Parasitology最新文献

Female genital schistosomiasis (FGS) is a neglected manifestation of Schistosoma haematobium infection, affecting an estimated 56 million women in sub-Saharan Africa. It is characterized by lesions in the genital tract, leading to symptoms like pain, infertility and an increased risk of HIV transmission. Despite its prevalence, FGS remains underdiagnosed and underreported due to limited awareness and diagnostic capabilities. Current knowledge emphasizes the need for integrated approaches combining diagnosis, treatment with praziquantel and education. There are ongoing efforts to integrate FGS services into women's sexual and reproductive services, yet to date many African countries lack programmatic guidance to achieve this. More comprehensive integration and mainstreaming of FGS prevention, control and treatment across various sectors is needed to ensure intersectoral collaboration and financing of programmes. This review examines the various intervention tools currently available to achieve FGS integration in health systems. These include water, sanitation and hygiene improvements, environmental management, health education and inclusion of preschool-aged children in national schistosomiasis control programmes. Highlighted are also the required diagnostic and therapeutic tools, preventive interventions, effective policy and sustainable funding, all integral to achieving comprehensive FGS mainstreaming.

Female genital schistosomiasis (FGS) is a chronically disabling gynaecological condition, impacting up to 56 million women and girls, mostly in sub-Saharan Africa. In lieu of a gold standard laboratory test, it is possible to diagnose FGS visually. Visual diagnosis is performed through inspection of the cervix and surrounding tissue to identify signs of Schistosoma egg deposition, associated inflammation and granuloma formation. The change related to egg deposition can be very subtle and heterogeneous and is often seen in the context of other altered cervical morphology. Visual diagnostics for FGS are therefore currently highly subjective and lack specificity, with low consistency of grading between trained expert reviewers. Computer vision, driven by artificial intelligence, is an enticing prospect to overcome these issues due to the potential to accurately detect and classify the subtle changes and patterns that are indiscernible to human graders. Computer vision also offers the opportunity to support resource-constrained regions with few staff trained on visual diagnostics. However, several challenges stand in the way of progressing and successfully implementing computer vision tools for FGS. These challenges are particularly related to the variation in the appearance of the cervix (with or without disease) and FGS lesions, as well as the difficulty with accurately labelling cervical images. Exploring alternative annotation methods and model architectures is likely to improve the performance of FGS computer vision tools. This paper will explore the challenges of FGS computer vision and provide suggestions on how to overcome these barriers to enhance visual diagnostics for FGS.

Schistosomiasis is a parasitic disease that imposes a significant burden on society. The eggs are the primary pathogenic factor in schistosomiasis, and their accumulation in liver could lead to the formation of granulomas and liver fibrosis. However, the metabolic changes in liver resulting from schistosomiasis remain poorly understood. We established a mouse model of schistosomiasis japonica, where the eggs accumulate in the liver and form egg granulomas. We used mass spectrometry imaging to analyze the differences in metabolites among various liver regions, including the liver tissue from normal mice, the liver area outside the granulomas in schistosomiasis mice, and the granuloma region in schistosomiasis mice. There were significant differences in metabolites between different liver regions, which enriched in metabolic pathways such as the biosynthesis of unsaturated fatty acids, taurine and hypotaurine metabolism, glycerophospholipid metabolism, glycolysis/gluconeogenesis, purine metabolism, arachidonic acid metabolism, and bile secretion. In normal liver tissue, higher concentrations of oleic acid (FA (18:1)), eicosapentaenoic acid (FA (20:5)), and L-glutamine were observed. In liver regions outside the granulomas, D-glucose and pyruvic acid were elevated compared to those in normal mice. Taurine increased in the liver of schistosomiasis. Meanwhile, there were elevated uric acid and spermidine in the egg granulomas. We employed mass spectrometry imaging technology to investigate metabolic reprogramming in liver of Schistosoma japonicum-infected mice. We explored the spatial distribution of differential metabolites in liver of schistosomiasis including unsaturated fatty acids, taurine, glutamine, spermidine, and uric acid. Our research provides valuable insights for further elucidating metabolic reprogramming in schistosomiasis.

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

Rosacea is a chronic inflammatory skin disease affecting approximately 5.4% of the world population. Among its pathogenic factors is infestation by Demodex spp. Standardized skin surface biopsy (SSSB) and direct microscopic examination (DME) are widely used methods to measure Demodex spp density (Dd); however, there is no agreement on the method of choice, nor the prevalence of infestation in rosacea patients. This study compared both techniques in rosacea patients. A prospective study was conducted with 61 patients diagnosed with rosacea by dermatologists from two dermatology centres. Dd was evaluated using SSSB and DME in each patient. Results, median sampling time and reported pain were analyzed using appropriate statistical methods. The median Dd was significantly higher with SSSB (11 mites/cm²) compared to DME (1 mites/cm²; P < 0.001). Infestation (>5 mites/cm²) was detected in 64% of patients with SSSB and in 28% with DME (P < 0.001). The median sampling time was longer for SSSB (60 s) than for DME (30 s; P < 0.001). Both methods were associated with mild pain, slightly lower with DME (P = 0.033). SSSB proved more effective than DME for detecting Demodex spp. in rosacea, identifying a greater total number of mites and a higher percentage of infestation. Up to 64% of rosacea patients showed infestation with Demodex spp. using the SSSB technique. The results reinforce the use of SSSB as the standard technique for diagnosing Demodex spp. infestation in rosacea patients.

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

Urogenital schistosomiasis (UGS) caused by zoonotic or hybrid schistosome infection(s) is an emerging public health concern in Malawi, and we describe a 1-year clinical sub-study with 3 inspection time points for female genital schistosomiasis (FGS) upon selecting 86 women with proven UGS. This sub-study was set within a broader 2-year longitudinal 'Hybridization in UroGenital Schistosomiasis (HUGS)' investigation. A detailed cervicovaginal examination with a portable colposcope was conducted, examining cervicovaginal lavage (CVL), cervical swab, cervical biopsy and urine with traditional parasitological and molecular diagnostic methods. At baseline, overt FGS by colposcopy was 72.1%, 64.3% by CVL real-time PCR and 51.2% by both colposcopy and CVL-PCR, noting urine-microscopy could often be negative. Human papillomavirus was detected in 31.0% of the cervical swabs, with 8.3% women also FGS positive by colposcopy and real-time PCR. Over the year, FGS prevalence by colposcopy increased by 32.7% during the study to 84.6%, homogenous yellow and grainy sandy patches being very common in the youngest 18-25 age group, where 51.9% were positive. FGS appears widespread locally and we discuss difficulties in its detection without invasive sampling. In addition to the presence of S. haematobium, S. mattheei was noted alongside key concurrent sexually transmitted infections. From our findings, we point out that improved prevention and management of FGS is required, foremost, better availability and regular accessibility to praziquantel treatment is needed. Furthermore, targeted health education, raised community awareness and dovetailing synergistic public health activities within Sexual and Reproductive Health services and local HIV/AIDS programmes could develop an appropriate holistic health intervention package.

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

Hookworms are common parasites of Eurasian badgers (Meles meles), typically identified as Uncinaria criniformis. The taxonomic distinction from Uncinaria stenocephala, a species found in dogs and foxes, has long been debated. In this study, we molecularly characterized U. criniformis from a Eurasian badger in Romania using genome skimming. We assembled the complete mitochondrial genome and internal transcribed spacer (ITS) rDNA region from 2 adult hookworms morphologically consistent with U. criniformis. Phylogenetic analysis of 12 mitochondrial protein-coding genes demonstrated strongly supported clade of U. criniformis with Ancylostoma spp. ITS rDNA and cox1 sequence comparisons revealed only 92.4-92.8% and 88.0-88.5% identity, respectively, between U. criniformis and U. stenocephala, confirming their molecular distinctiveness. In contrast, our sequences showed >99% identity to sequences from Arthrostoma leucurus, a hookworm recently described from the Asian badger (Meles leucurus), suggesting conspecificity. These findings support the validity of U. criniformis as a distinct species parasitizing M. meles, and we propose A. leucurus as a junior synonym of U. criniformis. Our results highlight the polyphyly of the genus Uncinaria and point to the need for broader mitogenomic sampling of hookworms. The molecular markers generated here provide a reference for future parasitological surveys and wildlife disease studies.