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Global prevalence of Ascaris infection in humans (2010-2021): a systematic review and meta-analysis.Infectious Diseases of Poverty Nov 2022Ascariasis is one of the most important neglected tropical diseases of humans worldwide. The epidemiology of Ascaris infection appears to have changed with improvements... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Ascariasis is one of the most important neglected tropical diseases of humans worldwide. The epidemiology of Ascaris infection appears to have changed with improvements in sanitation and mass drug administration, but there is no recent information on prevalence worldwide. Here, we performed a systematic review and meta-analysis to assess the global prevalence of human Ascaris infection from 2010 to 2021.
METHODS
We searched MEDLINE/PubMed, and Scopus databases for studies measuring prevalence of Ascaris infection, published between 1 January 2010 and 1 January 2022. We included studies of the general human population in endemic regions, which used accepted coprodiagnostic methods, and excluded studies of people with occupations with an increased risk or probability of ascariasis and/or specific diseases other than ascariasis. We applied random-effects models to obtain pooled prevalence estimates for six sustainable development goal regions of the world. We extrapolated the prevalence estimates to the global population in 2020, to estimate the number of individuals with Ascaris infection. We conducted multiple subgroup and meta-regression analyses to explore possible sources of heterogeneity, and to assess relationships between prevalence estimates and demographic, socio-economic, geo-climatic factors.
RESULTS
Of 11,245 studies screened, we analysed 758 prevalence estimates for a total number of 4,923,876 participants in 616 studies from 81 countries. The global prevalence estimated was 11.01% (95% confidence interval: 10.27-11.78%), with regional prevalences ranging from 28.77% (7.07-57.66%) in Melanesia (Oceania) to 1.39% (1.07-1.74%) in Eastern Asia. We estimated that ~ 732 (682-782) million people harboured Ascaris worldwide in 2021. The infected people in Latin America and the Caribbean region had a higher prevalence of high intensity infection (8.4%, 3.9-14.1%). Prevalence estimates were higher in children, and people in rural communities or in countries or regions with lower income and human development indices. There was a trend for a higher prevalence in regions with increasing mean annual relative humidity, precipitation and environmental temperature.
CONCLUSIONS
Our findings indicate that, despite a renewed commitment by some communities or authorities to control ascariasis, a substantial portion of the world's human population (> 0.7 billion) is infected with Ascaris. Despite the clinical and socioeconomic importance of ascariasis, many past routine surveys did not assess the intensity of Ascaris infection in people. We propose that the present findings might stimulate the development of customised strategies for the improved control and prevention of Ascaris infection worldwide.
Topics: Humans; Child; Ascariasis; Prevalence; Rural Population; Latin America
PubMed: 36401308
DOI: 10.1186/s40249-022-01038-z -
Allergy, Asthma, and Clinical... 2020Substantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent. Unlike to...
BACKGROUND
Substantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent. Unlike to asthma, the association between helminthes infection and allergic rhinitis (AR) has been poorly studied. Therefore, we sought to evaluate the association between exposure to and infections and AR.
METHODS
We did an age- and gender-matched case-control study of 81 children with physician-confirmed AR and 101 control subjects in a referral hospital for pediatric diseases in northern Iran. Exposure to and infections was evaluated by anti-- and anti-- IgG antibodies using a commercial enzyme-linked immunosorbent assay. Associations were determined using multivariate logistic regression.
RESULTS
seropositivity was higher in children with rhinitis than in controls (12.34 vs. 3.96%). seropositivity was positively associated with AR in univariate analysis (OR, 3.42; 95% CI 1.03-11.3; P value = 0.035), but this association was not significant after adjustment for potential confounders (OR, 1.85; 95% CI 0.42-8.18). Also seropositivity was higher in children with AR than in healthy subjects (3.7% vs. 0.99), indicating non-significant association with AR in both univariate (OR, 3.84; 95% CI 0.39-37.7) and multivariate analyses (OR, 0.8; 95% CI 0.04-15.44).
CONCLUSION
Our results revealed that AR is not associated with seropositivity to and infections in general; however, a higher seropositivity rate was found for both parasites in children with AR. More studies with longitudinal design and larger sample size are needed to elucidate this association.
PubMed: 32922455
DOI: 10.1186/s13223-020-00468-4 -
Frontiers in Cellular and Infection... 2021Soil-transmitted helminths (STH) affect hundreds of millions worldwide and are some of the most important neglected tropical diseases in terms of morbidity. Due to the... (Review)
Review
Soil-transmitted helminths (STH) affect hundreds of millions worldwide and are some of the most important neglected tropical diseases in terms of morbidity. Due to the difficulty in studying STH human infections, rodent models have become increasingly used, mainly because of their similarities in life cycle. and have been proven appropriate and low maintenance models for the study of ascariasis and trichuriasis. In the case of hookworms, despite most of the murine models do not fully reproduce the life cycle of , their proteomic similarity makes them highly suitable for the development of novel vaccine candidates and for the study of hookworm biological features. Furthermore, these models have been helpful in elucidating some basic aspects of our immune system, and are currently being used by numerous researchers to develop novel molecules with immunomodulatory proteins. Herein we review the similarities in the proteomic composition between , and and their respective human counterpart with a focus on the vaccine candidates and immunomodulatory proteins being currently studied.
Topics: Animals; Ascaris lumbricoides; Helminths; Mice; Prevalence; Proteomics; Rodentia; Soil; Trichuriasis
PubMed: 33968800
DOI: 10.3389/fcimb.2021.639573 -
Nature Communications Feb 2022Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We...
Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We analyzed small RNA pathways in the divergent parasitic nematode Ascaris. Ascaris has ten Argonautes with five worm-specific Argonautes (WAGOs) that associate with secondary 5'-triphosphate 22-24G-RNAs. These small RNAs target repetitive sequences or mature mRNAs and are similar to the C. elegans mutator, nuclear, and CSR-1 small RNA pathways. Even in the absence of a piRNA pathway, Ascaris CSR-1 may still function to "license" as well as fine-tune or repress gene expression. Ascaris ALG-4 and its associated 26G-RNAs target and likely repress specific mRNAs during testis meiosis. Ascaris WAGO small RNAs demonstrate target plasticity changing their targets between repeats and mRNAs during development. We provide a unique and comprehensive view of mRNA and small RNA expression throughout spermatogenesis. Overall, our study illustrates the conservation, divergence, dynamics, and flexibility of small RNA pathways in nematodes.
Topics: Animals; Argonaute Proteins; Ascaris; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Gene Expression Regulation, Developmental; Gene Silencing; Germ Cells; Phylogeny; RNA, Messenger; RNA, Small Interfering; Spermatogenesis
PubMed: 35149688
DOI: 10.1038/s41467-022-28482-7 -
Scientific Reports Nov 2022The most frequent intestinal helminth infections in humans are attributed to Ascaris lumbricoides, and there are concerns over the anthelminthic resistance of this...
The most frequent intestinal helminth infections in humans are attributed to Ascaris lumbricoides, and there are concerns over the anthelminthic resistance of this species. The gut microbiota has essential roles in host physiology. Therefore, discovering host-parasite-microbiota interactions could help develop alternative helminthiasis treatments. Additionally, these interactions are modulated by functional metabolites that can reveal the mechanisms of infection and disease progression. Thus, we aimed to investigate bacteriomes in the gut of helminths and fecal samples of patients via next-generation sequencing. Our results showed that infection intensity was associated with the bacterial composition of helminth guts but not with the intestinal bacteriome of human hosts. Moreover, the metabolomes of A. lumbricoides in the heavy and light ascariasis cases were characterized using ultra-high performance liquid chromatography/time-of-flight mass spectrometry. Increased levels of essential biomolecules, such as amino acids, lipids, and nucleotide precursors, were found in the guts of helminths isolated from heavily infected patients, implying that these metabolites are related to egg production and ascariasis pathogenicity. These findings are the first step towards a more complete understanding of the mechanisms by which the bacteriome of helminth guts affect their colonization and may reveal novel and more effective approaches to parasitic disease therapy.
Topics: Humans; Animals; Ascaris lumbricoides; Ascariasis; Gastrointestinal Microbiome; Helminthiasis; Helminths; Feces; Metabolome
PubMed: 36376367
DOI: 10.1038/s41598-022-23608-9 -
Computational and Structural... 2023Genomic variations may cause deleterious effects on protein functionality and perturb biological processes. Elucidating the effects of variations is critical for...
BACKGROUND
Genomic variations may cause deleterious effects on protein functionality and perturb biological processes. Elucidating the effects of variations is critical for developing novel treatment strategies for diseases of genetic origin. Computational approaches have been aiding the work in this field by modeling and analyzing the mutational landscape. However, new approaches are required, especially for accurate representation and data-centric analysis of sequence variations.
METHOD
In this study, we propose ASCARIS (Annotation and StruCture-bAsed RepresentatIon of Single amino acid variations), a method for the featurization (i.e., quantitative representation) of single amino acid variations (SAVs), which could be used for a variety of purposes, such as predicting their functional effects or building multi-omics-based integrative models. ASCARIS utilizes the direct and spatial correspondence between the location of the SAV on the sequence/structure and 30 different types of positional feature annotations (e.g., active/lipidation/glycosylation sites; calcium/metal/DNA binding, inter/transmembrane regions, etc.), along with structural features and physicochemical properties. The main novelty of this method lies in constructing reusable numerical representations of SAVs via functional annotations.
RESULTS
We statistically analyzed the relationship between these features and the consequences of variations and found that each carries information in this regard. To investigate potential applications of ASCARIS, we trained variant effect prediction models that utilize our SAV representations as input. We carried out an ablation study and a comparison against the state-of-the-art methods and observed that ASCARIS has a competing and complementary performance against widely-used predictors. ASCARIS can be used alone or in combination with other approaches to represent SAVs from a functional perspective. ASCARIS is available as a programmatic tool at https://github.com/HUBioDataLab/ASCARIS and as a web-service at https://huggingface.co/spaces/HUBioDataLab/ASCARIS.
PubMed: 37822561
DOI: 10.1016/j.csbj.2023.09.017 -
Parasitology Apr 2021Human ascariasis is the most common and prevalent neglected tropical disease and is estimated that ~819 million people are infected around the globe, accounting for...
Human ascariasis is the most common and prevalent neglected tropical disease and is estimated that ~819 million people are infected around the globe, accounting for 0.861 million years of disability-adjusted life years in 2017. Even with the existence of highly effective drugs, the constant presence of infective parasite eggs in the environment contribute to a high reinfection rate after treatment. Due to its high prevalence and broad geographic distribution Ascaris infection is associated with a variety of co-morbidities and co-infections. Here, we provide data from both experimental models and humans studies that illustrate how complex is the interaction of Ascaris with the host immune system, especially, in the context of reinfections, co-infections and associated co-morbidities.
PubMed: 33843506
DOI: 10.1017/S0031182021000627 -
Parasites, Hosts and Diseases May 2023In the l950s, under the legacy of traditional agriculture, Ascaris lumbricoides, spread epidemically in the war-bitten society of Korea. Consensus on the parasite... (Review)
Review
In the l950s, under the legacy of traditional agriculture, Ascaris lumbricoides, spread epidemically in the war-bitten society of Korea. Consensus on the parasite control was drafted in the Parasite Disease Prevention Act, which passed a parliamentary agreement in 1966, and established safe disposal of feces and mass chemotherapy as control strategies. Biannual stool examinations and treating infected schoolchildren were basic scheme of the control activity through which revenue could be secured for organized business. In the 27 years following 1969, a maximum of 16 million stool examinations had been done every year. Cellophane thick smear enabled the task. The infection declined remarkably in the 1970s when industrialization and green revolution proceeded. A population study of A. lumbricoides in the late 1970s helped us better understand its epidemiology. The data also settled down the understandable protest of teachers against the repeated stool examinations. In the 9 years following 1987, the target population was gradually reduced when the egg positive rate was below 0.1%. An article in the Korean Law, stipulating obligatory stool examinations, was made optional. Although the long-term Korean effort of Ascaris control was a success, the effect of mass chemotherapy was not as succinct in terms of lowering reinfection. In the period of control, Korean agricultural technology changed, and the economy grew and supplied sanitary facilities by which the vicious cycle was disconnected. Reduction of morbidity was a benefit of mass chemotherapy, which is the only control method feasible in economically difficult countries. The most important hurdle of parasite control in the 1960s was poverty of general population and limited financial resources in Korea but the society formed a consensus on the priority of intestinal helminthiasis control during the ordeal period. The national consensus in the 1960s was the critical milestone for Ascaris control in Korea. Under the social agreement, application of timely technical and research advancements in parasitology achieved the success of ascariasis elimination. The successful experience of ascariasis elimination in Korea can be a benchmark for countries where neglected tropical diseases are endemically recycled.
Topics: Animals; Humans; Child; Ascariasis; Helminthiasis; Intestinal Diseases, Parasitic; Ascaris; Republic of Korea
PubMed: 37258258
DOI: 10.3347/PHD.22152 -
The Cochrane Database of Systematic... Apr 2020Ascaris lumbricoides is a common infection, and mainly affects children living in low-income areas. Water and sanitation improvement, health education, and drug... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Ascaris lumbricoides is a common infection, and mainly affects children living in low-income areas. Water and sanitation improvement, health education, and drug treatment may help break the cycle of transmission, and effective drugs will reduce morbidity.
OBJECTIVES
To compare the efficacy and safety of anthelmintic drugs (albendazole, mebendazole, ivermectin) for treating people with Ascaris infection.
SEARCH METHODS
We searched the Cochrane Infectious Disease Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, three other databases, and reference lists of included studies, without language restrictions, up to 4 July 2019.
SELECTION CRITERIA
Randomized controlled trials (RCT) that compared albendazole, mebendazole, and ivermectin in children and adults with confirmed Ascaris infection.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed studies for inclusion, assessed risk of bias, and extracted data from the included trials. A third review author checked the quality of data extraction. We used the Cochrane 'Risk of bias' assessment tool to determine the risk of bias in included trials. We used risk ratios (RRs) with 95% confidence intervals (CIs) to compare dichotomous outcomes in treatment and control groups. We used the fixed-effect model for studies with low heterogeneity and the random-effects model for studies with moderate to high heterogeneity. We assessed the certainty of the evidence using the GRADE approach. We used the control rate average to provide illustrative cure rates in the comparison groups.
MAIN RESULTS
We included 30 parallel-group RCTs, which enrolled 6442 participants from 17 countries across Africa, Asia, Central America and the Caribbean, and South America. Participants were from 28 days to 82 years of age, recruited from school, communities, and health facilities. Twenty studies were funded or co-funded by manufacturers, while 10 studies were independent of manufacturer funding. Twenty-two trials had a high risk of bias for one or two domains (blinding, incomplete outcome data, selective reporting). Single dose of albendazole (four trials), mebendazole (three trials) or ivermectin (one trial) was compared to placebo. Parasitological cure at 14 to 60 days was high in all the studies (illustrative cure of 93.0% in the anthelmintic group and 16.1% in the placebo group; RR 6.29, 95% CI 3.91 to 10.12; 8 trials, 1578 participants; moderate-certainty evidence). Single dose of albendazole is as effective as multiple doses of albendazole (illustrative cure of 93.2% with single dose, 94.3% with multiple doses; RR 0.98, 95% CI 0.92 to 1.05; 3 trials, 307 participants; high-certainty evidence); or as single dose of mebendazole (illustrative cure of 98.0% with albendazole, 96.9% with mebendazole; RR 1.01, 95% CI 1.00 to 1.02; 6 trials, 2131 participants; high-certainty evidence). Studies did not detect a difference between a single dose of albendazole and a single dose of ivermectin (cure rates of 87.8% with albendazole, 90.2% with ivermectin; RR 0.99, 95% CI 0.91 to 1.08; 3 trials, 519 participants; moderate-certainty evidence). Across all the studies, failure after single dose of albendazole ranged from 0.0% to 30.3%, mebendazole from 0.0% to 22.2%, and ivermectin from 0.0% to 21.6%. The egg reduction rate (ERR) measured up to 60 days after the treatment was high in all treated groups, regardless of the anthelmintic used (range 96% to 100%). It was not possible to evaluate parasitological cure by classes of infection intensity. No included trials reported complication or serious adverse events. Other adverse events were apparently similar among the compared anthelmintic groups (moderate- to low-certainty evidence). The most commonly reported other adverse events were nausea, vomiting, abdominal pain, diarrhoea, headache, and fever.
AUTHORS' CONCLUSIONS
Single-dose of albendazole, mebendazole, and ivermectin all appeared effective against Ascaris lumbricoides infection, yielding high parasitological cure and large reductions in eggs excreted, with no differences detected between them. The drugs appear to be safe to treat children and adults with confirmed Ascaris infection. There is little to choose between drugs and regimens in terms of cure or adverse events.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Albendazole; Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Humans; Infant; Ivermectin; Mebendazole; Middle Aged; Parasite Egg Count; Placebos; Randomized Controlled Trials as Topic; Young Adult
PubMed: 32289194
DOI: 10.1002/14651858.CD010599.pub2 -
The American Journal of Tropical... Aug 2020We reported 865 cases of soil-transmitted nematodiasis occurring in Japan during 2000-2017. The predominant nematode was ( = 279, 32.3% of all cases), and other species...
We reported 865 cases of soil-transmitted nematodiasis occurring in Japan during 2000-2017. The predominant nematode was ( = 279, 32.3% of all cases), and other species included (30.7%), (23.1%), and spp. (13.9%). was detected primarily in patients in Okinawa and Kagoshima prefectures, which are in the south of Japan and are endemic areas for this parasitic infection, and also in about half of the prefectures of all Japan. At least 15.5 cases of strongyloidiasis occurred on average each year. The period incidence rate of strongyloidiasis cases relative to the total population of Japan was 0.012 cases per 10 person-years. The male-to-female ratio was 2.1. The average age was 75.1 ± 16.9 years, and 96.1% of patients were older than 50 years. Several reasons may explain why this previously non-endemic outside of Okinawa region, serious nematode disease is now found in much of Japan, including the increased number of transmigration and sightseeing trips in Japan, use of immunosuppressive drugs, and lack of awareness of the risks. Thus, information of strongyloidiasis and its risks must be disseminated to travelers, residents, and physicians to prevent this life-threatening parasite infection.
Topics: Adult; Aged; Aged, 80 and over; Ancylostomiasis; Animals; Ascariasis; Ascaris lumbricoides; Female; Humans; Japan; Male; Middle Aged; Strongyloides stercoralis; Strongyloidiasis; Trichuriasis; Trichuris; Young Adult
PubMed: 32588800
DOI: 10.4269/ajtmh.19-0969