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1.
Parasit Vectors ; 15(1): 410, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333779

RESUMO

BACKGROUND: The Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing infection with soil-transmitted helminths (STH) and schistosome parasites in combination with deworming in Wolayita zone, Ethiopia. METHODS: A population-based, cross-sectional census and parasitological mapping activity was conducted between 2018 and 2019. Individuals in the census were identified using either a registered study ID card or biometric fingerprint to enable linkage of their household WaSH data with baseline STH and schistosome prevalence for risk analysis. RESULTS: Prevalence of STH was 15.5% for any STH species, 9.47% for Ascaris lumbricoides, 1.78% for Trichuris trichiura, and 7.24% for hookworm. Intestinal schistosomiasis (Schistosoma mansoni) infection prevalence was 0.85% by Kato Katz, 21.6% by POC-CCA trace positive (Tr +), and 13.3% trace negative (Tr-). Microhaematuria was 2.77%, with 0.13% of people examined with S. haematobium eggs detected by urine filtration. At the household level, increased (> 30 min) time taken to collect drinking water, sharing a latrine, and lack of handwashing facilities were all associated with a greater risk of A. lumbricoides, hookworm, and S. mansoni infection. Not disposing of infant stool at the household and clothes washing/recreational freshwater contact were significantly associated with higher risk of schistosomiasis infection. Aggregating WaSH data at the community level showed odds of A. lumbricoides, hookworm, and T. trichiura infection were significantly lower as both community sanitation coverage and access to improved drinking water improved. CONCLUSIONS: The principal finding of this study is that lack of access to WaSH, such as improved drinking water and shared toilet and hand-washing facilities, were linked to an increased risk of infection with STH and schistosome parasites. These associations are difficult to establish at an individual household level because of wide variability in access between houses but are detectable when coverage is aggregated at the community level. Maintenance of WaSH facilities as well as increased access within the whole community is important in influencing the community-wide prevalence of infection with STH and schistosome parasites.


Assuntos
Água Potável , Helmintíase , Helmintos , Infecções por Uncinaria , Schistosomatidae , Lactente , Animais , Humanos , Saneamento , Solo/parasitologia , Prevalência , Estudos Transversais , Etiópia/epidemiologia , Higiene , Infecções por Uncinaria/epidemiologia , Ancylostomatoidea , Schistosoma mansoni , Fezes/parasitologia , Helmintíase/epidemiologia
2.
Microbiol Spectr ; 10(5): e0240222, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36190423

RESUMO

Dictyostelid cellular slime molds (dictyostelids) are protists that are common inhabitants of most soils, where they feed upon bacteria. Changbai Mountain is the highest mountain in northeast China. Soil samples collected on Changbai Mountain yielded 11 isolates representing six species of dictyostelid samples. Two of these species (Dictyostelium robusticaule and Heterostelium recretum) were found to be new to science, based on morphology, SSU rDNA sequences, and an ATPase subunit 1 gene (atp1) phylogeny. The present study also demonstrated that the increased accuracy and lower costs associated with the use of atp1 sequences make them a complement of SSU rDNA sequences for identifying dictyostelids. Changbai Mountain is characterized by a higher diversity of dictyostelids than indicated by the few previous reports. Moreover, the data for Changbai Mountain, compared with comparable data for Taiwan, suggest that differences in diversity at the family level are possibly related to latitude. Mixed broadleaf-conifer forests produced more isolates and species than broadleaf forests at the same elevation and also had the highest species richness, which indicates an effect of vegetation on dictyostelids. However, the pattern of slightly decreasing diversity with increasing elevation in dictyostelids was also apparent. IMPORTANCE Dictyostelium robusticaule and Heterostelium recretum are two new species of dictyostelids reported in this study. The potential use of atp1 sequences is a complement of SSU rDNA sequences for the identifying dictyostelids. A pattern of slightly decreasing diversity with increasing elevation in dictyostelids was observed, with the conditions that exist at lower elevations apparently more suitable for dictyostelids, whereas differences of diversity observed at the family level are possibly related to latitude.


Assuntos
Dictyosteliida , Solo , Adenosina Trifosfatases , China , Dictyosteliida/genética , Dictyostelium/genética , DNA Ribossômico/genética , Florestas , Solo/parasitologia
3.
PLoS One ; 17(10): e0276137, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36251667

RESUMO

Soil-transmitted helminths (STH) is a term used to refer to infections caused by intestinal worms mainly due to A. lumbricoides, T. trichiura, and hookworm species which are transmitted through contaminated soil. This study was conducted to assess the prevalence and intensity of STHs infection among individual members living within the selected household heads (HHs) certified either as a model HHs or non-model HHs based on the implementation level of a training program known as the Health Extension Program (HEP). A community-based comparative cross-sectional study was conducted from April to June 2018 at Seka Chekorsa Woreda, Jimma zone. Model and non-model HHs were selected systematically from each of the randomly selected district villages employing a multistage sampling technique. Sociodemographic and risk factors data associated with STHs infections were collected using a pre-tested structured questionnaire. Parasitological stool sample microscopic examination was done using saline wet mount and Kato Katz thick smear technique. Data analysis was performed using SPSS software version 20 for descriptive statistics, comparison, and logistic regression at a p-value < 0.05 for statistical significance. Overall, 612 individuals were recruited in the study from 120 randomly selected HHs. The prevalence of STHs infections was found to be 32.4%. A total of 45 (14.7%) model and 153 (50.0%) non-model individual participants were positive for at least one species of STHs showing a significant difference between individuals in model and non-model HHs (AOR: 6.543, 95% CI; 4.36-9.82, P<0.001). The dominant STHs were T. trichiura (21.6%) followed by A. lumbricoides (6.4%) and hookworms (2.3%). The intensity of T. trichiura and A. lumbricoides infection have shown a significant difference (p<0.05) while hookworm species infection was not significantly different (p>0.05) for the individuals in the HHs groups. On the other hand, the households training status, age of participants, and latrine use pattern were found significant predictors of STHs infection prevalence in the multivariate analysis (P<0.05). Therefore, the prevalence and intensity of STHs infection was higher among individuals living in a non-model HHs than model HHs.


Assuntos
Helmintíase , Helmintos , Infecções por Uncinaria , Ancylostomatoidea , Animais , Estudos Transversais , Etiópia/epidemiologia , Características da Família , Fezes/parasitologia , Helmintíase/epidemiologia , Helmintíase/parasitologia , Prevalência , Solo/parasitologia
4.
Trop Biomed ; 39(3): 402-411, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214437

RESUMO

Demarginalization through initiation of resettlement program since 1978 is an inevitable progress faced by the indigenous Orang Asli (OA) population in Peninsular Malaysia. As Malaysian huntergatherers, the Negrito has been exposed to various environmental-cultural variations. These changes may influence the pattern of soil-transmitted helminth (STH) infections, the common malady amongst OA. This study evaluated the deworming effects of single-dosage albendazole (400 mg) and STH-reinfection rate between Negritos who are still living in the inland jungle versus those living in resettlements at town peripheries (RPS). Stool samples from the consented participants were first examined using the direct faecal smear, formalin-ether sedimentation and Kato Katz techniques. Subsequently, stool collections were carried out in three time points following treatment (i.e., 21 days, 3 months and 6 months). In brief, a total number of 54 Negritos (inland: 24; RPS: 30) with a complete set of stool collection was included in this longitudinal study. This study revealed 72.2% cure rate against T. trichiura in the inland but only 15.0% in the RPS. Although the efficacy of albendazole against T. trichiura was ultimately low in the RPS, 62.6% egg reduction rate (ERR) (arithmetic mean) was noted (p = 0.001). For A. lumbricoides and hookworm, high cure rates were found in both communities (85.7-100.0%). Reinfection for T. trichiura was seen in less than 1 month with higher rate in the RPS (90.0%) as opposed to the inland (44.4%) at 21 days following treatment. This study found that the inland OA had better tolerability to single-dosage albendazole and experienced slower STH reinfection rates versus the RPS. Hence, the selection of albendazole dosage should be targeted and the use of single- dosage albendazole (biannually) would be more suitable for the inland OA. Conversely, we propose the use of 3-days albendazole regimens in the resettled RPS population.


Assuntos
Anti-Helmínticos , Helmintíase , Helmintos , Albendazol/uso terapêutico , Animais , Éteres/uso terapêutico , Fezes/parasitologia , Formaldeído/uso terapêutico , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Humanos , Estudos Longitudinais , Reinfecção , Solo/parasitologia
5.
PLoS Negl Trop Dis ; 16(10): e0010895, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36279298

RESUMO

Soil-transmitted helminths (STH) infect 1.5 billion people and countless animals worldwide. In Australian Indigenous communities, STH infections have largely remained endemic despite control efforts, suggesting reservoirs of infection may exist. Dogs fulfil various important cultural, social and occupational roles in Australian Indigenous communities and are populous in these settings. Dogs may also harbour zoonotic STHs capable of producing morbidity and mortality in dogs and humans. This review provides an overview of human and zoonotic STH infections, identifies the Australian Indigenous locations affected and the parasite species and hosts involved. The meta-analysis provides estimates of individual study and pooled true prevalence of STH infections in Australian Indigenous communities and identifies knowledge gaps for further research on zoonotic or anthroponotic potential. A systematic literature search identified 45 eligible studies documenting the presence of Strongyloides stercoralis, Trichuris trichiura, Ancylostoma caninum, Ancylostoma duodenale, Ancylostoma ceylanicum, undifferentiated hookworm, and Ascaris lumbricoides. Of these studies, 26 were also eligible for inclusion in meta-analysis to establish true prevalence in the light of imperfect diagnostic test sensitivity and specificity by Rogan-Gladen and Bayesian methods. These studies revealed pooled true prevalence estimates of 18.9% (95% CI 15.8-22.1) for human and canine S. stercoralis infections and 77.3% (95% CI 63.7-91.0) for canine A. caninum infections indicating continued endemicity, but considerably more heterogenous pooled estimates for canine A. ceylanicum infections, and A. duodenale, undifferentiated hookworm and T. trichiura in humans. This review suggests that the prevalence of STHs in Australian Indigenous communities has likely been underestimated, principally based on imperfect diagnostic tests. Potential misclassification of hookworm species in humans and dogs due to outdated methodology, also obscures this picture. High-quality contemporary studies are required to establish current true prevalence of parasite species in all relevant hosts to guide future policy development and control decisions under a culturally sound One Health framework.


Assuntos
Helmintíase , Helmintos , Infecções por Uncinaria , Humanos , Cães , Animais , Solo/parasitologia , Teorema de Bayes , Austrália/epidemiologia , Ascaris lumbricoides , Trichuris , Helmintíase/epidemiologia , Infecções por Uncinaria/epidemiologia , Infecções por Uncinaria/veterinária , Ancylostomatoidea , Ancylostoma , Zoonoses/epidemiologia , Prevalência , Fezes/parasitologia
6.
J Water Health ; 20(10): 1604-1610, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36308502

RESUMO

Acanthamoeba, a free-living and opportunistic protozoan parasite, is a causative agent of severe human infections of the cornea and brain. The present study evaluated the distribution and genotyping of Acanthamoeba spp. in water and soil of recreational places in various areas in Guilan province in northern Iran. Eighty water and 20 soil samples were collected from the study area. Water samples were vacuum filtered through a 0.45 µm pore-size membrane filter. Soil samples were washed with sterile distilled water, and washings were similarly filtered, as mentioned for water samples. The filtered material was cultured on non-nutrient agar plates seeded with heat-killed Escherichia coli. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba. Finally, 26 isolates were successfully sequenced. According to culture and PCR methods, 54% of water and 100% of soil samples were contaminated with Acanthamoeba. Based on the sequencing data, genotypes T4 (47%), T5 (35.29%), T3 (11.76%), and T11 (5.88%) were identified in water samples. Genotypes T4 (66.6%), T5 (22.2%) and T15 (11.1%) were identified in water samples. Most isolates might present a potential health hazard for humans in this region. To the best of our knowledge, this is the first comprehensive survey of water and soil of recreational areas in northern Iran and the first report on identifying genotype T15 from soil sources.


Assuntos
Acanthamoeba , Solo , Humanos , Solo/parasitologia , Água/parasitologia , Irã (Geográfico) , Acanthamoeba/genética , Genótipo
7.
Parasitol Res ; 121(12): 3381-3392, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36258094

RESUMO

Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.


Assuntos
Helmintíase , Helmintos , Deficiências de Ferro , Gravidez , Criança , Animais , Feminino , Humanos , Solo/parasitologia , Helmintíase/complicações , Helmintíase/parasitologia , Ascaris lumbricoides , Trichuris , Ferro , Prevalência , Fezes/parasitologia
8.
Parasitol Res ; 121(12): 3641-3651, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36264508

RESUMO

By 2020, the World Health Organization and the Ghana Neglected Tropical Diseases programme intended to treat 75% and 100% of school-age children, respectively, during preventative chemotherapy (PCT), to control soil-transmitted helminths. The performance of PCT was assessed, and the factors associated with albendazole uptake in 2019 were determined. This study comprised secondary data (2019 PCT) and a community-based cross-sectional study conducted among 352 children aged from 7 to 14 years and enrolled with their caregivers. Logistic regression was used to determine the factors hindering or favouring the PCT uptake. According to surveillance data (2019 PCT), Krachi East Municipal reported coverage of 83% in schools and 40.9% for all children between 5 and 14 years. The cross-sectional data showed that the median child age was 11 years (IQR: 9-12). There was no gap in the estimates for coverage and uptake, which were both 90.9% (95%CI: 87.4-93.5%). Christians made up the majority of the caregivers (87.5%), and 48.0% had completed secondary or higher education. After controlling for potential confounders, caregiver religion (aOR = 0.07 95%CI: 0.01-0.36) and the perception of a child's PCT risk (aOR = 0.33 95%CI: 0.13-0.84) were the significant barriers of PCT uptake, whereas the child's age (aOR = 1.49 95%CI: 1.19-1.88) and the perception of a child's PCT's benefit (aOR = 10.26 95%CI: 2.57-40.95) were the significant facilitators among children 7-14 years old. Although the performance of PCT was high, the national treatment target was not attained. Intensive and focused health education is therefore needed to improve positive perceptions towards PCT for school-age children.


Assuntos
Helmintíase , Helmintos , Criança , Animais , Humanos , Adolescente , Estudos Transversais , Solo/parasitologia , Gana , Prevalência , Helmintíase/tratamento farmacológico , Helmintíase/prevenção & controle , Helmintíase/epidemiologia
9.
Nature ; 610(7933): 693-698, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36224389

RESUMO

Soils are the foundation of all terrestrial ecosystems1. However, unlike for plants and animals, a global assessment of hotspots for soil nature conservation is still lacking2. This hampers our ability to establish nature conservation priorities for the multiple dimensions that support the soil system: from soil biodiversity to ecosystem services. Here, to identify global hotspots for soil nature conservation, we performed a global field survey that includes observations of biodiversity (archaea, bacteria, fungi, protists and invertebrates) and functions (critical for six ecosystem services) in 615 composite samples of topsoil from a standardized survey in all continents. We found that each of the different ecological dimensions of soils-that is, species richness (alpha diversity, measured as amplicon sequence variants), community dissimilarity and ecosystem services-peaked in contrasting regions of the planet, and were associated with different environmental factors. Temperate ecosystems showed the highest species richness, whereas community dissimilarity peaked in the tropics, and colder high-latitudinal ecosystems were identified as hotspots of ecosystem services. These findings highlight the complexities that are involved in simultaneously protecting multiple ecological dimensions of soil. We further show that most of these hotspots are not adequately covered by protected areas (more than 70%), and are vulnerable in the context of several scenarios of global change. Our global estimation of priorities for soil nature conservation highlights the importance of accounting for the multidimensionality of soil biodiversity and ecosystem services to conserve soils for future generations.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Mapeamento Geográfico , Microbiologia do Solo , Solo , Animais , Conservação dos Recursos Naturais/métodos , Solo/parasitologia , Invertebrados , Archaea
10.
PLoS One ; 17(9): e0274702, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36107925

RESUMO

BACKGROUND: Ethiopia has set national targets for eliminating soil-transmitted helminths (STH) as public health problems by 2020 and for breaking their transmission by 2025 using periodic mass treatment of children in endemic areas. However, the status of STH infection among the adults living in the same communities remains unknown. The aim of this study, therefore, was to determine the prevalence and intensity of STH infections and associated factors among the household heads in the peri-urban areas of Jimma town, Oromia, Ethiopia. METHODS: A community-based cross-sectional study was conducted in five peri-urban kebeles (smallest administrative unit in Ethiopia) of Jimma town from May to July 2021. A semi-structured questionnaire was used to collect data on socio-demographic and predisposing factors. The Kato-Katz concentration technique was utilized to detect and quantify the STH in stool samples. Both bivariate and multivariate analyses were done. P-value <0.05 was considered statistically significant. RESULTS: A total of 376 household heads (19.9% women and 80.1% men) from peri-urban areas were included in the study. The overall STH prevalence was 18.1% (95% CI: 14.6-22.1) with A. lumbricoides being the predominant species (11.4%) followed by T. trichiura (7.2%) and hookworm (2.1%). Most of the STH positive household heads had single infections (85.3%) and light-intensity infections (88.5%). Wealth status (AOR = 2.7; 95% CI: 1.31-5.50, P = 0.007), hand washing habits before meals (AOR = 7.07; 95% CI: 1.79-27.88, p = 0.005), fingernails status (AOR = 2.99; 95% CI: 1.59-5.65, p = 0.001), and toilet facility type (AOR = 2.06; 95% CI: 1.13-3.76, p = 0.017) were found to have statistically significant associations with the STH infection. CONCLUSION: The findings of this study showed a nearly moderate level of STH prevalence among household heads in the peri-urban community. This could serve as an important reservoir for reinfection of the treated children and other at-risk groups in the community.


Assuntos
Helmintíase , Helmintos , Adulto , Animais , Criança , Estudos Transversais , Etiópia/epidemiologia , Características da Família , Feminino , Helmintíase/parasitologia , Humanos , Masculino , Prevalência , Fatores de Risco , Solo/parasitologia
11.
Pest Manag Sci ; 78(12): 5437-5443, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36057860

RESUMO

BACKGROUND: The bioinsecticidal action of entomopathogenic nematodes (EPNs) typically relies on their symbiosis with core bacteria. However, recent studies highlighted the possible involvement of other noncore species. We have recently isolated a novel Pseudomonas protegens strain as a major agent of septicaemia in larvae of the wax moth, Galleria mellonella, infected with a soil-dwelling Steinernema feltiae strain. The actual role of this bacterium in entomopathogenesis was investigated. RESULTS: The association of P. protegens with nematodes appeared to be robust, as supported by its direct and repeated isolation from both nematodes and insect larvae infected for several consecutive generations. The bacterium appeared to be well-adapted to the insect haemocoel, being able to proliferate rapidly after the injection of even a small amount of living cells [100 colony forming units (CFU)] to a larva, causing its fast death. The bacterium also was able to act by ingestion against G. mellonella larvae [median lethal concentration (LC50 ) = 4.0 × 107 CFU mL-1 ], albeit with a slower action, which supports the involvement of specific virulence factors (e.g. chitinases, Fit toxin) to overcome the intestinal barrier to the haemocoel. Varying levels of bacterial virulence were observed on diverse target Diptera and Lepidoptera. CONCLUSION: The soil-dwelling bacterium P. protegens appears to have evolved its own potential as a stand-alone entomopathogen, yet the establishment of an opportunistic association with entomoparasitic nematodes would represent a special competitive advantage. This finding contributes to a deeper understanding of the nematode-bacteria biocontrol agent complex and the deriving paradigm of their use as biological control agents. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Mariposas , Rabditídios , Animais , Controle Biológico de Vetores , Mariposas/parasitologia , Insetos , Larva/parasitologia , Solo/parasitologia , Bactérias
12.
PLoS Negl Trop Dis ; 16(9): e0010321, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36178964

RESUMO

BACKGROUND: Limited understanding exists about the interactions between malaria and soil-transmitted helminths (STH), their potential geographical overlap and the factors driving it. This study characterised the geographical and co-clustered distribution patterns of malaria and STH infections among vulnerable populations in sub-Saharan Africa (SSA). METHODOLOGY/PRINCIPAL FINDINGS: We obtained continuous estimates of malaria prevalence from the Malaria Atlas Project (MAP) and STH prevalence surveys from the WHO-driven Expanded Special Project for the Elimination of NTDs (ESPEN) from Jan 1, 2000, to Dec 31, 2018. Although, MAP provides datasets on the estimated prevalence of Plasmodium falciparum at 5km x 5km fine-scale resolution, we calculated the population-weighted prevalence of malaria for each implementation unit to ensure that both malaria and STH datasets were on the same spatial resolution. We incorporated survey data from 5,935 implementation units for STH prevalence and conducted the prevalence point estimates before and after 2003. We used the bivariate local indicator of spatial association (LISA analysis) to explore potential co-clustering of both diseases at the implementation unit levels among children aged 2-10 years for P. falciparum and 5-14 years for STH, living in SSA. Our analysis shows that prior to 2003, a greater number of SSA countries had a high prevalence of co-endemicity with P.falciparium and any STH species than during the period from 2003-2018. Similar prevalence and distribution patterns were observed for the co-endemicity involving P.falciparum-hookworm, P.falciparum-Ascaris lumbricoides and P.falciparum-Trichuris trichiura, before and after 2003. We also observed spatial variations in the estimates of the prevalence of P. falciparum-STH co-endemicity and identified hotspots across many countries in SSA with inter-and intra-country variations. High P. falciparum and high hookworm co-endemicity was more prevalent in West and Central Africa, whereas high P. falciparum with high A. lumbricoides and high P. falciparum with high T. trichiura co-endemicity were more predominant in Central Africa, compared to other sub-regions in SSA. CONCLUSIONS/SIGNIFICANCE: Wide spatial heterogeneity exists in the prevalence of malaria and STH co-endemicity within the regions and within countries in SSA. The geographical overlap and spatial co-existence of malaria and STH could be exploited to achieve effective control and elimination agendas through the integration of the vertical control programmes designed for malaria and STH into a more comprehensive and sustainable community-based paradigm.


Assuntos
Helmintíase , Helmintos , Malária Falciparum , Malária , África ao Sul do Saara/epidemiologia , Ancylostomatoidea , Animais , Criança , Fezes/parasitologia , Helmintíase/parasitologia , Humanos , Malária/complicações , Malária/epidemiologia , Malária Falciparum/epidemiologia , Prevalência , Solo/parasitologia
13.
PLoS Negl Trop Dis ; 16(9): e0010408, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36121895

RESUMO

Mass drug administration (MDA), targeted at school-aged children (SAC) is recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds, and research suggests that only treating SAC will not be sufficient to interrupt transmission of STH. In countries with endemic infection, such as Ethiopia, the coverage, community-groups targeted, and rates of reinfection will determine how effective MDA is in suppressing transmission in the long-term. In this paper, individually-linked longitudinal data from three epidemiological STH surveys conducted between November 2018 and November 2020 in the Wolaita region of Ethiopia are analysed to determine how STH prevalence and intensity changes according to individual level treatment data collected over two rounds of MDA. This study demonstrates that while community-wide MDA successfully reduces overall infection intensity across the villages treated, the observed levels of non-compliance to treatment by individuals acts to maintain levels of parasite abundance whereby transmission interruption is not possible at to, despite reasonable levels of MDA coverage in the communities studied (ranging from 65% to 84% of the village populations). This quantifies with substantial data the often-postulated difference between coverage (accepting treatment) and compliance (swallowing of treatment), the latter impacting the former to a previously unquantified level. The paper highlights the need to focus treatment to partially treated, or never treated groups of individuals within existing community wide MDA control activities to interrupt the transmission of STH, and to reduce the basic reproductive number, R0, of the parasites to less than unity in value.


Assuntos
Anti-Helmínticos , Helmintíase , Helmintos , Animais , Anti-Helmínticos/uso terapêutico , Criança , Etiópia/epidemiologia , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Humanos , Administração Massiva de Medicamentos , Prevalência , Reinfecção , Solo/parasitologia
14.
Front Immunol ; 13: 979727, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36159869

RESUMO

Background: Malaria and helminthic parasites are endemic in tropical countries, and co-infections might influence host-parasite interactions. In this community-based cross-sectional study, the effect that the presence of soil-transmitted helminths (STH) (Hookworm, Hymenolepis nana) and Schistosoma haematobium infections could have on the immunoglobulin (Ig) candidate protein of the malaria vaccine GMZ2 levels was evaluated. Methods: Blood, stool, and urine samples were collected from 5-15-year-old children to diagnose P. falciparum (Pf), STH, and Schistosoma haematobium, respectively. Identification and quantification of the parasite load of STH and S. haematobium were achieved by light microscopy. A polymerase chain reaction was carried out to detect submicroscopic infections of P. falciparum. Plasma levels of GMZ2 specific IgG and its subclasses were quantified by ELISA. Results: The median level of total IgG in individuals with co-infection with Pf/H. nana was significantly lower in the mono-infected group with Pf (p = 0.0121) or study participants without infection (p=0.0217). Similarly, the median level of IgG1 was statistically lower in Pf/H. nana group compared to Pf-group (p=0.0137). Equally, the Pf/H. nana infected individuals posted a lower level of IgG1 compared to Pf-group (p=0.0137) and IgG4 compared to the Pf-group (p=0.0144). Spearman rank correlation analyses indicated positive relationships between the densities of H. nana (ρ=0.25, p=0.015) and S. haematobium (ρ=0.36, p<0.0001). Conclusions: Hookworm and H. nana infections are associated with reduced GMZ2 specific IgG levels. This study shows the possible manipulation of immune responses by helminths for their survival and transmission, which may have serious implications for vaccine development and deployment in helminth-endemic regions.


Assuntos
Coinfecção , Helmintos , Infecções por Uncinaria , Vacinas Antimaláricas , Malária Falciparum , Malária , Parasitos , Adolescente , Ancylostomatoidea , Animais , Criança , Pré-Escolar , Coinfecção/parasitologia , Estudos Transversais , Humanos , Imunidade , Imunoglobulina G , Nigéria/epidemiologia , Plasmodium falciparum , Solo/parasitologia
15.
Epidemiol Infect ; 150: e151, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35983726

RESUMO

Soil-transmitted helminths, such as Ascaris lumbricoides, are the most prevalent parasites globally. Optimal anthelmintic treatment for A. lumbricoides in endemically infected communities is challenged by several host-related and environmental factors influencing infection acquisition. We assessed the risk of A. lumbricoides (re)infection after treatment in a Venezuelan rural community. Individual merthiolate-iodine-formaldehyde-fixed faecal samples were collected from 224 persons before a single-dose pyrantel treatment and at 1, 3, 6, 9 and 15 months after treatment. Effects of age, sex and socioeconomic status (SES) on A. lumbricoides prevalence, eggs/gram faeces (EPG) and infection (re)acquisition were assessed using both generalised linear mixed-effects models and survival analysis. Pre-treatment A. lumbricoides prevalence was 39.7%. Higher prevalence was associated with younger age and lower SES. Higher EPG values were observed among young children. Median time to A. lumbricoides infection was six months after treatment: at 1, 3, 6, 9 and 15 months post-treatment, cumulative incidence was 6.7%, 18.9%, 34.6%, 42.2%, and 52.6%, respectively. Younger age, lower SES, and pre-treatment A. lumbricoides infection status showed significantly elevated hazard ratios. Mass drug administration protocols would benefit from considering these factors in selective treatment strategies and possibly more than just annual or biannual treatments in the target population.


Assuntos
Ascaríase , Helmintíase , Animais , Ascaríase/tratamento farmacológico , Ascaríase/epidemiologia , Ascaríase/parasitologia , Ascaris lumbricoides , Criança , Pré-Escolar , Fezes/parasitologia , Helmintíase/epidemiologia , Helmintíase/parasitologia , Humanos , Prevalência , População Rural , Solo/parasitologia , Venezuela/epidemiologia
16.
BMC Pediatr ; 22(1): 477, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35932006

RESUMO

BACKGROUND: Schistosomiasis and soil-transmitted helminthiasis (STHs) are the major public health problem in the world especially in school age children. Therefore, this study aimed to determine the burden of soil transmitted helminths and Schistosoma mansoni among Ambesame primary school children, North-West Ethiopia. METHOD: A cross sectional study was carried out at Ambasame primary school children from March to May, 2019. Study participants were selected using systematic random sampling technique. Socio-demographic characteristics and other factors were collected using structured questionnaire. Moreover, stool samples were examined microscopically using wet mount and formol ether concentration techniques. Data were entered and analyzed using SPSS version 20. Logistic regression analysis was done to investigate the association between dependent and independent variables. P-value less than 0.05 was considered as statistically significant. RESULT: The overall prevalence of intestinal parasites was 117(31.2%). The prevalence of soil-transmitted helminthes and S.mansoni was 110 (29.3%) using formol ether concentration technique. The most predominant parasite was S. mansoni (10.7%), followed by hookworm (5.6%). Multivariate logistic regression analysis revealed that, helminthic infection was associated with children less than 7 years of age (P-value = 0.019, AOR = 3.29, 95% CI (1.21-8.91)); fathers who are able to read and write (P-value< 0.001, AOR = 5.4, 95% CI (2.37-12.33)); absence of latrine (P-value = 0.016, AOR = 12.96, 95% CI (1.60-104.87)) and untrimmed nail (P-value = 0.043, AOR = 2.09, 95% CI (1.02-4.27)). CONCLUSION: This study revealed that the prevalence of intestinal helminthes among Ambasame primary school children was relatively high. The lower educational status of father, absence of latrine and untrimmed finger nail showed statistically significant association with intestinal helminthic infection. This indicates the school community, health offices and other stakeholders should plan a strategy to tackle problems associated with sanitary condition. Furthermore, Health policy makers, healthcare workers and health extension workers should enhance their effort of awareness creation for school children, parents, school community about personal hygiene, environmental sanitation, intestinal parasites transmission, prevention and control. Moreover, mass deworming of school children and periodic screening for parasitic infection should be done.


Assuntos
Helmintíase , Helmintos , Enteropatias Parasitárias , Esquistossomose mansoni , Animais , Criança , Estudos Transversais , Éteres , Etiópia/epidemiologia , Formaldeído , Helmintíase/epidemiologia , Humanos , Enteropatias Parasitárias/epidemiologia , Prevalência , Fatores de Risco , Esquistossomose mansoni/epidemiologia , Instituições Acadêmicas , Solo/parasitologia
17.
PLoS Negl Trop Dis ; 16(8): e0010593, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35917364

RESUMO

BACKGROUND: Periodic administration of anthelmintic drugs is a cost-effective intervention for morbidity control of soil-transmitted helminth (STH) infections. However, with programs expanding, drug pressure potentially selecting for drug-resistant parasites increases. While monitoring anthelmintic drug efficacy is crucial to inform country control program strategies, different factors must be taken into consideration that influence drug efficacy and make it difficult to standardize treatment outcome measures. We aimed to identify suitable approaches to assess and compare the efficacy of different anthelmintic treatments. METHODOLOGY: We built an individual participant-level database from 11 randomized controlled trials and two observational studies in which subjects received single-agent or combination therapy, or placebo. Eggs per gram of stool were calculated from egg counts at baseline and post-treatment. Egg reduction rates (ERR; based on mean group egg counts) and individual-patient ERR (iERR) were utilized to express drug efficacy and analyzed after log-transformation with a linear mixed effect model. The analyses were separated by follow-up duration (14-21 and 22-45 days) after drug administration. PRINCIPAL FINDINGS: The 13 studies enrolled 5,759 STH stool-positive individuals; 5,688 received active medication or placebo contributing a total of 11,103 STH infections (65% had two or three concurrent infections), of whom 3,904 (8,503 infections) and 1,784 (2,550 infections) had efficacy assessed at 14-21 days and 22-45 days post-treatment, respectively. Neither the number of helminth co-infections nor duration of follow-up affected ERR for any helminth species. The number of participants treated with single-dose albendazole was 689 (18%), with single-dose mebendazole 658 (17%), and with albendazole-based co-administrations 775 (23%). The overall mean ERR assessed by day 14-21 for albendazole and mebendazole was 94.5% and 87.4%, respectively on Ascaris lumbricoides, 86.8% and 40.8% on hookworm, and 44.9% and 23.8% on Trichuris trichiura. The World Health Organization (WHO) recommended criteria for efficacy were met in 50%, 62%, and 33% studies of albendazole for A. lumbricoides, T. trichiura, and hookworm, respectively and 25% of mebendazole studies. iERR analyses showed similar results, with cure achieved in 92% of A. lumbricoides-infected subjects treated with albendazole and 93% with mebendazole; corresponding figures for hookworm were 70% and 17%, and for T. trichiura 22% and 20%. CONCLUSIONS/SIGNIFICANCE: Combining the traditional efficacy assessment using group averages with individual responses provides a more complete picture of how anthelmintic treatments perform. Most treatments analyzed fail to meet the WHO minimal criteria for efficacy based on group means. Drug combinations (i.e., albendazole-ivermectin and albendazole-oxantel pamoate) are promising treatments for STH infections.


Assuntos
Anti-Helmínticos , Helmintíase , Helmintos , Infecções por Uncinaria , Tricuríase , Albendazol/uso terapêutico , Ancylostomatoidea , Animais , Anti-Helmínticos/uso terapêutico , Helmintíase/tratamento farmacológico , Infecções por Uncinaria/tratamento farmacológico , Humanos , Mebendazol/uso terapêutico , Solo/parasitologia , Tricuríase/tratamento farmacológico , Trichuris
18.
PLoS One ; 17(8): e0272600, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36006929

RESUMO

Much effort has been devoted by the World Health Organization (WHO) to eliminate soil-transmitted helminth (STH) infections by 2030 using mass drug administration targeted at particular risk groups alongside the availability to access water, sanitation and hygiene services. The targets set by the WHO for the control of helminth infections are typically defined in terms of the prevalence of infection, whereas the standard formulation of STH transmission models typically describe dynamic changes in the mean-worm burden. We develop a prevalence-based deterministic model to investigate the transmission dynamics of soil-transmitted helminthiasis in humans, subject to continuous exposure to infection over time. We analytically determine local stability criteria for all equilibria and find bifurcation points. Our model predicts that STH infection will either be eliminated (if the initial prevalence value, y(0), is sufficiently small) or remain endemic (if y(0) is sufficiently large), with the two stable points of endemic infection and parasite eradication separated by a transmission breakpoint. Two special cases of the model are analysed: (1) the distribution of the STH parasites in the host population is highly aggregated following a negative binomial distribution, and (2) no density-dependent effects act on the parasite population. We find that disease extinction is always possible for Case (1), but it is not so for Case (2) if y(0) is sufficiently large. However, by introducing stochastic perturbation into the deterministic model, we discover that chance effects can lead to outcomes not predicted by the deterministic model alone, with outcomes highly dependent on the degree of worm clumping, k. Specifically, we show that if the reproduction number and clumping are sufficiently bounded, then stochasticity will cause the parasite to die out. It follows that control of soil-transmitted helminths will be more difficult if the worm distribution tends towards clumping.


Assuntos
Helmintíase , Helmintos , Animais , Fezes/parasitologia , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Humanos , Administração Massiva de Medicamentos , Prevalência , Saneamento , Solo/parasitologia
19.
Sci Rep ; 12(1): 13935, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35978014

RESUMO

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.


Assuntos
Helmintíase , Helmintos , Infecções por Uncinaria , Ancylostomatoidea , Animais , Ascaris lumbricoides , Criança , Fezes/parasitologia , Helmintíase/tratamento farmacológico , Infecções por Uncinaria/epidemiologia , Humanos , Prevalência , Solo/parasitologia , Trichuris
20.
Int J Parasitol ; 52(10): 637-646, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36007621

RESUMO

Dog parks provide an ideal urban space where dogs and their owners can exercise, play, and socialise in a safe environment. However, these parks can also increase the risk of exposure to a series of infectious agents including canine soil-transmitted helminths (cSTHs) such as hookworms, roundworms, Strongyloides stercoralis, and Trichuris vulpis, which are endemic to Australia. In this study, we collected 1581 canine faecal samples in 190 urban parks across Australia and subjected these to faecal floatation and multiplex real-time PCRs (qPCR) to detect a range of cSTHs. In total, 44.2% of the parks sampled were contaminated with at least one species of cSTH, with hookworms being the most prevalent parasites (10.2%) followed by Trichuris spp. (1.3%) and Strongyloides spp. (1.2%). This is the first large-scale study investigating the contamination of urban parks with cSTHs in Australia, and the first nation-wide study to demonstrate the occurrence of Strongyloides spp. in canine faecal samples from urban areas in the country. This study reveals a high rate of contamination with cSTHs in dog parks in urban Australia, most of which having proven zoonotic potential. Preventive measures, including awareness-raising educational programmes promoting responsible pet ownership, should be encouraged to minimise the health risks associated with cSTHs for both dogs and humans.


Assuntos
Doenças do Cão , Helmintos , Enteropatias Parasitárias , Cães , Animais , Humanos , Parques Recreativos , Solo/parasitologia , Enteropatias Parasitárias/parasitologia , Prevalência , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Helmintos/genética , Fezes/parasitologia , Trichuris , Fatores de Risco
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