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PLoS Neglected Tropical Diseases Apr 2024Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income...
BACKGROUND
Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income countries, especially in school-aged children. Improved diagnostic methods, especially for light intensity infections, are needed for efficient, control and elimination of STHs as a public health problem, as well as STH management. Image-based artificial intelligence (AI) has shown promise for STH detection in digitized stool samples. However, the diagnostic accuracy of AI-based analysis of entire microscope slides, so called whole-slide images (WSI), has previously not been evaluated on a sample-level in primary healthcare settings in STH endemic countries.
METHODOLOGY/PRINCIPAL FINDINGS
Stool samples (n = 1,335) were collected during 2020 from children attending primary schools in Kwale County, Kenya, prepared according to the Kato-Katz method at a local primary healthcare laboratory and digitized with a portable whole-slide microscopy scanner and uploaded via mobile networks to a cloud environment. The digital samples of adequate quality (n = 1,180) were split into a training (n = 388) and test set (n = 792) and a deep-learning system (DLS) developed for detection of STHs. The DLS findings were compared with expert manual microscopy and additional visual assessment of the digital samples in slides with discordant results between the methods. Manual microscopy detected 15 (1.9%) Ascaris lumbricoides, 172 (21.7%) Tricuris trichiura and 140 (17.7%) hookworm (Ancylostoma duodenale or Necator americanus) infections in the test set. Importantly, more than 90% of all STH positive cases represented light intensity infections. With manual microscopy as the reference standard, the sensitivity of the DLS as the index test for detection of A. lumbricoides, T. trichiura and hookworm was 80%, 92% and 76%, respectively. The corresponding specificity was 98%, 90% and 95%. Notably, in 79 samples (10%) classified as negative by manual microscopy for a specific species, STH eggs were detected by the DLS and confirmed correct by visual inspection of the digital samples.
CONCLUSIONS/SIGNIFICANCE
Analysis of digitally scanned stool samples with the DLS provided high diagnostic accuracy for detection of STHs. Importantly, a substantial number of light intensity infections were missed by manual microscopy but detected by the DLS. Thus, analysis of WSIs with image-based AI may provide a future tool for improved detection of STHs in a primary healthcare setting, which in turn could facilitate monitoring and evaluation of control programs.
Topics: Child; Animals; Humans; Artificial Intelligence; Soil; Microscopy; Resource-Limited Settings; Feces; Trichuris; Helminthiasis; Helminths; Ascaris lumbricoides; Ancylostomatoidea; Prevalence
PubMed: 38602896
DOI: 10.1371/journal.pntd.0012041 -
Brazilian Journal of Veterinary Medicine 2024is considered the most common marsupial in Rio Grande do Sul. With omnivorous and synanthropic habits, it can serve as a host to various parasites, playing an important...
is considered the most common marsupial in Rio Grande do Sul. With omnivorous and synanthropic habits, it can serve as a host to various parasites, playing an important role in maintaining their biological cycle. Despite being a widespread and abundant species, it has a relatively little-known parasitic fauna. Therefore, the aim of this study was to report the diversity of parasites in a fecal sample from in Rio Grande do Sul, Southern Brazil. Modified Centrifugal-flotation and Spontaneous sedimentation techniques were used, revealing a high taxonomic diversity of parasites. Eggs of spp., spp., and Anoplocephalidae were reported for the first time in the host in the southern region of the country, along with the first report of pseudoparasitism by spp. and spp. in this animal species. The presence of different parasites in the feces of is of utmost importance, primarily for public health, but also for understanding the biodiversity of parasites present in wildlife, which has been poorly studied until now. This allows the implementation of effective strategies for controlling, preventing and treating these diseases.
PubMed: 38577262
DOI: 10.29374/2527-2179.bjvm000524 -
Medical Science Monitor : International... Mar 2024BACKGROUND Ancylostoma spp., including A. duodenale, A. braziliense, A. caninum, and A. ceylanicum, are hookworms that are transmitted from infected soil and by contact...
BACKGROUND Ancylostoma spp., including A. duodenale, A. braziliense, A. caninum, and A. ceylanicum, are hookworms that are transmitted from infected soil and by contact with domestic animals and rodent hosts, and can cause systemic disease and cutaneous larva migrans. The objective of this study was to describe the ecoepidemiology of Ancylostoma caninum and Ancylostoma spp. in urban-marginal sectors and in rural sectors located in Ecuador. MATERIAL AND METHODS Through addressed sampling, a total of 498 domestic dogs and 40 synanthropic rodents were analyzed via the following coproparasitic methods: direct, flotation, sedimentation with centrifugation using saline (egg identification), modified Baermann (larval identification), and morphometric methods (confirmation). A total of 236 people were surveyed, and a clinical analysis was performed via physical examination. The environmental variables were obtained through reports from the INAMHI of Ecuador and the use of online environmental programs. Through surveys, data related to social determinants were obtained. Epidemiological indicators (prevalence, morbidity, and mortality) were obtained through microbial analysis and surveys. RESULTS A total of 250 domestic dogs were diagnosed with Ancylostoma caninum (50, 20%), and 41 were diagnosed with Ancylostoma spp. (8.23%). One synanthropic rodent (2.5%) was positive for A. caninum. In the clinical analysis, 3 patients were identified as positive (1.27%) for cutaneous larva migrans (CLM). Likewise, environmental variables and social determinants influence the transmission, prevalence, and nature of parasitism by hookworm. CONCLUSIONS People, domestic dogs, and rodents were infected with these parasites. Consequently, there is a risk of ancylostomiasis and cutaneous larvae migrans spreading.
Topics: Humans; Animals; Dogs; Ancylostoma; Larva Migrans; Ecuador; Prevalence; Larva; Feces
PubMed: 38500436
DOI: 10.12659/MSM.943931 -
Veterinary Parasitology Jun 2024Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are...
Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments. Protection is associated with reduced cumulative faecal egg counts across the duration of the trials, relative to control animals. To better understand the diversity of antigens in O. ostertagi ES-thiol we used high-resolution shotgun proteomics to identify 490 unique proteins in the vaccine preparation. The most numerous ES-thiol proteins, with 91 proteins identified, belong to the sperm-coating protein/Tpx/antigen 5/pathogenesis-related protein 1 (SCP/TAPS) family. This family includes previously identified O. ostertagi vaccine antigens O. ostertagi ASP-1 and ASP-2. The ES-thiol fraction also has numerous proteinases, representing three distinct classes, including: metallo-; aspartyl- and cysteine proteinases. In terms of number of family members, the M12 astacin-like metalloproteinases, with 33 proteins, are the most abundant proteinase family in O. ostertagi ES-thiol. The O. ostertagi ES-thiol proteome provides a comprehensive database of proteins present in this vaccine preparation and will guide future vaccine antigen discovery projects.
Topics: Animals; Ostertagia; Vaccines; Antigens, Helminth; Ostertagiasis; Sulfhydryl Compounds; Feces; Proteomics; Parasite Egg Count
PubMed: 38490160
DOI: 10.1016/j.vetpar.2024.110154 -
Parasites, Hosts and Diseases Feb 2024Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and...
Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and iron-deficiency anemia. Helminth parasites secrete calreticulin (CRT), which regulates or blocks the host's immune response. However, no data on A. ceylanicum calreticulin (Ace-CRT) are available. We investigated the biological function of recombinant Ace-CRT (rAce-CRT). rAce-CRT showed reliable antigenicity and stimulated the proliferation of mouse splenocytes and canine peripheral blood mononuclear cells. Quantitative reverse-transcription PCR assays revealed that rAce-CRT primarily promoted the expression of T helper 2 cytokines, particularly IL-13, in canine peripheral blood lymphocytes. rAce-CRT inhibited complement-mediated sheep erythrocyte hemolysis in vitro. Our findings indicate that Ace-CRT plays an immunomodulatory role and may be a promising candidate molecule for a hookworm vaccine.
Topics: Humans; Animals; Dogs; Cats; Mice; Sheep; Ancylostoma; Calreticulin; Cat Diseases; Leukocytes, Mononuclear; Dog Diseases; Immunity
PubMed: 38443772
DOI: 10.3347/PHD.23108 -
Parasites & Vectors Mar 2024Soil-transmitted helminths (STH) infect more than a quarter of the world's human population. In the absence of vaccines for most animal and human gastrointestinal...
Phytochemical analysis and anthelmintic activity of Combretum mucronatum leaf extract against infective larvae of soil-transmitted helminths including ruminant gastrointestinal nematodes.
BACKGROUND
Soil-transmitted helminths (STH) infect more than a quarter of the world's human population. In the absence of vaccines for most animal and human gastrointestinal nematodes (GIN), treatment of infections primarily relies on anthelmintic drugs, while resistance is a growing threat. Therefore, there is a need to find alternatives to current anthelmintic drugs, especially those with novel modes of action. The present work aimed to study the composition and anthelmintic activity of Combretum mucronatum leaf extract (CMLE) by phytochemical analysis and larval migration inhibition assays, respectively.
METHODS
Combretum mucronatum leaves were defatted with petroleum ether and the residue was extracted by ethanol/water (1/1) followed by freeze-drying. The proanthocyanidins and flavonoids were characterized by thin layer chromatography (TLC) and ultra-high performance liquid chromatography (UPLC). To evaluate the inhibitory activity of this extract, larval migration assays with STH and GIN were performed. For this purpose, infective larvae of the helminths were, if necessary, exsheathed (Ancylostoma caninum, GIN) and incubated with different concentrations of CMLE.
RESULTS
CMLE was found to be rich in flavonoids and proanthocyanidins; catechin and epicatechin were therefore quantified for standardization of the extract. Data indicate that CMLE had a significant effect on larval migration. The effect was dose-dependent and higher concentrations (1000 µg/mL) exerted significantly higher larvicidal effect (P < 0.001) compared with the negative control (1% dimethyl sulfoxide, DMSO) and lower concentrations (≤ 100 µg/ml). Infective larvae of Ascaris suum [half-maximal inhibitory concentration (IC) = 5.5 µg/mL], Trichuris suis (IC = 7.4 µg/mL), and A. caninum (IC = 18.9 µg/mL) were more sensitive to CMLE than that of Toxocara canis (IC = 310.0 µg/mL), while infective larvae of Toxocara cati were largely unaffected (IC > 1000 µg/mL). Likewise, CMLE was active against most infective larvae of soil-transmitted ruminant GIN, except for Cooperia punctata. Trichostrongylus colubriformis was most sensitive to CMLE (IC = 2.1 µg/mL) followed by Cooperia oncophora (IC = 27.6 µg/mL), Ostertagia ostertagi (IC = 48.5 µg/mL), Trichostrongylus axei (IC = 54.7 µg/mL), Haemonchus contortus (IC = 145.6 µg/mL), and Cooperia curticei (IC = 156.6 µg/mL).
CONCLUSIONS
These results indicate that CMLE exhibits promising anthelmintic properties against infective larvae of a large variety of soil-transmitted nematodes.
Topics: Animals; Humans; Combretum; Proanthocyanidins; Larva; Plant Extracts; Nematoda; Anthelmintics; Helminths; Ruminants; Flavonoids; Trichostrongyloidea; Phytochemicals
PubMed: 38429804
DOI: 10.1186/s13071-024-06194-9 -
Indian Journal of Pathology &... Feb 2024Infections caused due to zoonotic hookworms are rare and are often under reported. Here we report a case of diarrheal disease caused by Ancylostoma ceylanicum, an...
Infections caused due to zoonotic hookworms are rare and are often under reported. Here we report a case of diarrheal disease caused by Ancylostoma ceylanicum, an important emerging zoonotic hookworm. There is limited knowledge about the epidemiology and disease burden of A. ceylanicum infections in Kerala. A 50-year-old male patient presented with complaints of loose stools for past five weeks. The laboratory investigations revealed a high total WBC count and eosinophil count. Diagnostic colonoscopy showed numerous worms which were identified as A. ceylanicum. Timely diagnosis aided in successful treatment of the patient. Improvement in diagnostic tools and awareness enable accurate and early detection of this neglected but emerging pathogen.
PubMed: 38427762
DOI: 10.4103/ijpm.ijpm_385_23 -
International Journal of Environmental... Jan 2024Zoonotic parasitic diseases in dogs are particularly concerning in regions with low human development indices due to inadequate sanitary services and insufficient...
Zoonotic parasitic diseases in dogs are particularly concerning in regions with low human development indices due to inadequate sanitary services and insufficient environmental and health education. This study aimed to assess the parasitological status of dogs living in households and evaluate their owners' knowledge about zoonoses. A total of 183 dogs from Rolim de Moura, Rondônia State, were screened for the presence of ectoparasites, and 163 fecal samples were collected for analysis. The results showed that 74.23% (112/163) of the animals had at least one species of endoparasite. The most identified pathogens were spp. (68.71%, 112/163), (11.66%, 19/163), (6.75%, 11/163), (4.91%, 8/163), (1.23%, 2/163), and (0.61%, 1/163). Ectoparasites were observed in 43.17% (79/183) of the evaluated animals, with found in 31.15% (57/183) and in 20.77% (38/183). Only 11.48% (7/61) of the owners were familiar with the term "Zoonoses." However, a significant majority (83.61%, 51/61) believed that dogs can transmit diseases to humans. Our findings highlight the prevalence of parasites in the studied area and associated risk factors, underscoring the urgent need for educational interventions to raise awareness about these diseases and their risks to human health.
Topics: Humans; Animals; Dogs; Intestinal Diseases, Parasitic; Zoonoses; Parasites; Ecosystem; Feces; Prevalence; Dog Diseases; Perception
PubMed: 38397629
DOI: 10.3390/ijerph21020138 -
Parasites & Vectors Feb 2024Nematodes of the Ascarididae, Ancylostomatidae and Onchocercidae families are parasites of human and veterinary importance causing infections with high prevalence...
BACKGROUND
Nematodes of the Ascarididae, Ancylostomatidae and Onchocercidae families are parasites of human and veterinary importance causing infections with high prevalence worldwide. Molecular tools have significantly improved the diagnosis of these helminthiases, but the selection of genetic markers for PCR or metabarcoding purposes is often challenging because of the resolution these may show.
METHODS
Nuclear 18S rRNA, internal transcribed spacers 1 (ITS-1) and 2 (ITS-2), mitochondrial gene cytochrome oxidase 1 (cox1) and mitochondrial rRNA genes 12S and 16S loci were studied for 30 species of the mentioned families. Accordingly, their phylogenetic interspecies resolution, pairwise nucleotide p-distances and sequence availability in GenBank were analyzed.
RESULTS
The 18S rRNA showed the least interspecies resolution since separate species of the Ascaris, Mansonella, Toxocara or Ancylostoma genus were intermixed in phylogenetic trees as opposed to the ITS-1, ITS-2, cox1, 12S and 16S loci. Moreover, pairwise nucleotide p-distances were significantly different in the 18S compared to the other loci, with an average of 99.1 ± 0.1%, 99.8 ± 0.1% and 98.8 ± 0.9% for the Ascarididae, Ancylostomatidae and Onchocercidae families, respectively. However, ITS-1 and ITS-2 average pairwise nucleotide p-distances in the three families ranged from 72.7% to 87.3%, and the cox1, 12S and 16S ranged from 86.4% to 90.4%. Additionally, 2491 cox1 sequences were retrieved from the 30 analyzed species in GenBank, whereas 212, 1082, 994, 428 and 143 sequences could be obtained from the 18S, ITS-1, ITS-2, 12S and 16S markers, respectively.
CONCLUSIONS
The use of the cox1 gene is recommended because of the high interspecies resolution and the large number of sequences available in databases. Importantly, confirmation of the identity of an unknown specimen should always be complemented with the careful morphological examination of worms and the analysis of other markers used for specific parasitic groups.
Topics: Humans; Animals; RNA, Ribosomal, 18S; Sarcocystis; Sarcocystosis; Phylogeny; Nematoda; Nucleotides
PubMed: 38378676
DOI: 10.1186/s13071-023-06113-4 -
International Journal For Parasitology.... Apr 2024Within the context of our anthelmintic discovery program, we recently identified and evaluated a quinoline derivative, called ABX464 or obefazimod, as a nematocidal...
Within the context of our anthelmintic discovery program, we recently identified and evaluated a quinoline derivative, called ABX464 or obefazimod, as a nematocidal candidate; synthesised a series of analogues which were assessed for activity against the free-living nematode Caenorhabditis elegans; and predicted compound-target relationships by thermal proteome profiling (TPP) and in silico docking. Here, we logically extended this work and critically evaluated the anthelmintic activity of ABX464 analogues on Haemonchus contortus (barber's pole worm) - a highly pathogenic nematode of ruminant livestock. First, we tested a series of 44 analogues on H. contortus (larvae and adults) to investigate the nematocidal pharmacophore of ABX464, and identified one compound with greater potency than the parent compound and showed moderate activity against a select number of other parasitic nematodes (including Ancylostoma, Heligmosomoides and Strongyloides species). Using TPP and in silico modelling studies, we predicted protein HCON_00074590 (a predicted aldo-keto reductase) as a target candidate for ABX464 in H. contortus. Future work aims to optimise this compound as a nematocidal candidate and investigate its pharmacokinetic properties. Overall, this study presents a first step toward the development of a new nematocide.
Topics: Animals; Antinematodal Agents; Nematoda; Anthelmintics; Haemonchus; Structure-Activity Relationship; Caenorhabditis elegans; Quinolines
PubMed: 38295619
DOI: 10.1016/j.ijpddr.2024.100522