International journal for parasitology最新文献

{"title":"DNA metabarcoding reveals spatial and temporal variation of fish eye fluke communities in lake ecosystems","authors":"Alfonso Diaz-Suarez ,&nbsp;Kristina Noreikiene ,&nbsp;Siim Kahar ,&nbsp;Mikhail Y. Ozerov ,&nbsp;Riho Gross ,&nbsp;Veljo Kisand ,&nbsp;Anti Vasemägi","doi":"10.1016/j.ijpara.2023.07.005","DOIUrl":"10.1016/j.ijpara.2023.07.005","url":null,"abstract":"<div><p>Eye flukes (Diplostomidae) are diverse and abundant trematode parasites that form multi-species communities in fish with negative effects on host fitness and survival. However, the environmental factors and host-related characteristics that determine species diversity, composition, and coexistence in such communities remain poorly understood. Here, we developed a cost-effective <em>cox1</em> region-specific DNA metabarcoding approach to characterize parasitic diplostomid communities in two common fish species (Eurasian perch and common roach) collected from seven temperate lakes in Estonia. We found considerable inter- and intra-lake, as well as inter-host species, variation in diplostomid communities. Sympatric host species characterization revealed that parasite communities were typically more diverse in roach than perch. Additionally, we detected five positive and two negative diplostomid species associations in roach, whereas only a single negative association was observed in perch. These results indicate that diplostomid communities in temperate lakes are complex and dynamic systems exhibiting both spatial and temporal heterogeneity. They are influenced by various environmental factors and by host-parasite and inter-parasite interactions. We expect that the described methodology facilitates ecological and biodiversity research of diplostomid parasites. It is also adaptable to other parasite groups where it could serve to improve current understanding of diversity, distribution, and interspecies interactions of other understudied taxa.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 1","pages":"Pages 33-46"},"PeriodicalIF":4.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10577176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A mixed amplicon metabarcoding and sequencing approach for surveillance of drug resistance to levamisole and benzimidazole in Haemonchus spp.","authors":"Emily Kate Francis ,&nbsp;Alistair Antonopoulos ,&nbsp;Mark Edward Westman ,&nbsp;Janina McKay-Demeler ,&nbsp;Roz Laing ,&nbsp;Jan Šlapeta","doi":"10.1016/j.ijpara.2023.07.002","DOIUrl":"10.1016/j.ijpara.2023.07.002","url":null,"abstract":"<div><p>Anthelmintic-resistant parasitic nematodes present a significant threat to sustainable livestock production worldwide. The ability to detect the emergence of anthelmintic resistance at an early stage, and therefore determine which drugs remain most effective, is crucial for minimising production losses. Despite many years of research into the molecular basis of anthelmintic resistance, no molecular-based tools are commercially available for the diagnosis of resistance as it emerges in field settings. We describe a mixed deep amplicon sequencing approach to determine the frequency of the levamisole (LEV)-resistant single nucleotide polymorphism (SNP) within <em>arc</em>-8 exon 4 (S168T) in <em>Haemonchus</em> spp., coupled with benzimidazole (BZ)-resistant SNPs within <span><math><mrow><mi>β</mi></mrow></math></span><em>-tubulin</em> isotype-1 and the internal transcribed spacer-2 (ITS-2) nemabiome. This constitutes the first known multi-drug and multi-species molecular diagnostic developed for helminths of veterinary importance. Of the ovine, bovine, caprine and camelid Australian field isolates we tested, S168T was detected in the majority of <em>Haemonchus</em> spp. populations from sheep and goats, but rarely at a frequency greater than 16%; an arbitrary threshold we set based on whole genome sequencing (WGS) of LEV-resistant <em>Haemonchus contortus</em> GWBII. Overall, BZ resistance was far more prevalent in <em>Haemonchus</em> spp. than LEV resistance, confirming that LEV is still an effective anthelmintic class for small ruminants in New South Wales, Australia. The mixed amplicon metabarcoding approach described herein paves the way towards the use of large scale sequencing as a surveillance technology in the field, the results of which can be translated into evidence-based recommendations for the livestock sector.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 1","pages":"Pages 55-64"},"PeriodicalIF":4.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020751923001704/pdfft?md5=6e0ad332aa00d621f1ed0922410170dd&pid=1-s2.0-S0020751923001704-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9981430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of a serum ELISA test for cyathostomin infection in equines","authors":"Kirsty L. Lightbody ,&nbsp;Andrew Austin ,&nbsp;Peter A. Lambert ,&nbsp;Georg von Samson-Himmelstjerna ,&nbsp;Laura Jürgenschellert ,&nbsp;Jürgen Krücken ,&nbsp;Martin K. Nielsen ,&nbsp;Guillaume Sallé ,&nbsp;Fabrice Reigner ,&nbsp;Callum G Donnelly ,&nbsp;Carrie J. Finno ,&nbsp;Nicola Walshe ,&nbsp;Grace Mulcahy ,&nbsp;Nicola Housby-Skeggs ,&nbsp;Steven Grice ,&nbsp;Kathrin K. Geyer ,&nbsp;Corrine J. Austin ,&nbsp;Jacqueline B. Matthews","doi":"10.1016/j.ijpara.2023.07.001","DOIUrl":"10.1016/j.ijpara.2023.07.001","url":null,"abstract":"<div><p>Cyathostomins are ubiquitous equine nematodes. Infection can result in larval cyathostominosis due to mass larval emergence. Although faecal egg count (FEC) tests provide estimates of egg shedding, these correlate poorly with burden and provide no information on mucosal/luminal larvae. Previous studies describe a serum IgG(T)-based ELISA (CT3) that exhibits utility for detection of mucosal/luminal cyathostomins. Here, this ELISA is optimised/validated for commercial application using sera from horses for which burden data were available. Optimisation included addition of total IgG-based calibrators to provide standard curves for quantification of antigen-specific IgG(T) used to generate a CT3-specific ‘serum score’ for each horse. Validation dataset results were then used to assess the optimised test’s performance and select serum score cut-off values for diagnosis of burdens above 1000, 5000 and 10,000 cyathostomins. The test demonstrated excellent performance (Receiver Operating Characteristic Area Under the Curve values &gt;0.9) in diagnosing infection, with &gt;90% sensitivity and &gt;70% specificity at the selected serum score cut-off values. CT3-specific serum IgG(T) profiles in equines in different settings were assessed to provide information for commercial test use. These studies demonstrated maternal transfer of CT3-specific IgG(T) in colostrum to newborns, levels of which declined before increasing as foals consumed contaminated pasture. Studies in geographically distinct populations demonstrated that the proportion of horses that reported as test positive at a 14.37 CT3 serum score (1000-cyathostomin threshold) was associated with parasite transmission risk. Based on the results, inclusion criteria for commercial use were developed. Logistic regression models were developed to predict probabilities that burdens of individuals are above defined thresholds based on the reported serum score. The models performed at a similar level to the serum score cut-off approach. In conclusion, the CT3 test provides an option for veterinarians to obtain evidence of low cyathostomin burdens that do not require anthelmintic treatment and to support diagnosis of infection.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 1","pages":"Pages 23-32"},"PeriodicalIF":4.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020751923001698/pdfft?md5=8fa58a773f3654029dd06a1e07a14356&pid=1-s2.0-S0020751923001698-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9987010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-infecting Haemoproteus species (Haemosporida, Apicomplexa) show different host tissue tropism during exo-erythrocytic development in Fringilla coelebs (Fringillidae)","authors":"Tanja Himmel ,&nbsp;Josef Harl ,&nbsp;Julia Matt ,&nbsp;Nora Nedorost ,&nbsp;Madeleine Lunardi ,&nbsp;Mikas Ilgūnas ,&nbsp;Tatjana Iezhova ,&nbsp;Gediminas Valkiūnas ,&nbsp;Herbert Weissenböck","doi":"10.1016/j.ijpara.2023.07.004","DOIUrl":"10.1016/j.ijpara.2023.07.004","url":null,"abstract":"<div><p>Avian haemosporidians of the genera <em>Plasmodium</em>, <em>Haemoproteus,</em> and <em>Leucocytozoon</em> are common blood parasites in wild birds all over the world. Despite their importance as pathogens potentially compromising host fitness and health, little is known about the exo-erythrocytic development of these parasites, particularly during co-infections which predominate in wildlife. This study aimed to address this issue using <em>Haemoproteus</em> parasites of <em>Fringilla coelebs</em>, a common bird species of the Western Palearctic and host to a variety of haemosporidian parasite lineages. Blood and tissue samples of 20 <em>F. coelebs,</em> positive for haemosporidians by blood film microscopy, were analysed by PCR and sequencing to determine cytochrome b lineages of the parasites. Tissue sections were examined for exo-erythrocytic stages by histology and in situ hybridization applying genus-, species-, and lineage-specific probes which target the 18S rRNA of the parasites. In addition, laser microdissection of tissue stages was performed to identify parasite lineages. Combined molecular results of PCR, laser microdissection, and in situ hybridization showed a high rate of co-infections, with <em>Haemoproteus</em> lineages dominating. Exo-erythrocytic meronts of five <em>Haemoproteus</em> spp. were described for the first known time, including <em>Haemoproteus magnus</em> hCCF6<em>, Haemoproteus fringillae</em> hCCF3, <em>Haemoproteus majoris</em> hCCF5, <em>Haemoproteus</em> sp. hROFI1, and <em>Haemoproteus</em> sp. hCCF2. Merogonic stages were observed in the vascular system, presenting a formerly unknown mode of exo-erythrocytic development in <em>Haemoproteus</em> parasites. Meronts and megalomeronts of these species were distinct regarding their morphology and organ distribution, indicating species-specific patterns of merogony and different host tissue tropism. New pathological aspects of haemoproteosis were reported. Furthermore, phylogenetic analysis of <em>Haemoproteus</em> spp. with regard to their exo-erythrocytic stages points towards separation of non-megalomeront-forming species from megalomeront-forming species, calling for further studies on exo-erythrocytic development of haemosporidian parasites to explore the phylogenetic character of this trait.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 1","pages":"Pages 1-22"},"PeriodicalIF":4.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020751923001728/pdfft?md5=db46a07ddf6398789cc967ff134c2357&pid=1-s2.0-S0020751923001728-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10499813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid, automated quantification of Haemonchus contortus ova in sheep faecal samples","authors":"Jennifer L. Cain ,&nbsp;Leonor Sicalo Gianechini ,&nbsp;Abigail L. Vetter ,&nbsp;Sarah M. Davis ,&nbsp;Leah N. Britton ,&nbsp;Jennifer L. Myka ,&nbsp;Paul Slusarewicz","doi":"10.1016/j.ijpara.2023.07.003","DOIUrl":"10.1016/j.ijpara.2023.07.003","url":null,"abstract":"<div><p><em>Haemonchus contortus</em> is one of the most pathogenic nematodes affecting small ruminants globally and is responsible for large economic losses in the sheep and goat industry. Anthelmintic resistance is rampant in this parasite and thus parasite control programs must account for drug efficacy on individual farms and, sometimes, whether <em>H. contortus</em> is the most prevalent trichostrongylid. Historically, coproculture has been the main way to determine the prevalence of <em>H. contortus</em> in faecal samples due to the inability to morphologically differentiate between trichostrongylid egg types, but this process requires a skilled technician and takes multiple days to complete. Fluoresceinated peanut agglutinin (PNA) has been shown to specifically bind <em>H. contortus</em> and thus differentiate eggs based on whether they fluoresce, but this method has not been widely adopted. The Parasight^TM System (PS) fluorescently stains helminth eggs in order to identify and quantify them, and the <em>H. contortus</em> PNA staining method was therefore adapted to this platform using methodology requiring only 20 min to obtain results. In this study, 74 fecal samples were collected from sheep and analyzed for PNA-stained <em>H. contortus,</em> using both PS and manual fluorescence microscopy. The percentage of <em>H. contortus</em> was determined based on standard total strongylid counts with PS or brightfield microscopy. Additionally, 15 samples were processed for coproculture with larval identification, and analyzed with both manual and automated PNA methods. All methods were compared using the coefficient of determination (R²) and the Lin’s concordance correlation coefficient (ρc). Parasight^TM and manual PNA percent <em>H. contortus</em> results were highly correlated with R² = 0.8436 and ρc = 0.9100 for all 74 fecal samples. Coproculture versus PS percent <em>H. contortus</em> were also highly correlated with R² = 0.8245 and ρc = 0.8605. Overall, this system provides a rapid and convenient method for determining the percentage of <em>H. contortus</em> in sheep and goat fecal samples without requiring specialized training.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 1","pages":"Pages 47-53"},"PeriodicalIF":4.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10077296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parasite exchange and hybridisation at a wild-feral-domestic interface","authors":"William J. Smith ,&nbsp;Michał T. Jezierski ,&nbsp;Jenny C. Dunn ,&nbsp;Sonya M. Clegg","doi":"10.1016/j.ijpara.2023.06.005","DOIUrl":"10.1016/j.ijpara.2023.06.005","url":null,"abstract":"<div><p>Interactions between wild, feral, and domestic animals are of economic and conservation significance. The pigeon <em>Columba livia</em> is a synanthropic species in a feral form, but it also includes the rare Rock Dove. <em>Columba livia</em> is an important player at the wild-domestic interface, acting as a carrier of avian diseases, and the feral form threatens Rock Doves with extinction via hybridisation. Despite its abundance, little is known about drivers of disease prevalence in <em>C. livia</em>, or how disease and hybridisation represent synergistic threats to Rock Doves. We focused on infection by the parasite <em>Trichomonas</em>, first collating prevalence estimates in domestic and free-living populations from relevant studies of <em>C. livia</em>. Second, we characterised variation in the diversity and prevalence of <em>Trichomonas</em> among three <em>C. livia</em> populations in the United Kingdom: a feral, a Rock Dove, and a feral-wild hybrid population. Across multiple continents, free-living pigeons had lower <em>Trichomonas</em> infection than captive conspecifics, but the effect was weak. Environmental factors which could impact <em>Trichomonas</em> infection status did not explain variation in infection among populations. Among the British populations, strain diversity varied, and there was lower parasite prevalence in Rock Doves than feral pigeons. Individual infection status was not explained by the available covariates, including hybrid score and site. The drivers of <em>Trichomonas</em> prevalence are unclear, perhaps due to idiosyncratic local-scale drivers. However, given the population-level variation in both infection prevalence and introgressive hybridisation, the potential combined effects could accelerate the extinction of the Rock Dove. Further study of the synergistic effects of multiple types of biotic interactions at the wild-feral-domestic interface is warranted, especially where vagile, globally distributed and superabundant animals are involved.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"53 14","pages":"Pages 797-808"},"PeriodicalIF":4.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020751923001558/pdfft?md5=29bb4e5e8fa24b94e9f4466b5333061a&pid=1-s2.0-S0020751923001558-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9885922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The same genotype of Sarcocystis neurona responsible for mass mortality in marine mammals induced a clinical outbreak in raccoons (Procyon lotor) 10 years later","authors":"Aditya Gupta ,&nbsp;Mary Duncan ,&nbsp;Amy R. Sweeny ,&nbsp;Larissa S. de Araujo ,&nbsp;Oliver C.H. Kwok ,&nbsp;Benjamin M. Rosenthal ,&nbsp;Asis Khan ,&nbsp;Michael E. Grigg ,&nbsp;Jitender P. Dubey","doi":"10.1016/j.ijpara.2023.08.001","DOIUrl":"10.1016/j.ijpara.2023.08.001","url":null,"abstract":"<div><p>Here, we report the first known outbreak of clinical protozoal myeloencephalitis in naturally infected raccoons by the parasite <em>Sarcocystis neurona</em>. The North American opossum (<em>Didelphis virginiana</em>) and the South American opossum (<em>Didelphis albiventris</em>) are its known definitive hosts. Several other animal species are its intermediate or aberrant hosts. The raccoon (<em>Procyon lotor</em>) is considered the most important intermediate host for <em>S. neurona</em> in the USA. More than 50% of raccoons in the USA have sarcocysts in their muscles, however clinical sarcocystosis in raccoons is rare. In 2014, 38 free-living raccoons were found dead or moribund on the grounds of the Saint Louis Zoo, Missouri, USA. Moribund individuals were weak, lethargic, and mildly ataxic; several with oculo-nasal discharge. Seven raccoons were found dead and 31 were humanely euthanized. Postmortem examinations were conducted on nine raccoons. Neural lesions compatible with acute sarcocystosis were detected in eight raccoons. The predominant lesions were meningoencephalitis and perivascular mononuclear cells. Histologic evidence for the Canine Distemper Virus was found in one raccoon. Schizonts and merozoites were present in the encephalitic lesions of four raccoons. Mature sarcocysts were present within myocytes of five raccoons. In six raccoons, <em>S. neurona</em> schizonts and merozoites were confirmed by immunohistochemical staining with <em>S. neurona</em>-specific polyclonal antibodies. Viable <em>S. neurona</em> was isolated from the brains of two raccoons by bioassay in interferon gamma gene knockout mice and in cell cultures seeded directly with raccoon brain homogenate. Molecular characterization was based on raccoon no. 68. Molecular characterization based on multi-locus typing at five surface antigens (<em>SnSAG1-5</em>-<em>6, SnSAG3</em> and <em>SnSAG4</em>) and the <em>ITS-1</em> marker within the ssrRNA locus, using DNA isolated from bradyzoites released from sarcocysts in a naturally infected raccoon (no. 68), confirmed the presence of <em>S. neurona</em> antigen type I, the same genotype that caused a mass mortality event in which 40 southern sea otters stranded dead or dying within a 3 week period in April 2004 with <em>S. neurona</em>-associated disease. An expanded set of genotyping markers was next applied. This study reports the following new genotyping markers at 18S rRNA, 28S rRNA, <em>COX1</em>, <em>ITS-1</em>, <em>RON1</em>, <em>RON2</em>, <em>GAPDH1</em>, <em>ROP20</em>, <em>SAG2</em>, <em>SnSRS21</em> and <em>TUBA1</em> markers<em>.</em> The identity of <em>Sarcocystis</em> spp. infecting raccoons is discussed.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"53 14","pages":"Pages 777-785"},"PeriodicalIF":4.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10548144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bird species with wider geographical ranges have higher blood parasite diversity but not prevalence across the African-Eurasian flyway","authors":"Mary La Chapelle,&nbsp;Marcello Ruta,&nbsp;Jenny C. Dunn","doi":"10.1016/j.ijpara.2023.06.002","DOIUrl":"10.1016/j.ijpara.2023.06.002","url":null,"abstract":"<div><p>Avian blood parasites, from the genera <em>Plasmodium, Haemoproteus</em> and <em>Leucocytozoon</em>, are predicted to alter their range and prevalence as global temperatures change, and host and vector ranges shift. Understanding large-scale patterns in the prevalence and diversity of avian malaria and malaria-like parasites is important due to an incomplete understanding of their effects in the wild, where studies suggest even light parasitaemia can potentially cause rapid mortality, especially in naïve populations. We conducted phylogenetically controlled analyses to test for differences in prevalence and lineage diversity of haemoparasite infection (for <em>Plasmodium</em>, <em>Haemoproteus</em> and <em>Leucocytozoon</em>) in and between resident and migratory species along the African-Eurasian flyway. To test whether migratory strategy or range size drives differences in parasite prevalence and diversity between resident and migrant species, we included three categories of resident species: Eurasian only (<em>n</em> = 36 species), African only (<em>n</em> = 41), and species resident on both continents (<em>n</em> = 17), alongside intercontinental migrants (<em>n</em> = 64), using a subset of data from the MalAvi database comprising 27,861 individual birds. We found that species resident on both continents had a higher overall parasite diversity than all other categories. Eurasian residents had lower <em>Plasmodium</em> diversity than all other groups, and both migrants and species resident on both continents had higher <em>Haemoproteus</em> diversity than both African and Eurasian residents. <em>Leucocytozoon</em> diversity did not differ between groups. Prevalence patterns were less clear, with marked differences between genera. Both <em>Plasmodium</em> and <em>Leucocytozoon</em> prevalence was higher in species resident on both continents and African residents than in migrants and Eurasian residents. <em>Haemoproteus</em> prevalence was lower in Eurasian residents than species resident on both continents. Our findings contrast with previous findings in the North-South American flyway, where long-distance migrants had higher parasite diversity than residents and short-distance migrants, although we found contrasting patterns for parasite diversity to those seen for parasite prevalence. Crucially, our results suggest that geographic range may be more important than migratory strategy in driving parasite diversity within species along the African-Palaearctic flyway. Our findings differ between the three parasite genera included in our analysis, suggesting that vector ecology may be important in determining these large-scale patterns. Our results add to our understanding of global patterns in parasite diversity and abundance, and highlight the need to better understand the influence of vector ecology to understand the drivers of infection risk and predict responses to environmental change.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"53 14","pages":"Pages 787-796"},"PeriodicalIF":4.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020751923001522/pdfft?md5=4502f760ce88a522366f6dba7589111b&pid=1-s2.0-S0020751923001522-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9924348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interrelationships and properties of parasite aggregation measures: a user’s guide","authors":"A. Morrill ,&nbsp;R. Poulin ,&nbsp;M.R. Forbes","doi":"10.1016/j.ijpara.2023.06.004","DOIUrl":"10.1016/j.ijpara.2023.06.004","url":null,"abstract":"<div><p>Aggregation of macroparasites among hosts is nearly universal among parasite-host associations. Researchers testing hypotheses on origins of parasite aggregation and its importance to parasite and host population ecology have used different measures of aggregation that are not necessarily measuring the same thing, potentially clouding our understanding of underlying epidemiological processes. We highlight these differences in meanings by exploring properties and interrelationships of six common measures of parasite aggregation, and provide a “user’s guide” to inform researchers’ decisions regarding their application. We compared the mathematical expressions of the different measures of aggregation, and ran two series of simulations and analyses. The first simulations tested the effect of random removals of parasites on aggregation levels under different conditions, while the second explored interrelationships between the measures, as well as between other individual parasitological sample measures (i.e. mean abundance, prevalence) and aggregation. Results of simulations and analyses showed that the six measures of aggregation could be separated readily into three groups: the variance-to-mean ratio (VMR) together with mean crowding, patchiness with <em>k</em> of the negative binomial, and Poulin’s <em>D</em> with Hoover’s index. These three pairs of measures showed differing responses to random parasite removals and differing relations with mean abundance and/or prevalence, highlighting that metrics capture different variation in other sample measures and different attributes of aggregation. We used results of our simulations and analyses, and a literature review, to list the properties, advantages, and disadvantages of each aggregation metric. We provide a comprehensive exploration of what is assessed by each metric, as a guide to metric choice. We implore researchers to provide enough information such that aggregation measures from each group are reported or can be readily calculated. Such steps are needed to allow large-scale analyses of variation in degrees of aggregation within and among parasite-host associations, to uncover epidemiological processes shaping parasite distributions.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"53 14","pages":"Pages 763-776"},"PeriodicalIF":4.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10234070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ticks (Acari: Ixodida) on synanthropic small and medium-sized mammals in areas of the northeastern United States infested with the Asian longhorned tick, Haemaphysalis longicornis","authors":"Francisco C. Ferreira ,&nbsp;Julia González ,&nbsp;Matthew T. Milholland ,&nbsp;Grayson A. Tung ,&nbsp;Dina M. Fonseca","doi":"10.1016/j.ijpara.2023.06.003","DOIUrl":"10.1016/j.ijpara.2023.06.003","url":null,"abstract":"<div><p>The northeastern United States (US) is a hotspot for tick-borne diseases. Adding to an already complex vector landscape, in 2017 large populations of the invasive <em>Haemaphysalis longicornis</em>, the Asian longhorned tick, were detected in New Jersey (NJ) and later found to be widespread from Connecticut to Georgia<em>.</em> In its native range in northeastern Asia, <em>H. longicornis</em> is considered an important vector of deadly pathogens to humans, companion animals, and livestock. To identify the primary hosts of <em>H. longicornis,</em> we surveyed synanthropic small and medium-sized mammals in three different sites in suburban New Brunswick, NJ. Specifically, we collected approximately 9,000 tick specimens belonging to nine species from 11 different species of mammals sampled between May and September 2021. We found that <em>H. longicornis</em> feeds more frequently on rodents than previously thought, and that this invasive tick is likely exposed to important enzootic and zoonotic pathogens. Overall, we obtained detailed information about the seasonal dynamics and feeding patterns of six tick species common in the northeastern US, <em>Haemaphysalis longicornis</em>, <em>Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, Ixodes texanus</em> and <em>Ixodes cookei</em>. We found that unlike <em>I. scapularis</em> that feeds on mammals of all sizes, <em>H. longicornis</em> feeds on hosts following the general pattern of <em>A. americanum</em>, favoring larger species such as skunks, groundhogs, and raccoons. However, our survey revealed that unlike <em>A. americanum</em>, <em>H. longicornis</em> reaches high densities on Virginia opossum. Overall, the newly invasive <em>H. longicornis</em> was the most numerous tick species, both on multiple host species and in the environment, raising significant questions regarding its role in the epidemiology of tick-borne pathogens, especially those affecting livestock, companion animals and wildlife. In conclusion, our findings provide valuable insights into the tick species composition on mammalian hosts in NJ and the ongoing national expansion of <em>H. longicornis</em>.</p></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"53 14","pages":"Pages 809-819"},"PeriodicalIF":4.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10234071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}