 462 million people globally. Although its prevalence appears to be increasing, type-2 diabetes has been associated with various potentially preventable risk factors, including infectious diseases. The protozoal infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) has been associated with type-2 diabetes in two previous meta-analyses. Since the publication of the last meta-analysis supporting an association between type-2 diabetes and T. gondii, several new primary studies have investigated this association. In this meta-analysis, we sought to further characterise the association between type-2 diabetes and T. gondii. We identified primary studies using PubMed, Embase, Scopus and Web of Science. Twenty-five studies met our inclusion criteria for a total of 4,639 patients with type-2 diabetes and 3,492 controls. Eighteen primary studies found a positive association between type-2 diabetes and T. gondii, whereas seven did not. Using a frequentist random-effects meta-analysis model, we found an overall summary odds ratio of 2.77 (95-percent confidence interval: 2.03-3.76), suggesting that the odds people will have type-2 diabetes is 2.7 times higher for people seropositive for T. gondii. Future studies should investigate this association in additional geographical regions and explore whether this association is due to the immunosuppressive effects of type-2 diabetes or whether T. gondii directly or indirectly affects glucose metabolism, or both.

While the identification of adult monogeneans primarily relies on morphological criteria, the morphology of a number of monogenean larvae (oncomiracidia) is to this day scarcely described. Yet, oncomiracidium plays a crucial role in the life cycle of the parasite, being responsible for the detection and localisation of its host, as well as for its attachment to this host. Few studies investigated the external morphological structures related to these functions, especially in Monopisthocotylea. The present study focuses on the early life stages (egg and oncomiracidium) of Lamellodiscus erythrini Euzet et Oliver, 1967, which are accurately described for the first time by light and scanning electron microscopy. Eggs of L. erythrini are smooth, tetrahedral and extended by a long polar filament. Freshly laid, the egg is brown, opaque, impermeable and becomes transparent as it matures, revealing the larva and its eye spots. When the egg matures, the egg casing exhibits functional weak points all around the operculum through which the larva emerges. The larva of L. erythrini is elongated, cylindrical and has a highly developed ciliation covering three areas: an anterior zone, a pleural zone, and a posterior cone. The ciliated cells are contiguous and are organised in a structured mosaic of spherical droplets, each cilium inserted into one. The larval tegument presents microvilli as well as 9 pairs of dorsal sensilla. The haptor is a closed structure consisting of 14 sclerotised hooklets, 12 arranged in a circle, and one pair positioned at the centre of the haptor. The possible link between these morphological structures and larval behaviour is discussed.

The nematode Spinitectus notopteri Karve et Naik, 1951 was collected from two species of freshwater fish belonging to the family Notopteridae, namely Chitala ornata (Gray) and Notopterus notopterus (Pallas), at Khun Thale Swamp in Surat Thani province of southern Thailand. The overall prevalence of the parasite was found to be 88% (94 fish infected/106 fish examined). A higher prevalence was found in C. ornata (96%), while a higher intensity was noted for N. notopterus (117 parasites/fish). The most important morphological characters were the presence of cephalic and cuticular structures, precloacal ridges, and genital papillae. Specimens were genetically characterised using cox1 mtDNA. Morphological characteristics were most similar to Spinitectus petterae Boomker, 1993 from Clarias gariepinus (Burchell) in Africa, while the genetic data were dissimilar to all available data for the genus. Therefore, the identification of nematode specimens using a combination of morphological and molecular techniques is stressed. This study also presents the first molecular analysis of S. notopteri infecting Thai freshwater fish and a new geographical record for S. notopteri.

Bacteria Borrelia burgdorferi s. l. and even more the protist Toxoplasma gondii Nicolle et Manceaux, 1908, are known to affect the behaviour and mental health of their animal and human hosts. Both pathogens infect a significant fraction of human population, both are neurotropic and survive in the host's body for a long time. While latent infections were thought to be clinically asymptomatic, recent studies suggest otherwise, revealing adverse effects on human health. It was hypothesised that the specific behavioural effects of these pathogens may be side effects of general health impairments in infected individuals. This hypothesis was tested using about one hour-long survey consisting of questionnaires and performance tests on a cohort of 7,762 members of the internet population. Results showed that individuals infected with T. gondii reported worse physical and mental health, and those infected with Borrelia spp. reported worse physical health than uninfected controls. Furthermore, infected and noninfected individuals differed in several personality traits, including conscientiousness, pathogen disgust, injury disgust, Machiavellianism, narcissism, tribalism, anti-authoritarianism, intelligence, reaction time, and precision. While the majority of behavioural effects associated with Borrelia infection were similar to those associated with Toxoplasma infection, some differences were observed, such as performance in the Stroop test. Path analyses and nonparametric partial Kendall correlation tests showed that these effects were not mediated by impaired health in infected individuals, contradicting the side effects hypothesis.

Females of species of Lamproglena von Nordmann, 1832 are parasitic on the gills of teleost fishes and the 38 nominal species are based on mainly morphological data. Only four of these species have been genetically characterised and no mitochondrial data are available for the genus. The present study aimed to provide representative ribosomal DNA (rDNA) data for two additional species of Lamproglena from Africa: Lamproglena clariae Fryer, 1956 and Lamproglena hoi Dippenaar, Luus-Powell et Roux, 2001, alongside mitochondrial DNA (mtDNA) for these and two other African species, Lamproglena hemprichii von Nordmann, 1832 and Lamproglena monodi Capart, 1944. The four species were collected from Clariidae, Cyprinidae, Alestidae and Cichlidae, respectively. Representative 18S rDNA and 28S rDNA data were obtained for L. clariae and L. hoi, while cox1 mtDNA was obtained for all four species. The respective haplotypes supported the distinctness of all species using all three gene regions investigated. Interestingly, species appeared to be grouped more by geographical origin than host family, with L. hoi more closely related to other African species than to Asian species also collected from cyprinid hosts. Even though the results presented here greatly add to the molecular data available for Lamproglena, there are still 32 (>80%) species for which no genetic data are available. The interpretation of the results presented here is thus preliminary and much more data are required before the phylogeny of this genus, and other members of the family, such as Lernaea Linnaeus, 1758, can be studied appropriately.

Species of Blastocystis Alexieff, 1911 are anaerobic intestinal protists found in humans and many kinds of animals that mainly cause diarrhea, abdominal pain and other clinical symptoms. At present, data on the prevalence and subtype diversity of species of Blastocystis in domestic rabbits are very limited. The purpose of this study was to characterise the infection rate and gene subtype distribution of Blastocystis sp. in domestic rabbits in Henan Province, Central China, and provide foundation for prevention and control of the disease caused by Blastocystis sp. in domestic rabbits. DNA was extracted from 286 fresh rabbit faecal samples collected from four areas of Henan Province, Central China. All DNA samples were screened using PCR and positive samples were sequenced to identify individual subtypes based on the small ribosomal subunit (SSU rRNA) gene. The overall infection rate of Blastocystis sp. in domestic rabbits in Henan Province was 15% (43/286). Three subtypes were identified, including ST1 (26/43, 60%), ST3 (5/43, 12%) and ST7 (12/43, 28%), all of which belonged to potentially zoonotic subtypes, ST1 was the dominant gene subtype. These results showed that infection with Blastocystis sp. was common in domestic rabbits in Henan Province, Central China, and was represented by zoonotic subtypes. Therefore, special attention should be paid to reduce the risk of transmission of Blastocystis sp. from domestic rabbits to humans.

Ticks are important vectors of various pathogens that cause infectious diseases in humans. Endosymbiotic bacteria have been explored as targets for tick and tick-borne disease control. However, the tick bacterial community on Hainan Island, which is the largest tropical island in China and has an environment favourable to ticks, has not yet been studied. In this study, we surveyed the bacterial community of ticks collected from grass in one village in Haikou. A total of 20 ticks were morphologically and molecularly identified as Haemaphysalis spp. The tick bacterial 16S rRNA hypervariable region amplicon libraries were sequenced on an Illumina MiSeq platform. A total of 10 possible bacterial genera were detected, indicating a low-diversity bacterial community profile. The dominant bacterial genus, Massilia, accounted for 97.85% of the population. Some other bacterial genera, including Arsenophonus and Pseudomonas, have been reported to play a role in tick development and tick-borne pathogen transmission in other tick species. Overall, the study highlights the first descriptive understanding of the tick bacterial community on Hainan Island and provides a basis for deciphering the interactions between the tick microbiome and tick-borne pathogens.

We provide the first ultrastructural evidence of the secretion of extracellular vesicles (EVs) across all parasitic stages of the tapeworm Schistocephalus solidus (Müller, 1776) (Cestoda: Diphyllobothriidea) using a laboratory life cycle model. We confirmed the presence of EV-like bodies in all stages examined, including the hexacanth, procercoids in the copepod, Macrocyclops albidus (Jurine, 1820), plerocercoids from the body cavity of the three-spined stickleback, Gasterosteus aculeatus Linnaeus, and adults cultivated in artificial medium. In addition, we provide description of novel tegumental structures potentially involved in EV biogenesis and the presence of unique elongated EVs similar to those previously described only in Fasciola hepatica Linnaeus, 1758 (Trematoda), Hymenolepis diminuta (Rudolphi, 1819) (Cestoda), and Trypanosoma brucei Plimmer et Bradford, 1899 (Kinetoplastida).

Two species of Spinitectus Fourment, 1884 have been recorded from southern Africa, namely Spinitectus polli Campana-Rouget, 1961 and Spinitectus petterae Boomker, 1993, both from the Limpopo River system. Spinitectus petterae was described from North African catfish, Clarias gariepinus (Burchell), whereas S. polli infects squeakers, Synodontis spp. During parasitological surveys in the Vaal River system (Orange River catchment), Spinitectus specimens were collected from C. gariepinus. These systems are adjacent but not connected. Therefore, this study aimed to identify the specimens collected using morphological and molecular techniques. The morphological study included light and scanning electron microscopy of whole specimens and excised spicules. Specimens were genetically characterised using 18S rDNA, 28S rDNA and cox1 mtDNA. Additionally, immature specimens of S. petterae were collected near the type locality. Morphological characteristics were most similar to S. petterae from C. gariepinus, whereas genetic data were dissimilar to all available data for the genus. Additional morphological characteristics noted for S. petterae in the present study were the details of the left and right spicule structure and the porous structures on the pseudolabia. Specimens from the Vaal River system differed from those originally described as S. petterae by additional spines posterior to the third ring, lacking caudal alae and variable total body and male oesophagus length. Based on 18S rDNA, haplotypes from the type locality varied only slightly from the study material, supporting the morphological identification. However, 28S rDNA and, more conspicuously, cox1 mtDNA displayed substantial variation between specimens from these localities, which needs further investigation. Haplotypes generated in the present study were highly dissimilar to those characterised for S. petterae from Tanzania and Egypt. Nevertheless, the nematodes collected from C. gariepinus in the Vaal River system are considered S. petterae. This study expands the geographical distribution and adds additional morphological and genetic information for S. petterae, contributing to the limited knowledge of African species of Spinitectus.

A total of 1,724 beef and 2,941 dairy cattle older than one year from 66 beef and 67 dairy farms in the Czech Republic were examined for the presence of rumen and liver fluke eggs in 2019-2022. Out of 227 positive animals, all were positive for paramphistome and five for fasciolid eggs. Molecular analysis of the ITS2 rDNA revealed the presence of Calicophoron daubneyi (Dinnik, 1962) and Fasciola hepatica Linnaeus, 1758. Faecal egg count (FEC) showed low infection intensity (12 EPG) in animals infected with F. hepatica and high variability in C. daubneyi infections (2-589 EPG). Efficacy of oxyclozanide, albendazole, ivermectin, and closantel against C. daubneyi infection was evaluated at eight beef cattle herds. Faecal samples were collected from all positive animals at 0 and 21days post-treatment. Based on FEC, albendazole, ivermectin and closantel reduced the number of C. daubneyi eggs shed by 0-9.9%, with no effect on the number of infected animals. The use of oxyclozanide on two beef farms showed 100% efficacy against C. daubneyi and F. hepatica. Follow-up examination 5-6 months after drug application showed reinfection of most animals with C. daubneyi, but the FEC was significantly lower. The finding of four dairy cows infected with C. daubneyi housed in a stable without pasture suggests the possibility of the infection being introduced through roughage.

In an effort to expand knowledge of Clade 3-one of the ten clades that compose the non-monophyletic order 'Tetraphyllidea' all current members of which parasitise orectolobiform sharks-we targeted species of orectolobiform sharks that had not previously been examined for 'tetraphyllidean' cestodes. That work led to the discovery of three new species off Australia and Taiwan. Ambitalveolus gen. n. was erected to accommodate these species. Ambitalveolus costelloae gen. n. et sp. n., Ambitalveolus kempi sp. n., and Ambitalveolus penghuensis sp. n. differ from one another in scolex size, genital pore position, and number of marginal loculi, proglottids, and testes. Among 'tetraphyllideans', the new genus most closely resembles the two other genera in Clade 3. It differs from Carpobothrium Shipley et Hornell, 1906 in lacking anterior and posterior flap-like extensions of its bothridia; instead, its bothridia are essentially circular. It differs from Caulopatera Cutmore, Bennett et Cribb, 2010 in that its vitelline follicles are in two lateral bands, rather than circum-medullary, and in that its bothridia bear, rather than lack, conspicuous marginal loculi. A key to the three genera in Clade 3 is provided. A phylogenetic analysis including new sequence data for one of the three new species of Ambitalveolus gen. n., the only species of Caulopatera, and all four described species and one undescribed species of Carpobothrium supports previously hypothesised close affinities between Caulopatera and Carpobothrium, with the new genus as their sister group. This is the first report of 'tetraphyllidean' cestodes from the orectolobiform shark family Brachaeluridae Applegate. The association of the new species with orectolobiform sharks is consistent with those of the other members of Clade 3. However, whereas species of Carpobothrium and Caulopatera parasitise members of the hemiscylliid genus Chiloscyllium Müller et Henle, species of Amitalveolus gen. n. parasitise members of the Brachaeluridae and Orectolobidae Gill.

Recent examinations of some marine fishes from off the southern coast of Iraq revealed the presence of five species of Philometra Costa, 1845 (Nematoda: Philometridae): Philometra arabiensis sp. n. (males and females) from the ovary of the shrimp scad Alepes djedaba (Forsskål) (Carangidae, Carangiformes), Philometra psettoditis Moravec, Walter et Yuniar, 2012 (females) from the body cavity of the Indian halibut Psettodes erumei (Bloch et Schneider) (Psettodidae, Pleuronectiformes), Philometra terapontis Moravec, Gopalakrishnan, Rajkumar, Saravanakumar et Kaliyamoorthy, 2011 (female) from the ovary of the jarbua terapon Terapon jarbua (Forsskål) (Terapontidae, Centrarchiformes), Philometra sp. (females) from the ovary of the Arabian blackspot threadfin Polydactylus mullani (Hora) (Polynemidae, Carangariformes) and Philometra sp. 2 of Moravec et al. (2016a) (females) from the ovary and body cavity of the bartail flathead Platycephalus indicus (Linnaeus) (Platycephalidae, Perciformes). Philometra arabiensis sp. n. is mainly characterised by the length of spicules (198-243 µm) and gubernaculum (75-99 µm), the gubernaculum/spicule length ratio (1 : 2.33-2.79), the structure of the gubernaculum distal portion and the male caudal end, and the body length of males (1.86-2.73 mm). The present findings of P. psettoditis and P. terapontis in fishes of the Arabian Gulf represent new geographical records for these parasites.

Numerous recent studies show that vitamin D deficiency potentiates various chronic physical and psychiatric disorders and diseases. It has been shown that a similar range of disorders is also associated with latent infection with Toxoplasma gondii (Nicolle et Manceaux, 1908). For instance, among cancer, diabetes and schizophrenia patients, we find a higher prevalence of both toxoplasmosis and vitamin D deficiency. Theoretically, therefore, vitamin D deficiency could be the missing link between toxoplasmosis and these disorders. We tested this hypothesis by searching for decreased vitamin D levels in the serum of subjects infected with T. gondii (furthermore called Toxoplasma-infected subjects) in two cross-sectional and one case-control study. Results of the first cross-sectional study (N = 72) suggest that Toxoplasma-infected neurasthenic patients have non-significantly lower levels of calcidiol than Toxoplasma-free patients (study A: P = 0.26 in women, P = 0.68 in men). However, two other studies (study B: N = 400; study C: N = 191) showed a non-significantly higher concentration of vitamin D in Toxoplasma-infected subjects than in Toxoplasma-free subjects both in men (study B: P = 0.70, study C: P = 0.55) and in women (study B: P = 0.64, study C: P = 0.12). Taken together, our preliminary results thus do not support the hypothesis that toxoplasmosis could be associated with vitamin D decrease.

Specimens of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. are described from Schizothorax richardsonii (Gray) in the Poonch River, Jammu and Kashmir. Specimens are thick-walled with dissimilar dorsal and ventral para-receptacle structures, anteriorly manubriated hooks, two giant nuclei in each lemniscus and many subcutaneousy. The lemnisci barely overlap the larger anterior testis, the cement gland has eight giant nuclei, and the seminal vesicle is large with thin walls. The vagina is unremarkable but the long uterus is made up of four specialised regions. Neoechinorhynchus rigidus (Van Cleave, 1928), resembles N. poonchensis sp. n. It is distinguished from N. poonchensis sp. n. by having smaller trunk, proboscis, and male reproductive structures, equal testes, unequal lemnisci with three giant nuclei each, and much larger anterior proboscis hook (130 μm in males) than that originally described by Van Cleave (1928) (70 μm in a female). Anterior hook length alone is sufficient to conclude that the N. rigidus of Datta (1937) is not the same species as the N. rigidus of Van Cleave (1928). Van Cleave's (1928) species remains valid and that of Datta (1937) is considered a different species named Neoechinorhynchus pseudorigidus sp. n., herein. Micropores of N. poonchensis sp. n. have variable distribution in different trunk regions and the Energy Dispersive X-ray analysis demonstrated higher levels of sulfur and lower levels of calcium and phosphorus. Sequences of the 18S rDNA gene from nuclear DNA, and cytochrome c oxidase subunit I (cox1) from mitochondrial DNA of N. poonchensis sp. n. were amplified and aligned with other sequences available on GenBank. Maximum likelihood (ML) and Bayesian inference (BI) analyses inferred for 18S rDNA and cox1 showed that N. poonchensis sp. n. was nested in a separate clade.

Rhipicephalus camicasi Morel, Mouchet et Rodhain, 1976 is thought to be distributed across Africa, Arabian Peninsula and the Mediterranean region. It belongs to the Rhipicephalus sanguineus (Latreille, 1806) species complex. Mitochondrial genome sequences are becoming frequently used for the identification and differentiation of tick species. In the present study, the entire mitochondrial genome of R. cf. camicasi (~15 kb) collected from a camel in Saudi Arabia was sequenced and compared with mitogenomes of two species of Rhipicephalus Koch, 1844. The mitochondrial genome is 87.8% and 91.7% identical to the reference genome of R. sanguineus (sensu stricto, former "temperate lineage") and Rhipicephalus linnaei (Audouin, 1826) (former "tropical lineage"). The current study delivers a molecular reference for material that resembles R. camicasi. We propose to consider the current material, including the complete mitogenome, as the reference for R. camicasi, until a revision using topotypical material is available.

The nematodes Toxocara canis (Werner, 1782) and Toxocara cati (Schrank, 1788) have been associated with worse human cognitive function in children and middle-aged adults. In this study, we sought to determine the association between Toxocara seropositivity and serointensity determined by detection of IgG antibodies against the Toxocara antigen recombinant Tc-CTL-1 and cognitive function in older adults, including approximately 1,350 observations from the 2013-2014 National Health and Nutrition Examination Survey. Mean fluorescence intensity was used to quantify IgG antibodies against the Toxocara recombinant Tc-CTL-1 antigen, and respondents were considered positive at values greater than 23.1. In adjusted models from sample sizes ranging from 1,274 to 1,288 depending on the individual cognitive task, we found that Toxocara seropositivity was associated with worse performance on the animal-fluency task (b = -1.245, 95% CI: -2.392 to -0.099, P< 0.05) and the digit-symbol coding task (b = -5.159, 95% CI: -8.337 to -1.980, P< 0.001). Toxocara serointensity assessed using log-transformed mean fluorescence intensity as a continuous variable was associated with worse performance on the digit-symbol coding task (b = -1.880, 95% CI: -2.976 to -0.783, P < 0.001). There were no significant associations with tasks assessing memory. Further, age modified the association between Toxocara and cognitive function, although sex, educational attainment, and income did not. These findings suggest that Toxocara might be associated with deficits in executive function and processing speed in older U.S. adults, although additional research is required to better describe cognitive function in older adults who are seropositive for Toxocara spp.

Dactylogyrus Diesing, 1850 is the most species-rich genus in Platyhelminthes, with over 900 documented species, that are mostly strictly specific to freshwater cyprinoids. The morphological Dactylogyrus groups afrobarbae-type, carpathicus-type, pseudoanchoratus-type, and varicorhini-type are known to occur in Africa. This study describes a new species of Dactylogyrus of the varicorhini-type from the gills of the endemic smallmouth yellowfish Labeobarbus aeneus (Burchell) from the Vaal River, Free State Province, South Africa. Dactylogyrus matlopong sp. n. is unique among its varicorhini-type congeners mainly by the accessory piece of the male copulatory complex that presents a hook-shaped subunit with defined round base not reaching the male copulatory organ, combined with the presence of a conspicuous medial projection on the anterior margin of the ventral bar. Sequences of the partial 28S and 18S rRNA genes, together with entire ITS1 region, were generated for the first time for a species of Dactylogyrus from South Africa. Concatenated phylogenetic analyses of selected Dactylogyrus spp. showed that these parasites group according to their morphological types.