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Acta Tropica May 2017It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of... (Review)
Review
It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of the world. The roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), and hookworms (Ancylostoma duodenale and Necator americanus) are the main species infecting people. These infections are mostly gained through exposure to faecally contaminated water, soil or contaminated food and with an increase in the risk of infections due to wastewater and sludge reuse in agriculture. Different methods have been developed for the detection and quantification of STHs eggs in environmental samples. However, there is a lack of a universally accepted technique which creates a challenge for comparative assessments of helminths egg concentrations both in different samples matrices as well as between locations. This review presents a comparison of reported methodologies for the detection of STHs eggs, an assessment of the relative performance of available detection methods and a discussion of new emerging techniques that could be applied for detection and quantification. It is based on a literature search using PubMed and Science Direct considering all geographical locations. Original research articles were selected based on their methodology and results sections. Methods reported in these articles were grouped into conventional, molecular and emerging techniques, the main steps in each method were then compared and discussed. The inclusion of a dissociation step aimed at detaching helminth eggs from particulate matter was found to improve the recovery of eggs. Additionally the selection and application of flotation solutions that take into account the relative densities of the eggs of different species of STHs also results in higher egg recovery. Generally the use of conventional methods was shown to be laborious and time consuming and prone to human error. The alternate use of nucleic acid-based techniques has improved the sensitivity of detection and made species specific identification possible. However, these nucleic acid based methods are expensive and less suitable in regions with limited resources and skill. The loop mediated isothermal amplification method shows promise for application in these settings due to its simplicity and use of basic equipment. In addition, the development of imaging soft-ware for the detection and quantification of STHs shows promise to further reduce human error associated with the analysis of environmental samples. It may be concluded that there is a need to comparatively assess the performance of different methods to determine their applicability in different settings as well as for use with different sample matrices (wastewater, sludge, compost, soil, vegetables etc.).
Topics: Ancylostoma; Animals; Ascaris lumbricoides; Feces; Helminthiasis; Helminths; Humans; Necator americanus; Soil; Trichuris; Wastewater
PubMed: 28214519
DOI: 10.1016/j.actatropica.2017.02.014 -
Parasitology Jul 2023Canine soil-transmitted helminths (STHs) cause important zoonoses in the tropics, with varying degrees of intensity of infection in humans and dogs. This study aimed to...
Canine soil-transmitted helminths (STHs) cause important zoonoses in the tropics, with varying degrees of intensity of infection in humans and dogs. This study aimed to investigate the prevalence and associated risk factors for STHs in community dogs residing in Grenada, West Indies. In May 2021, 232 canine fecal samples were examined for zoonotic helminths by microscopy (following flotation), and genomic DNA from a subset of 211 of these samples were subjected to multiplex qPCR for the detection and specific identification of hookworms, spp. and . Microscopic examination revealed that 46.5% (108/232, 95% CI 40–52.9), 9% (21/232, 95% CI 5.35–12.7) and 5.2% (12/232, 95% CI 2.3–8) of the samples contained eggs of spp., spp. and , respectively. Multiplex qPCR revealed that, 42.2% (89/211, 95% CI 35.5–48.8) were positive for at least 1 zoonotic parasite. Of these, 40.8% (86/211, 95% CI 34.1–47.3) of samples tested positive for spp., 36% (76/211, 95% CI 29.5–42.9) were positive for 13.3% (28/211, 95% CI 9–18.6) for , 5.7% for (12/211, 95% CI 2.97–8.81) and 1% (2/211, 95% CI 0–2.26) for spp. (identified as and by conventional PCR-based Sanger sequencing). Using a multiple logistic regression model, a low body score and free-roaming behaviour were significant predictors of test-positivity for these parasitic nematodes in dogs ( < 0.05). Further studies of zoonotic STHs in humans should help elucidate the public health relevance of these parasites in Grenada.
Topics: Animals; Dogs; Humans; Ancylostoma; Dog Diseases; Feces; Grenada; Helminths; Prevalence; Risk Factors; Toxocara; Zoonoses
PubMed: 37184089
DOI: 10.1017/S0031182023000495 -
Journal of Parasitic Diseases :... Dec 2015Despite an important public health problem in developing world like India, larva migrans remains a neglected zoonosis. Cutaneous larva migrans, Visceral larva migrans,... (Review)
Review
Despite an important public health problem in developing world like India, larva migrans remains a neglected zoonosis. Cutaneous larva migrans, Visceral larva migrans, and Ocular larva migrans are the important clinical manifestations seen in humans in India. Although many nematode parasites have the ability to cause the infection, the disease primarily occurs due to Ancylostoma caninum and Toxocara canis. Presence of the infection in dogs is an indirect indication of its incidence in humans in endemic regions. In India, sporadic cases of this neglected but important parasitic zoonosis are the main implications of lack of diagnostic methods and under-reporting of human cases. Tropical climate in addition to overcrowding, poor hygiene and sanitation problems, stray dogs, open defecation by dogs and improper faecal disposal are the important factors for persistence of this disease in the country. Sanitary and hygienic measures, improved diagnostic techniques and surveillance programme in dogs as well as humans should be adopted for its effective control. Comprehensive collaborative efforts by physicians and veterinarians are required to tackle this problem in order to attain optimal health for humans, animals and the environment. Moreover, recognition of larva migrans as an important public health problem is the most important step to combat this neglected disease in developing countries like India.
PubMed: 26688621
DOI: 10.1007/s12639-013-0402-6 -
Revista Brasileira de Parasitologia... 2023Gastrointestinal parasitism by helminths and protozoa poses risks to animal and human health owing to clinical changes and transmission of potentially zoonotic agents....
Gastrointestinal parasitism by helminths and protozoa poses risks to animal and human health owing to clinical changes and transmission of potentially zoonotic agents. Thus, the present study aimed to verify the occurrence of gastrointestinal parasites in dogs from the municipality of Cuiabá, Mato Grosso, Brazil, using coproparasitological tests. From June 2021 to April 2022, faecal samples were collected from domestic dogs at the Veterinary Hospital and Animal Protection Shelters in the Cuiabá municipality. A semi-structured questionnaire was applied to the owners and those responsible for the shelters to analyse the factors associated with gastrointestinal parasitism. A total of 353 faecal samples were collected and subjected to parasitological flotation and sedimentation techniques. Data were analysed using the chi-squared test and exploratory factorial analysis. The occurrence of gastrointestinal parasitism was 22.66% and the parasites found alone or in mixed infections were Ancylostoma spp., Trichuris vulpis, Toxocara spp., Dipylidium caninum, Cystoisospora spp., Giardia duodenalis, and coccidia. It was concluded that the occurrence of gastrointestinal parasites in dogs is frequent, and the variables associated with these infections were source origin, breed, age, coexistence with other animals, and dull fur.
Topics: Humans; Animals; Dogs; Parasites; Brazil; Dog Diseases; Prevalence; Intestinal Diseases, Parasitic; Feces
PubMed: 36651423
DOI: 10.1590/S1984-29612023004 -
The Journal of Biological Chemistry Jul 2021The prevalence of autoimmune diseases is on the rise globally. Currently, autoimmunity presents in over 100 different forms and affects around 9% of the world's...
The prevalence of autoimmune diseases is on the rise globally. Currently, autoimmunity presents in over 100 different forms and affects around 9% of the world's population. Current treatments available for autoimmune diseases are inadequate, expensive, and tend to focus on symptom management rather than cure. Clinical trials have shown that live helminthic therapy can decrease chronic inflammation associated with inflammatory bowel disease and other gastrointestinal autoimmune inflammatory conditions. As an alternative and better controlled approach to live infection, we have identified and characterized two peptides, Acan1 and Nak1, from the excretory/secretory component of parasitic hookworms for their therapeutic activity on experimental colitis. We synthesized Acan1 and Nak1 peptides from the Ancylostoma caninum and Necator americanus hookworms and assessed their structures and protective properties in human cell-based assays and in a mouse model of acute colitis. Acan1 and Nak1 displayed anticolitic properties via significantly reducing weight loss and colon atrophy, edema, ulceration, and necrosis in 2,4,6-trinitrobenzene sulfonic acid-exposed mice. These hookworm peptides prevented mucosal loss of goblet cells and preserved intestinal architecture. Acan1 upregulated genes responsible for the repair and restitution of ulcerated epithelium, whereas Nak1 downregulated genes responsible for epithelial cell migration and apoptotic cell signaling within the colon. These peptides were nontoxic and displayed key immunomodulatory functions in human peripheral blood mononuclear cells by suppressing CD4 T cell proliferation and inhibiting IL-2 and TNF production. We conclude that Acan1 and Nak1 warrant further development as therapeutics for the treatment of autoimmunity, particularly gastrointestinal inflammatory conditions.
Topics: Amino Acid Sequence; Ancylostoma; Ancylostomatoidea; Animals; Cell Proliferation; Colitis; Cytokines; Disease Models, Animal; Gene Expression Regulation; Humans; Inflammation Mediators; Intestines; Kv1.3 Potassium Channel; Leukocytes; Magnetic Resonance Spectroscopy; Male; Mice, Inbred C57BL; Necator americanus; Peptides; Principal Component Analysis; Protein Domains; Protein Folding; T-Lymphocytes; Trinitrobenzenesulfonic Acid; Xenopus laevis; Mice
PubMed: 34051231
DOI: 10.1016/j.jbc.2021.100834 -
Revista Brasileira de Parasitologia... 2021This study aimed to identify the intestinal parasites of road-killed wild felines in the North Central and North, Paraná state, southern Brazil. The animals were...
This study aimed to identify the intestinal parasites of road-killed wild felines in the North Central and North, Paraná state, southern Brazil. The animals were monitored by sampling previously established transects. The places where the felines were run over were mapped, the animals were identified, and the gastrointestinal tract was evaluated. The feces were submitted to coproparasitological techniques of spontaneous sedimentation, floating in hypersaturated NaCl solution and centrifugal floating in zinc sulfate. All the parasitic structures detected were photomicrographed. In the coproparasitological analyses were identified oocysts of Cystoisospora spp., eggs of Ancylostomatidae, and Capillaria spp.; eggs of Aelurostrongylus spp., Toxocara spp., Physaloptera spp., Taenia spp., and Spirometra spp.; Aelurostrongylus abstrusus larvae; and eggs and adults of Ancylostoma cati and Taenia spp. One of the cats was parasitized by a flea of Ctenocephalides felis felis. Based on these results, the animals analyzed in this study supplied important samples for the evaluation of parasitic diversity of North of Paraná and suggested that this region may have conditions that allow the maintenance of these parasites life cycles in the environment and among wildlife.
Topics: Animals; Animals, Wild; Biodiversity; Brazil; Cat Diseases; Cats; Feces; Intestinal Diseases, Parasitic; Parasites; Parasitic Diseases, Animal; Prevalence
PubMed: 33605387
DOI: 10.1590/S1984-296120201090 -
Pathogens (Basel, Switzerland) May 2020Both S and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, and some species of hookworms infect...
Both S and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, and some species of hookworms infect canids and therefore present both environmental and zoonotic sources of transmission to humans. Currently, there is limited information available on the prevalence of hookworms and infections in dogs living in communities across the Northern Territory in Australia. In this study, 274 dog faecal samples and 11 faecal samples of unknown origin were collected from the environment and directly from animals across 27 remote communities in Northern and Central Australia. Samples were examined using real-time polymerase chain reaction (PCR) analysis for the presence of and four hookworm species: and . The prevalence of in dogs was found to be 21.9% (60/274). was the only hookworm detected in the dog samples, with a prevalence of 31.4% (86/274). This study provides an insight into the prevalence of and hookworms in dogs and informs future intervention and prevention strategies aimed at controlling these parasites in both dogs and humans A "One Health" approach is crucial for the prevention of these diseases in Australia.
PubMed: 32455702
DOI: 10.3390/pathogens9050398 -
Revista Brasileira de Parasitologia... 2022Millions of people worldwide, and especially schoolchildren, may be infected by geohelminths due to their exposure to a contaminated environment. The aim of this study...
Millions of people worldwide, and especially schoolchildren, may be infected by geohelminths due to their exposure to a contaminated environment. The aim of this study was to evaluate soil contamination by Ancylostoma spp. and Toxocara spp. eggs in recreation areas at elementary schools in Pelotas, state of Rio Grande do Sul, Brazil. Sand samples were collected from 22 schools and were processed using the centrifugal flotation method. Helminth eggs with zoonotic potential were found in 12 out of the 22 schools (54.5%). Contamination by Ancylostoma spp. and Toxocara spp. was observed in 36.4% (8/22) and 27.3% (6/22) of the soil samples collected at these schools, respectively. These findings of eggs show that the school communities are exposed to risks of zoonotic transmission.
Topics: Ancylostoma; Animals; Brazil; Parasite Egg Count; Schools; Soil; Toxocara
PubMed: 35019029
DOI: 10.1590/S1984-29612022003 -
PLoS Neglected Tropical Diseases Feb 2021Intestinal parasitic diseases are a global health problem. Due to its equatorial climate, vast territory with isolated areas and the precariousness of its population,...
INTRODUCTION
Intestinal parasitic diseases are a global health problem. Due to its equatorial climate, vast territory with isolated areas and the precariousness of its population, intestinal parasitosis is considered to be a major issue in French Guiana but only few data are available and these mainly focus on specific population. We aimed at determining the parasitic index and at describing the characteristics of these infections in order to develop preventive strategies.
MATERIAL AND METHODS
We retrospectively analysed all the parasitological samples recorded in the register of the two main laboratories of French Guiana between 2011 and 2016. The parasitic index was the percentage of parasitised patients in comparison with the total number of subjects studied. A patient who underwent several positive parasitological examinations was considered only once in the analysis at the time of the first sampling.
RESULTS
A total of 15,220 parasitological samples of 9,555 patients were analysed and 2,916 were positive in 1,521 patients. The average infestation rate and parasitic index were 19.2% and 16.0%, respectively. The parasitic index remained stable between 2011 (18.2%) and 2016 (18.3%). The patients were mainly men (66.4%), with a median age of 33.0 years (26.3% of patients were under 18 years of age) and lived mainly in the Central Agglomeration (48.2%) and in West Guiana (37.4%). Hookworms were the most common parasite (25.2%) followed by Entamoeba coli (13.3%), Strongyloides stercoralis (10.9%) and Giardia intestinalis (10.8%). Among the infected patients, 31.0% presented mixed infections and 67.5% of them had at least one pathogenic parasite. The patients aged from 0 to 18 years presented significantly more polyparasitism (30.9%) than monoparasitism (24.3%, p<0.001). Ancylostoma sp and Strongyloides stercoralis were mainly diagnosed during the rainy season (59.5% and 64.7% respectively), in men (78.6% and 81.1% respectively) and in patients aged from 18 to 65 years (86.6% and 76.6% respectively) whereas, Giardia intestinalis infected mostly children under 5 years (59.5%) of age.
CONCLUSION
Although it may not be representative of the entire Guyanese population, the parasitic index remained high and stable from 2011 and 2016 and it justifies the need for an active prevention program as it was already done in the other French overseas departments such as Martinique and Guadeloupe.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Ancylostomatoidea; Animals; Child; Child, Preschool; French Guiana; Guadeloupe; Hospitals; Humans; Infant; Intestinal Diseases, Parasitic; Male; Martinique; Middle Aged; Parasites; Prevalence; Retrospective Studies; Strongyloides stercoralis; Young Adult
PubMed: 33544715
DOI: 10.1371/journal.pntd.0009087 -
Pathogens (Basel, Switzerland) May 2021The European wildcat () is the only wild felid living in Greece. Wildcat populations are declining due to anthropogenic and phenological unfavourable conditions, and...
The European wildcat () is the only wild felid living in Greece. Wildcat populations are declining due to anthropogenic and phenological unfavourable conditions, and parasites may have an additional negative impact. In the present study, the occurrence of endoparasites in wildcats in Greece and the potential threats posed to wildcats, domestic animals, and humans in the study areas has been investigated. In a six-year period, 23 road-killed wildcats and 62 wildcat faecal samples were collected from different areas of the country. Necropsy for the detection of endoparasites and standard parasitological examinations of faecal samples were performed. Parasites were morphologically identified and, in selected cases, molecularly analysed. All necropsied wildcats (100%) were infected by three to 10 different parasite taxa, with the most prevalent being (73.9%), (60.9%), (56.5%), (39.1%), spp. (34.8%), (34.8%), and (33.8%). Of the 62 faecal samples examined, 53 (85.5%) were positive for one or more parasite elements (larvae, eggs, or oocysts). The most frequent were (45.2%), (29%), (24.2%), and Ancylostomatidae (17.7%). This is the first survey on endoparasites affecting wildcats in Greece. Some of the parasites here found are frequent in domestic and wild felids, while others, i.e., and , were described for the first time in the European wildcat. Most of them have a significant pathogenic potential, causing severe to hazardous diseases to infected felids and some, under specific circumstances, can also threaten human health.
PubMed: 34068209
DOI: 10.3390/pathogens10050594