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PLoS Neglected Tropical Diseases Dec 2020Soil-transmitted helminth (STH) infections are endemic in Indonesia. However, prevalence data for many parts of the country are incomplete. The aim of this study was to...
Soil-transmitted helminth (STH) infections are endemic in Indonesia. However, prevalence data for many parts of the country are incomplete. The aim of this study was to determine human STH prevalence and knowledge and practices relating to STH risk behaviour, to provide a current view of the status of STH infection in rural communities in Central Java. A cross-sectional survey of 16 villages was conducted in Semarang, Central Java in 2015. Demographic and household data together with information about knowledge and practices relating to STH and hygiene were elicited through face-to-face interviews. Stool samples were collected and examined using the flotation method. Children (aged 2-12 years) also had their haemoglobin (Hb) levels, height and weight data collected, and BMI estimated. Data were analysed using univariate logistic regression analysis. A total of 6,466 individuals with a mean age of 33.5 years (range: 2-93) from 2,195 households were interviewed. The overall prevalence of STH was 33.8% with Ascaris lumbricoides (roundworm) the predominant nematode identified (prevalence = 26.0%). Hookworm and Trichuris trichiura (whipworm) were found in 7.9% and 1.8% of participants, respectively. Females were at increased odds of infection with A. lumbricoides (adjusted OR 1.14, 95% CI [1.02-1.29], p = 0.02). Adults in age groups 51-60 and over 60 years had the highest odds of being infected with hookworm (adjusted OR 3.01, 95% CI [1.84-4.91], p<0.001 and adjusted OR 3.79, 95% CI [2.30-6.26], p<0.001, respectively) compared to 6-12 year olds. Farmers also had higher odds of being infected with hookworm (adjusted OR 2.36, 95% CI [1.17-4.76], p = 0.02) compared to other occupation categories. Poverty (OR 2.14, 95% CI [1.77-2.58], p<0.001), overcrowding (OR 1.35, 95% CI [1.27-1.44], p<0.001), goat ownership (OR 1.61, 95% CI [1.10-2.41], p = 0.02) and the presence of dry floor space in the home (OR 0.73, 95% CI [0.58-0.91], p = 0.01) were all household factors significantly associated with an increased odds of infection. Infection with STH was not significantly associated with the gastrointestinal illness (p>0.05), BMI or Hb levels; however, one third of all 2-12 year olds surveyed were found to be anaemic (i.e. Hb concentrations below 110g/l or 115g/l for children under 5 and 5 years or older, respectively), with a greater proportion of school-age children at risk. Knowledge and behaviour related to hygiene and gastrointestinal diseases varied widely and were generally not associated with STH infection. The study revealed that STH infection remains endemic in Central Java despite ongoing deworming programs. Current control efforts would benefit from being re-evaluated to determine a more effective way forward.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Ancylostomatoidea; Animals; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Cross-Sectional Studies; Farmers; Feces; Female; Gastrointestinal Diseases; Hookworm Infections; Humans; Hygiene; Indonesia; Male; Middle Aged; Sanitation; Soil; Surveys and Questionnaires; Trichuriasis; Trichuris; Young Adult
PubMed: 33370267
DOI: 10.1371/journal.pntd.0008907 -
Frontiers in Veterinary Science 2022Ascariasis is the most prevalent helminthic disease affecting both humans and pigs and is caused by the roundworms and . While preventive chemotherapy continues to be...
Ascariasis is the most prevalent helminthic disease affecting both humans and pigs and is caused by the roundworms and . While preventive chemotherapy continues to be the most common control method, recent reports of anthelminthic resistance highlight the need for development of a vaccine against ascariasis. The aim of this study was to use a reverse vaccinology approach to identify potential vaccine candidates for . Three proteomes predicted from whole-genome sequences were analyzed. Candidate proteins were identified using open-access bioinformatic tools (e.g., Vacceed, VaxiJen, Bepipred 2.0) which test for different characteristics such as sub-cellular location, T-cell and B-cell molecular binding, antigenicity, allergenicity and phylogenetic relationship with other nematode proteins. From over 100,000 protein sequences analyzed, four transmembrane proteins were predicted to be non-allergen antigens and potential vaccine candidates. The four proteins are a Piezo protein, two voltage-dependent calcium channels and a protocadherin-like protein, are all expressed in either the muscle or ovaries of both species, and all contained high affinity epitopes for T-cells and B-cells. The use of a reverse vaccinology approach allowed the prediction of four new potential vaccination targets against ascariasis in humans and pigs. These targets can now be further tested in and assays to prove efficacy in both pigs and humans.
PubMed: 36387396
DOI: 10.3389/fvets.2022.1014198 -
PLoS Neglected Tropical Diseases Feb 2019
Topics: Animals; Ascaris; Ovum; Sewage; Wastewater; Water Purification
PubMed: 30789908
DOI: 10.1371/journal.pntd.0007020 -
Scientific Reports Aug 2022Preventive chemotherapy (PC) that remains the main control strategy recommended by the World Health Organization to achieve the elimination of soil-transmitted helminth...
Preventive chemotherapy (PC) that remains the main control strategy recommended by the World Health Organization to achieve the elimination of soil-transmitted helminth (STH) infections as a public health problem must be strengthened by identifying the remaining transmission hot-spots for the deployment of appropriate control measures. This study was designed to assess the prevalence and infections intensities of soil-transmitted helminths and perform micro scale mapping in order to identify transmission hot-spots for targeted control operations. Stool samples were collected from 1775 children in ten primary schools of eight sub-districts of Makenene in Cameroon. Kato Katz technique was used to process and examine stool samples to detect the eggs of soil-transmitted nematodes. The prevalence of soil-transmitted helminth species as well as the infection intensities was compared. Data visualizations in forms of maps were made using Quantum geographic information system (QGIS) software. The overall prevalence of soil-transmitted helminth infections was 4.8% with a 95% confidence interval (CI) of 3.8-5.9%: 3.0% (95% CI 2.2-3.9) for Ascaris lumbricoides, 1.4% (95% CI 0.9-2.0) for Trichuris trichiura and 0.8% (95% CI 0.5-1.4) for hookworms. The prevalence of soil-transmitted helminth species differ significantly between schools and sub-districts. The intensity of infections was light (2.4%, 1.1% and 0.8%), moderate (0.4%, 0.1% and 0.1%) and heavy (0.2%, 0.2% and 0%) for A. lumbricoides, T. trichiura and hookworm respectively. The mean intensity of infections was 7255 EPG for A. lumbricoides, 2900 EPG for T. trichiura and 298 EPG for hookworm. Between schools, significant difference was recorded in the means of infection intensities of T. Trichiura and hookworms but not for A. lumbricoides. This difference was also significant for T. Trichiura when comparison were between sex. No significant difference were recorded when the comparison were between age. Fine mapping revealed that children harbouring heavy infections were clustered in the same sub-districts; highlighting the presence of high endemicity sub-districts and hot-spots for the transmission of different soil-transmitted helminth species. This study showed a diversity in the prevalence and transmission of different soil-transmitted helminth species. It also hightlighted the need for micro scale mapping to enable the localisation of high endemicity sub-districts and transmission hot-spot sites where targeted control operations must be deployed to achieve STH elimination.
Topics: Ancylostomatoidea; Animals; Ascaris lumbricoides; Child; Feces; Helminthiasis; Helminths; Hookworm Infections; Humans; Prevalence; Soil; Trichuris
PubMed: 35978014
DOI: 10.1038/s41598-022-18285-7 -
BMC Veterinary Research Apr 2024Parasitic infestations have a substantial economic impact on pig production. This study aimed to investigate the gastrointestinal (GI) helminths in pigs and to...
A survey of gastrointestinal helminth infestation in smallholder backyard pigs and the first molecular identification of the two zoonotic helminths Ascaris suum and Trichuris suis in Myanmar.
BACKGROUND
Parasitic infestations have a substantial economic impact on pig production. This study aimed to investigate the gastrointestinal (GI) helminths in pigs and to molecularly characterise two important nematodes, Ascaris and Trichuris species.
MATERIALS AND METHODS
A total of 500 pig faecal samples were collected from small holder backyard pig farms in five townships within Nay Pyi Taw, Myanmar. Microscopic examination was conducted to estimate the prevalence of GI helminth infestation in the pigs. DNA extraction and PCR were performed on faecal samples that were morphologically positive for Ascaris and Trichuris eggs. Molecular analysis was then conducted to characterise A. suum and T. suis, the most common and zoonotic helminths.
RESULTS
According to microscopic examination, 69.2% (346/500) were positive for GI helminth eggs. The GI helminth species observed were A. suum, Strongyle, Strongyloides spp., T. suis, Metastrongylus spp., Hyostrongylus spp., Fasciolopsis spp., Paragonimus spp., and Schistosoma spp., with occurrences of 34.8%, 29.6%, 21.4%, 20.0%, 4.0%, 1.6%, 1.0%, 1.0%, and 0.4%, respectively. Mixed infections of GI helminths were noted in 31.0% of the samples. Overall, sampled pigs excreted mostly low levels (< 100 EPG) or moderate levels (> 100-500 EPG) of GI helminth eggs. The highest mean EPG for each parasite species was noted in A. suum. The presence of A. suum and T. suis was confirmed molecularly. The sequences of the internal transcribed spacer 1 (ITS1) region of A. suum showed high similarity with previously reported sequences. Likewise, the sequences of T. suis exhibited high similarity with the sequences reported from humans and pigs. Age was noted as an associated factor (P < 0.05) for GI helminth infection status.
CONCLUSIONS
In this report, A. suum and T. suis were molecularly identified for the first time in Myanmar. It is important to extend the information among the farmers to be aware of the necessity of preventing zoonotic parasites by practicing regular deworming, proper use of anthelmintics and maintaining hygienic conditions in their pig farms.
Topics: Humans; Animals; Swine; Ascaris suum; Trichuris; Myanmar; Ovum; Helminths; Feces; Swine Diseases
PubMed: 38582856
DOI: 10.1186/s12917-024-03998-w -
Frontiers in Immunology 2022Helminths produce excretory/secretory products (E/S) which can modulate the immune responses of their hosts. Dendritic cells (DC) are essential for initiating the host T...
Helminths produce excretory/secretory products (E/S) which can modulate the immune responses of their hosts. Dendritic cells (DC) are essential for initiating the host T cell response and are thus potential targets for modulation by helminth E/S. Here we study immunomodulation of porcine peripheral blood DC subsets following stimulation with E/S from , a common helminth of pigs with considerable public health and economic importance. Our data showed that the relative frequencies of DC subsets in porcine blood differ, with plasmacytoid DC (pDC) being the most prominent in healthy 6-month-old pigs. pDC are an important cytokine source, and we found that E/S suppressed production of the type 1 cytokines IL-12p40 and TNF-α by this subset following toll-like receptor (TLR) ligation. In contrast, conventional DC (cDC) are more efficient antigen presenters, and the expression of CD80/86, costimulatory molecules essential for efficient antigen presentation, were modulated differentially by E/S between cDC subsets. CD80/86 expression by type 1 cDC (cDC1) following TLR ligation was greatly suppressed by the addition of E/S, while CD80/86 expression by type 2 cDC (cDC2) was upregulated by E/S. Further, we found that IFN-γ production by natural killer (NK) cells following IL-12 and IL-18 stimulation was suppressed by E/S. Finally, in the presence of E/S, IFN-γ production by CD4+ T cells co-cultured with autologous blood-derived DC was significantly impaired. Together, these data provide a coherent picture regarding the regulation of type 1 responses by E/S. Responsiveness of pDC and cDC1 to microbial ligands is reduced in the presence of E/S, effector functions of Th1 cells are impaired, and cytokine-driven IFN-γ release by NK cells is limited.
Topics: Swine; Animals; Ascaris suum; Dendritic Cells; Interleukin-12; Cytokines; Toll-Like Receptors; Killer Cells, Natural
PubMed: 36439124
DOI: 10.3389/fimmu.2022.1012717 -
PLoS Neglected Tropical Diseases May 2023Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we... (Clinical Trial)
Clinical Trial
A general framework to support cost-efficient fecal egg count methods and study design choices for large-scale STH deworming programs-monitoring of therapeutic drug efficacy as a case study.
BACKGROUND
Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we present a framework to provide evidence-based recommendations, using a case study of therapeutic drug efficacy monitoring based on the examination of helminth eggs in stool.
METHODS
We performed an in-depth analysis of the operational costs to process one stool sample for three diagnostic methods (Kato-Katz, Mini-FLOTAC and FECPAKG2). Next, we performed simulations to determine the probability of detecting a truly reduced therapeutic efficacy for different scenarios of STH species (Ascaris lumbricoides, Trichuris trichiura and hookworms), pre-treatment infection levels, survey design (screen and select (SS); screen, select and retest (SSR) and no selection (NS)) and number of subjects enrolled (100-5,000). Finally, we integrated the outcome of the cost assessment into the simulation study to estimate the total survey costs and determined the most cost-efficient survey design.
PRINCIPAL FINDINGS
Kato-Katz allowed for both the highest sample throughput and the lowest cost per test, while FECPAKG2 required both the most laboratory time and was the most expensive. Counting of eggs accounted for 23% (FECPAKG2) or ≥80% (Kato-Katz and Mini-FLOTAC) of the total time-to-result. NS survey designs in combination with Kato-Katz were the most cost-efficient to assess therapeutic drug efficacy in all scenarios of STH species and endemicity.
CONCLUSIONS/SIGNIFICANCE
We confirm that Kato-Katz is the fecal egg counting method of choice for monitoring therapeutic drug efficacy, but that the survey design currently recommended by WHO (SS) should be updated. Our generic framework, which captures laboratory time and material costs, can be used to further support cost-efficient choices for other important surveys informing STH control programs. In addition, it can be used to explore the value of alternative diagnostic techniques, like automated egg counting, which may further reduce operational costs.
TRIAL REGISTRATION
ClinicalTrials.gov NCT03465488.
Topics: Animals; Humans; Ascaris lumbricoides; Feces; Helminthiasis; Helminths; Sensitivity and Specificity; Soil; Trichuris
PubMed: 37196017
DOI: 10.1371/journal.pntd.0011071 -
Journal of Immunology (Baltimore, Md. :... Jul 2018Epigenetic mechanisms, such as DNA methylation, determine immune cell phenotype. To understand the epigenetic alterations induced by helminth coinfections, we evaluated...
Epigenetic mechanisms, such as DNA methylation, determine immune cell phenotype. To understand the epigenetic alterations induced by helminth coinfections, we evaluated the longitudinal effect of ascariasis and schistosomiasis infection on CD4 T cell DNA methylation and the downstream tuberculosis (TB)-specific and bacillus Calmette-Guérin-induced immune phenotype. All experiments were performed on human primary immune cells from a longitudinal cohort of recently TB-exposed children. Compared with age-matched uninfected controls, children with active and infection had 751 differentially DNA-methylated genes, with 72% hypermethylated. Gene ontology pathway analysis identified inhibition of IFN-γ signaling, cellular proliferation, and the Th1 pathway. Targeted real-time quantitative PCR after methyl-specific endonuclease digestion confirmed DNA hypermethylation of the transcription factors , , , , , , and and cytokines or cytokine receptors , , (TNF receptor), and ( < 0.001; Sidak-Bonferroni). Functional blockage of the IFN-γ signaling pathway was confirmed, with helminth-infected individuals having decreased upregulation of IFN-γ-inducible genes (Mann-Whitney < 0.05). Hypomethylation of the IL-4 pathway and DNA hypermethylation of the Th1 pathway was confirmed by Ag-specific multidimensional flow cytometry demonstrating decreased TB-specific IFN-γ and TNF and increased IL-4 production by CD4+ T cells (Wilcoxon signed-rank < 0.05). In -infected individuals, these DNA methylation and immune phenotypic changes persisted at least 6 mo after successful deworming. This work demonstrates that helminth infection induces DNA methylation and immune perturbations that inhibit TB-specific immune control and that the duration of these changes are helminth specific.
Topics: Animals; Ascariasis; Ascaris lumbricoides; BCG Vaccine; Cell Proliferation; Cells, Cultured; DNA Methylation; Humans; Interferon-gamma; Interleukin-4; Receptors, Cytokine; Schistosoma haematobium; Schistosomiasis; Th1 Cells; Transcription Factors; Tuberculosis
PubMed: 29752313
DOI: 10.4049/jimmunol.1800101 -
International Journal For Parasitology.... Dec 2017Control of human soil-transmitted helminths (STHs) relies on preventive chemotherapy of schoolchildren applying the benzimidazoles (BZ) albendazole or mebendazole....
Control of human soil-transmitted helminths (STHs) relies on preventive chemotherapy of schoolchildren applying the benzimidazoles (BZ) albendazole or mebendazole. Anthelmintic resistance (AR) is a common problem in nematodes of veterinary importance but for human STHs, information on drug efficacy is limited and routine monitoring is rarely implemented. Herein, the efficacy of single dose albendazole (400 mg) was evaluated in 12 schools in the Huye district of Rwanda where Ascaris is the predominant STH. Ascaris eggs were detected by wet mount microscopy and the Mini-FLOTAC method to assess cure rate (CR) and faecal egg count reduction (FECR). Blood and faecal samples were analysed for co-infections with Plasmodium sp. and Giardia duodenalis, respectively. Ascaris positive samples collected before and after treatment were analysed for putatively BZ-resistance associated β-tubulin gene single nucleotide polymorphisms. The overall CR was 69.9% by Mini-FLOTAC and 88.6% by wet mount microscopy. The FECR was 75.4% and the 95% calculated confidence intervals were 50.4-87.8% using sample variance, 55.4-88.8% by bootstrapping, and 75.0-75.7% applying a Markov Chain Monte Carlo Bayesian approach. FECR varied widely between 0 and 96.8% for individual schools. No putative BZ-resistance associated polymorphisms were found in the four Ascaris β-tubulin isotype genes examined. Since FECRs <95% indicate reduced efficacy, these findings raise the suspicion of BZ resistance. In the absence of respective molecular evidence, heritable AR in the local Ascaris populations cannot be formally proven. However, since FECRs <95% indicate reduced efficacy, BZ resistance may be suspected which would be alarming and calls for further analyses and routine monitoring in preventive chemotherapy programs.
Topics: Albendazole; Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Bayes Theorem; Benzimidazoles; Child; Coinfection; Drug Resistance; Feces; Female; Humans; Male; Parasite Egg Count; Rwanda; Schools; Soil; Students; Tubulin
PubMed: 28697451
DOI: 10.1016/j.ijpddr.2017.06.001 -
Przeglad Epidemiologiczny 2018Co-infections of HIV and other pathogens constitute an important clinical and epidemiological problem. Many studies have played attention to opportunistic co-infections... (Review)
Review
Selected aspects of helminth infections Schistosoma sp., Ascaris lumbricoides, Strongyloides stercoralis in individuals diagnosed with human immunodeficiency virus (HIV) infection.
Co-infections of HIV and other pathogens constitute an important clinical and epidemiological problem. Many studies have played attention to opportunistic co-infections due to the fact that they are used as an indicator for development of AIDS and are present on the all continents. However, in HIV-infected patients helminth infections, which are not aetiologic agents of opportunistic infections, are becoming more and more important. Prevalence of helminth infection depends on parasite species, environmental and socio-economic factors, therefore the results of published research mainly refer to populations of patients in developing countries and endemic regions. In many cases, pathogenetic mechanisms of these co-infections are not fully recognized, and the obtained results are ambiguous. Thus we performed literature review concerning the course and implications of co-infections with three selected helminth species, of different tissue/organ tropism (Ascaris lumbricoides, Strongyloides stercoralis, Schistosoma sp.), in patients with HIV infection.
Topics: Animals; Ascariasis; Ascaris lumbricoides; Coinfection; HIV Infections; Helminthiasis; Humans; Strongyloides stercoralis; Strongyloidiasis
PubMed: 30394059
DOI: 10.32394/pe.72.3.11