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1.
Parasit Vectors ; 17(1): 99, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38429804

RESUMEN

BACKGROUND: Soil-transmitted helminths (STH) infect more than a quarter of the world's human population. In the absence of vaccines for most animal and human gastrointestinal nematodes (GIN), treatment of infections primarily relies on anthelmintic drugs, while resistance is a growing threat. Therefore, there is a need to find alternatives to current anthelmintic drugs, especially those with novel modes of action. The present work aimed to study the composition and anthelmintic activity of Combretum mucronatum leaf extract (CMLE) by phytochemical analysis and larval migration inhibition assays, respectively. METHODS: Combretum mucronatum leaves were defatted with petroleum ether and the residue was extracted by ethanol/water (1/1) followed by freeze-drying. The proanthocyanidins and flavonoids were characterized by thin layer chromatography (TLC) and ultra-high performance liquid chromatography (UPLC). To evaluate the inhibitory activity of this extract, larval migration assays with STH and GIN were performed. For this purpose, infective larvae of the helminths were, if necessary, exsheathed (Ancylostoma caninum, GIN) and incubated with different concentrations of CMLE. RESULTS: CMLE was found to be rich in flavonoids and proanthocyanidins; catechin and epicatechin were therefore quantified for standardization of the extract. Data indicate that CMLE had a significant effect on larval migration. The effect was dose-dependent and higher concentrations (1000 µg/mL) exerted significantly higher larvicidal effect (P < 0.001) compared with the negative control (1% dimethyl sulfoxide, DMSO) and lower concentrations (≤ 100 µg/ml). Infective larvae of Ascaris suum [half-maximal inhibitory concentration (IC50) = 5.5 µg/mL], Trichuris suis (IC50 = 7.4 µg/mL), and A. caninum (IC50 = 18.9 µg/mL) were more sensitive to CMLE than that of Toxocara canis (IC50 = 310.0 µg/mL), while infective larvae of Toxocara cati were largely unaffected (IC50 > 1000 µg/mL). Likewise, CMLE was active against most infective larvae of soil-transmitted ruminant GIN, except for Cooperia punctata. Trichostrongylus colubriformis was most sensitive to CMLE (IC50 = 2.1 µg/mL) followed by Cooperia oncophora (IC50 = 27.6 µg/mL), Ostertagia ostertagi (IC50 = 48.5 µg/mL), Trichostrongylus axei (IC50 = 54.7 µg/mL), Haemonchus contortus (IC50 = 145.6 µg/mL), and Cooperia curticei (IC50 = 156.6 µg/mL). CONCLUSIONS: These results indicate that CMLE exhibits promising anthelmintic properties against infective larvae of a large variety of soil-transmitted nematodes.


Asunto(s)
Antihelmínticos , Combretum , Helmintos , Nematodos , Proantocianidinas , Trichostrongyloidea , Animales , Humanos , Combretum/química , Proantocianidinas/farmacología , Proantocianidinas/química , Larva , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antihelmínticos/farmacología , Rumiantes , Flavonoides/farmacología , Fitoquímicos/farmacología
2.
Parasite Immunol ; 46(1): e13015, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37846743

RESUMEN

Soil-transmitted helminths (STHs) parasitic infection is known as one of the most common infections around the world affecting more than a quarter of the world's population. The relationship between STH infections and micronutrient deficiencies are closely related and often coexist among the affected population. The study, therefore, aimed to summarise the available literature focusing on the effect of zinc status/deficiency or supplementation on STH infection or reinfection in children. For this purpose, we adopted a systematic approach and searched the existing literature on PubMed, Scopus, and Cochrane Library databases. A search term was entered to retrieve the available data. A total of 12 articles were included in this review after applying the inclusion/exclusion criteria. Most of the included studies reported a lower zinc status in children affected with any parasitic infection. Regarding the effect of zinc status and supplementation on parasitic infection in children, we found only a few studies (n = 4) with inconsistent result findings. This review reported that children infected with STH have lower zinc levels; however, a limited number of studies showed the effect of zinc supplements on the risk of STH warrants the need for further studies in this regard.


Asunto(s)
Helmintiasis , Helmintos , Niño , Animales , Humanos , Zinc , Suelo/parasitología , Helmintiasis/complicaciones , Helmintiasis/epidemiología , Suplementos Dietéticos , Prevalencia
3.
PLoS Negl Trop Dis ; 17(11): e0011656, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37930980

RESUMEN

BACKGROUND: In Bangladesh, preventive chemotherapy targeting soil-transmitted helminth (STH) infections in school-age children has been implemented since 2008. To evaluate the success of this strategy, surveys were conducted between 2017 and 2020 in 10 out of 64 districts. We estimate the geographic distribution of STH infections by species at high spatial resolution, identify risk factors, and estimate treatment needs at different population subgroups. METHODOLOGY: Bayesian geostatistical models were fitted to prevalence data of each STH species. Climatic, environmental, and socioeconomic predictors were extracted from satellite images, open-access, model-based databases, and demographic household surveys, and used to predict the prevalence of infection over a gridded surface at 1 x 1 km spatial resolution across the country, via Bayesian kriging. These estimates were combined with gridded population data to estimate the number of required treatments for different risk groups. PRINCIPAL FINDINGS: The population-adjusted prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm across all ages is estimated at 9.9% (95% Bayesian credible interval: 8.0-13.0%), 4.3% (3.0-7.3%), and 0.6% (0.4-0.9%), respectively. There were 24 out of 64 districts with an estimated population-adjusted STH infection prevalence above 20%. The proportion of households with improved sanitation showed a statistically important, protective association for both, A. lumbricoides and T. trichiura prevalence. Precipitation in the driest month of the year was negatively associated with A. lumbricoides prevalence. High organic carbon concentration in the soil's fine earth fraction was related to a high hookworm prevalence. Furthermore, we estimated that 30.5 (27.2; 36.0) million dosages of anthelmintic treatments for school-age children were required per year in Bangladesh. CONCLUSIONS/SIGNIFICANCE: For each of the STH species, the prevalence was reduced by at least 80% since treatment was scaled up more than a decade ago. The current number of deworming dosages could be reduced by up to 61% if the treatment strategy was adapted to the local prevalence.


Asunto(s)
Helmintiasis , Helmintos , Infecciones por Uncinaria , Niño , Animales , Humanos , Suelo , Teorema de Bayes , Bangladesh/epidemiología , Helmintiasis/tratamiento farmacológico , Helmintiasis/epidemiología , Helmintiasis/prevención & control , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Ancylostomatoidea , Ascaris lumbricoides , Prevalencia , Heces
4.
Am J Trop Med Hyg ; 109(3): 656-666, 2023 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-37549897

RESUMEN

The forcibly displaced Myanmar nationals (FDMNs) known as Rohingya refugees are the largest group of stateless individuals globally. According to the emergencies humanitarian actors at the United Nations Office for the Coordination of Humanitarian Affairs, the worldwide refugee crisis involving FDMNs is intensifying at the fastest rate in history. Growing public health demands are being exacerbated by current difficulties in addressing poor access to health services, severe food shortages, and a lack of adequate housing. Infectious diseases constitute a major public health emergency in this vulnerable population. A study was carried out in FDMN children to investigate common soil-transmitted helminth (STH) infection at the time of enrollment and prospectively followed-up to 12 months after 2 doses albendazole treatment. At baseline, the prevalence of STH infection with at least one species was found to be 91.7% and 87.3% for Kato-Katz (KK) and quantitative polymerase chain reaction (qPCR) methods, respectively. Similarly, for follow-up children, the overall infection rate was 95.3% and 91.5%, respectively. Trichuris trichiura was the most predominant STH infection by both KK (baseline 87%, follow-up 89.1%) and qPCR (baseline 77.5%, follow-up 82.9%). The overall prevalence of stunting in the children was 37.8% at baseline and rose to 51.3% at 12 months. Alpha-1 antitrypsin (r = 0.13, P = 0.01) and myeloperoxidase (r = 0.12, P = 0.01) levels showed a positive correlation with Aascaris lumbricoides egg count per gram at baseline. An in-depth investigation is urgently needed to identify the underlying protective measures and the root cause of STH infections to improve the health of FDMN children.


Asunto(s)
Helmintiasis , Helmintos , Animales , Niño , Humanos , Albendazol/uso terapéutico , Suelo/parasitología , Prevalencia , Bangladesh/epidemiología , Mianmar/epidemiología , Heces/parasitología , Helmintiasis/tratamiento farmacológico , Helmintiasis/epidemiología , Helmintiasis/parasitología
5.
PLoS Negl Trop Dis ; 17(5): e0011071, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37196017

RESUMEN

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.


Asunto(s)
Helmintiasis , Helmintos , Animales , Humanos , Ascaris lumbricoides , Heces , Helmintiasis/tratamiento farmacológico , Helmintiasis/diagnóstico , Sensibilidad y Especificidad , Suelo , Trichuris
6.
Fitoterapia ; 166: 105467, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36893925

RESUMEN

Active principles extracted from plants, such as essential oils, have been commonly described in the literature as therapeutic targets for numerous pathological conditions. Cannabis sativa, which has an ancient and peculiar history, has been used for various purposes, from recreational to compounds of pharmacotherapeutic and industrial importance, such as pesticides based on this plant. It is a plant that contains approximately 500 described cannabinoid compounds and is the target of in vitro and in vivo studies at different locations. This review clarifies the role of cannabinoid compounds in parasitic infections caused by helminths and protozoa. In addition, this study briefly presented the use of C. sativa constituents in the formulation of pesticides for vector control, as the latter topic is justified by the economic burden faced by several regions where vector-borne diseases are a troubling reality. Studies involving cannabis compounds with pesticidal potential should be encouraged, especially those that evaluate their effectiveness against the different life cycles of insects, seeking to interrupt vector proliferation after egg laying. Actions aimed at the management and cultivation of plant species with ecologically correct pharmacotherapeutic and pesticide potentials are becoming urgent.


Asunto(s)
Cannabinoides , Cannabis , Helmintos , Animales , Estructura Molecular , Plantas , Insectos Vectores
7.
Ann Parasitol ; 68(3): 421-434, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36502541

RESUMEN

Bison bonasus (Linnaeus, 1758) and B. bison (Linnaeus, 1758) are mammals placed in the Red Book of the International Union for Conservation of Nature. Populations of those species of animals are under threat of extinction. Therefore, developing practical measures for their protection is of great significance. However, one way of improving the population of bisons is integrated control of their helminths. The article generalizes the data about the helminth fauna of B. bonasus and B. bison, as well as data on relatively medicinal plants with anthelmintic properties. The results of the analysis indicate the existence of more effective medicinal plants that could be used to develop novel anthelmintic drugs. Less effective anthelmintic plants may be consumed by animals in pastures or with hay in the conditions of stable maintenance. Helminths in bison populations should be controlled using plant-based anthelmintic drugs taking into account infections in animals in particular herds of bisons by more or less dangerous helminths.


Asunto(s)
Bison , Helmintos , Plantas Medicinales , Animales , Bison/parasitología
8.
Sci Rep ; 12(1): 22313, 2022 12 24.
Artículo en Inglés | MEDLINE | ID: mdl-36566272

RESUMEN

Despite having a high risk of soil-transmitted helminths (STHs) infection, no national level study has been conducted to assess incidence and correlates of STHs in Nepal. Thus, we hypothesized that micronutrients and social status are linked with incidence of STHs infection among 6-59 months children and 15-49 years non-pregnant women in Nepal and Kato-Katz technique was adopted to measure the type and intensity of STHs infections using fresh stool specimens and venous blood was used to examine micronutrients biomarkers. Anthropometric measurements such as height and weight, sociodemographic and health status were determined using structured questionnaire. Logistic regression was used to assess unadjusted and adjusted odds ratio (AOR) and the 95% CIs of ORs. The bivariate association of STHs was assessed with the covariates variables. Overall, 12% children and 19% non-pregnant women had STHs infection; A. lumbricoides was the predominant helminth in both study participants. In multivariate model; age, ethnicity, anaemia and zinc deficiency were associated with STHs infections in children. Similarly, higher odds of STHs occurrence was observed among non-pregnant women with vitamin A deficiency. Findings from this study suggest that high-risk population, with a focus on those of lower socioeconomic status should be on priority of deworming program, nutrition intervention, and mass administration of preventive chemotherapy and sanitation champions supplement to reduce the STHs infections in Nepal.


Asunto(s)
Helmintiasis , Helmintos , Oligoelementos , Femenino , Animales , Humanos , Niño , Micronutrientes , Suelo/parasitología , Nepal/epidemiología , Helmintiasis/parasitología , Prevalencia , Heces/parasitología
9.
PLoS Negl Trop Dis ; 16(10): e0010895, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36279298

RESUMEN

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.


Asunto(s)
Helmintiasis , Helmintos , Infecciones por Uncinaria , Humanos , Perros , Animales , Suelo/parasitología , Teorema de Bayes , Australia/epidemiología , Ascaris lumbricoides , Trichuris , Helmintiasis/epidemiología , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/veterinaria , Ancylostomatoidea , Ancylostoma , Zoonosis/epidemiología , Prevalencia , Heces/parasitología
10.
PLoS Negl Trop Dis ; 16(8): e0010593, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35917364

RESUMEN

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.


Asunto(s)
Antihelmínticos , Helmintiasis , Helmintos , Infecciones por Uncinaria , Tricuriasis , Albendazol/uso terapéutico , Ancylostomatoidea , Animales , Antihelmínticos/uso terapéutico , Helmintiasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Humanos , Mebendazol/uso terapéutico , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Trichuris
11.
PLoS Negl Trop Dis ; 16(4): e0010298, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35377878

RESUMEN

BACKGROUND: Neglected Tropical Diseases (NTDs) such as soil transmitted helminths (STH) and human rabies represent a significant burden to health in East Africa. Control and elimination remains extremely challenging, particularly in remote communities. Novel approaches, such as One Health based integrated interventions, are gaining prominence, yet there is more to be learned about the ways in which social determinants affect such programmes. METHODOLOGY: In 2015 a mixed method qualitative study was conducted in northern Tanzania to determine community perceptions towards integrated delivery of two distinct healthcare interventions: treatment of children for STH and dog vaccination for rabies. In order to assess the effectiveness of the integrated approach, villages were randomly allocated to one of three intervention arms: i) Arm A received integrated mass drug administration (MDA) for STH and mass dog rabies vaccination (MDRV); ii) Arm B received MDA only; iii) Arm C received MDRV only. PRINCIPLE FINDINGS: Integrated interventions were looked upon favourably by communities with respondents in all arms stating that they were more likely to either get their dogs vaccinated if child deworming was delivered at the same time and vice versa. Participants appreciated integrated interventions, due to time and cost savings and increased access to essential health care. Analysis of qualitative data allowed deeper exploration of responses, revealing why people appreciated these benefits as well as constraints and barriers to participation in integrated programmes. CONCLUSIONS/SIGNIFICANCE: An interdisciplinary One Health approach that incorporates qualitative social science can provide key insights into complex local perceptions for integrated health service delivery for STH and human rabies. This includes providing insights into how interventions can be improved while acknowledging and addressing critical issues around awareness, participation and underlying health disparities in remote pastoralist communities.


Asunto(s)
Helmintiasis , Helmintos , Salud Única , Rabia , Animales , Perros , Helmintiasis/tratamiento farmacológico , Humanos , Administración Masiva de Medicamentos , Enfermedades Desatendidas/tratamiento farmacológico , Rabia/tratamiento farmacológico , Rabia/prevención & control , Rabia/veterinaria , Suelo/parasitología , Tanzanía
12.
Ann Parasitol ; 68(4): 645-656, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36800645

RESUMEN

This review article provides more information about the incidence of helminths affect the gastrointestinal tracts of poultry in different countries, life cycle, clinical picture, diagnosis, and prevention and control measures of such infections. Backyard and deep litter production systems show higher helminth infections than cage system. Moreover, the incidence of helminth infection is more common in tropical countries of Africa and Asia than of European ones due to the suitability of environment and management conditions. Nematodes and cestodes are the most common gastrointestinal helminths of avian species, followed by trematodes. The life cycles of helminths may be direct or indirect, but the infection is usually through faecal-oral route. Affected birds show general signs, low production performance parameters, and even death due to intestinal obstruction and rupture. Lesions of the infected birds reveal catarrhal to haemorrhagic enteritis according to the severity of infection. Diagnosis of affection is mainly based on post mortem examination or microscopic detection of eggs or parasites. As internal parasites adversely affect the host causing poor feed utilization and low performance, thus intervention control strategies are urgent. Prevention and control strategies are relied on application of strict biosecurity measures, eradication of intermediate hosts, early routine diagnosis, and continuous application of specific anthelmintic drugs. Deworming using herbal medicine is recent and successful and may be good alternative to chemicals. In conclusion, helminth infections of poultry remain a major hurdle against the profitable production in poultry producing countries and necessary preventive and control measures should be strictly applied by poultry producers.


Asunto(s)
Infecciones por Cestodos , Helmintiasis Animal , Helmintos , Enfermedades de las Aves de Corral , Animales , Aves de Corral , Helmintiasis Animal/parasitología , Tracto Gastrointestinal/parasitología , Infecciones por Cestodos/veterinaria , Enfermedades de las Aves de Corral/epidemiología
13.
Int J Parasitol ; 51(13-14): 1243-1253, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34774540

RESUMEN

The major soil-transmitted helminths that infect humans are the roundworms, whipworms and hookworms. Soil-transmitted helminth infections rank among the most important neglected tropical diseases in terms of morbidity, and almost one billion people are still infected with at least one species. While anthelmintic drugs are available, they do not offer long term protection against reinfection, precipitating the need for vaccines that provide long-term immunologic defense. Vaccine discovery and development is in advanced clinical development for hookworm infection, with a bivalent human hookworm vaccine in clinical trials in Brazil and Africa, but is in its infancy for both roundworm (ascariasis) and whipworm (trichuriasis) infections. One of the greatest hurdles to developing soil-transmitted helminth vaccines is the potent immunoregulatory properties of these helminths, creating a barrier to the induction of meaningful long-term protective immunity. While challenging for vaccinologists, this phenomenon presents unique opportunities to develop an entirely new class of anti-inflammatory drugs that capitalise on these immunomodulatory strategies. Epidemiologic studies and clinical trials employing experimental soil-transmitted helminth challenge models, when coupled with findings from animal models, show that at least some soil-transmitted helminth-derived molecules can protect against the onset of autoimmune, allergic and metabolic disorders, and several natural products with the desired bioactivity have been isolated and tested in pre-clinical settings. The yin and yang of soil-transmitted helminth infections reflect both the urgency for effective vaccines and the potential for new immunoregulatory molecules from parasite products.


Asunto(s)
Ascariasis , Helmintiasis , Helmintos , Infecciones por Uncinaria , Nematodos , Tricuriasis , Vacunas , Ancylostomatoidea , Animales , Helmintiasis/tratamiento farmacológico , Helmintiasis/prevención & control , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/prevención & control , Humanos , Prevalencia , Suelo/parasitología , Trichuris
14.
Infect Dis Poverty ; 10(1): 116, 2021 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-34507609

RESUMEN

BACKGROUND: Soil-transmitted helminths (STH) infections still present a global health problem. Mass drug administration (MDA) is a widely applied strategy to reduce morbidity and mortality caused by STH. Yet, this approach has some shortcomings. In this study, we analyzed the impact of a multi-intervention integrated deworming approach including MDA, health education (HE), and environmental sanitation improvements (ESI) for sustained STH control in Jiangsu Province of China that was applied from 1989 to 2019. METHODS: Data, including infection rate of STH, medications used, coverage of the medication, non-hazardous lavatory rate, and household piped-water access rate in rural areas, and actions related to HE and ESI were collected (from archives) and analyzed in this retrospective descriptive study. Pearson's correlation analysis was applied to test correlations. RESULTS: There was a dramatic decline in the infection rate of STH from 1989 (59.32%) to 2019 (0.12%). From 1995 to 1999, MDA and HE were recommended in rural areas. A negative correlation was observed between infection rate and medication from 1994 to 1998 (r = - 0.882, P = 0.048). From 2000 to 2005, targeted MDA was given to high-risk populations with HE continuously promoting good sanitation behaviors. From 2006 to 2014, targeted MDA + HE and ESI were used to consolidate the control effect. ESI was strengthened from 2006, and a negative correlation was observed between the coverage rate of the non-hazardous lavatory and the infection rate from 2006 to 2019 (r = - 0.95, P < 0.001). The targeted MDA was interrupted in 2015, while continuous efforts like HE and ESI contributed in sustaining STH control. CONCLUSIONS: Multi-intervention integrated deworming strategy contributes to the reduction of STH infections. This approach is a valuable example of how different interventions can be integrated to promote durable STH control.


Asunto(s)
Antihelmínticos/uso terapéutico , Helmintiasis/tratamiento farmacológico , Helmintiasis/epidemiología , Helmintos/aislamiento & purificación , Saneamiento/métodos , Suelo/parasitología , Animales , China/epidemiología , Estudios Transversales , Helmintiasis/prevención & control , Helmintiasis/transmisión , Helmintos/clasificación , Humanos , Prevalencia , Estudios Retrospectivos
15.
Front Public Health ; 9: 645522, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34336756

RESUMEN

Background: Soil-transmitted helminths (STH) are among the most common parasitic infections globally, disproportionately affecting children. Treatment of STH in Kenya is often targeted at preschool (PSAC) and school aged (SAC) children delivered through annual mass drug administration (MDA) in primary schools. Understanding group-specific prevalence and dynamics between treatment and coverage is critical for continued treatment success. This study aims to provide detailed information on group-specific infection prevalence and relative reductions (RR), and their relationships with treatment coverage over time. Additionally, it aims to quantify the correlation between the observed school level infection prevalence and treatment coverage. Methods: Secondary analysis of existing data collected between 2012 and 2018 by the monitoring and evaluation (M&E) program of the National School-Based Deworming (NSBD) program was used. The M&E program conducted surveys utilizing cross-sectional study design, at four survey time points, in a nationally-representative sample of schoolchildren across counties in Kenya. In each participating school, the program randomly sampled 108 children per school, of both groups. Infection prevalence was estimated using binomial regression, RR in prevalence using multivariable mixed effects model, statistical correlations using structural equation modeling, and change-point-analysis using the binary segmentation algorithm. Results: Overall, STH prevalence for PSAC was 33.7, 20.2, 19.0, and 17.9% during Year 1 (Y1), Year 3 (Y3), Year 5 (Y5), and Year 6 (Y6) surveys, respectively with an overall RR of 46.9% (p = 0.001) from Y1 to Y6. Similarly, overall STH prevalence for SAC was 33.6, 18.4, 14.7, and 12.5% during Y1, Y3, Y5, and Y6 surveys, respectively with an overall RR of 62.6% (p < 0.001). An overall (all time points) significant but very weak negative correlation was found between treatment coverage and undifferentiated STH prevalence (r = -0.144, p = 0.002) among PSAC but not in SAC. Further, we observed inter-county heterogeneity variation in infection prevalence, RR, as well as correlations. Conclusion: The analysis showed that after six rounds of MDA, prevalence of STH has significantly declined among both groups of children, however not to a point where it is not a public health problem (below 1%). The analysis, additionally established an overall significant but weak negative correlation between treatment coverage and prevalence, indicating that the current treatment coverage might not be sufficient to drive the overall STH prevalence to below 1%. These findings will allow STH control programs in Kenya to make decisions that will accelerate the attainment of STH elimination as a public health problem.


Asunto(s)
Helmintos , Suelo , Animales , Niño , Preescolar , Estudios Transversales , Humanos , Kenia/epidemiología , Prevalencia , Instituciones Académicas
16.
Parasitol Res ; 120(9): 3215-3227, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34337681

RESUMEN

Persicaria strigosa (R.Br.) Nakai. (Family Polygonaceae) is an important plant of Assam, having several ethnobotanical uses. Tribal communities consume leaf extracts to cure helminth infection. The present study investigated the antioxidant, phytochemicals, and anthelmintic activity of P. strigosa. Total phenolic and flavonoid contents were estimated following standard methods. Antioxidant properties were analyzed by TAC, FRAP, DPPH, ABTS, and TBARS assays. Anthelmintic activity of plant was investigated in Paramphistomum sp. treated with 5 mg/mL, and paralysis and death times were recorded. The most potent solvent extract was performed GC-MS analysis to identify the phytocompounds. Plant extract-treated parasites were further analyzed for biochemical changes. Additionally, molecular docking was performed to study the binding affinities between phytocompounds and enzymes. P. strigosa showed rich phenolics, flavonoids, and antioxidant properties. Ethyl acetate and methanolic extracts showed more powerful antioxidant properties than other extracts. In vitro anthelmintic study found ethyl acetate and diethyl ether the most active extracts. Treated parasites showed a significant decrease in enzyme activity. The highest inhibition was observed in AchE, followed by MDH, LDH, ALP, and ACP. GC-MS study identified 12 probable compounds from the ethyl acetate extract of P. strigosa. Molecular docking showed the strongest binding affinity between the phytocompounds and AchE enzyme (- 7.6 kcal/mol). Overall, compounds C6, C7, and C12 showed better binding affinity compared to other compounds. The in vitro helminth bioassays and biochemical analysis suggest Persicaria strigosa a possible anthelmintic agent. However, isolation and characterization of bioactive compound(s) may promise new drug candidates for helminth infections.


Asunto(s)
Antihelmínticos , Helmintos/efectos de los fármacos , Extractos Vegetales , Polygonaceae , Animales , Antihelmínticos/farmacología , Antioxidantes/farmacología , Simulación del Acoplamiento Molecular , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Polygonaceae/química
17.
Chem Biodivers ; 18(9): e2100310, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34231306

RESUMEN

Propolis is a bee product that has been used in medicine since ancient times. Although its anti-inflammatory, antioxidant, antimicrobial, antitumor, and immunomodulatory activities have been investigated, its anti-parasitic properties remain poorly explored, especially regarding helminths. This review surveys the results obtained with propolis around the world against human parasites. Regarding protozoa, studies carried out with the protozoa Trypanosoma spp. and Leishmania spp. have demonstrated promising results in vitro and in vivo. However, there are fewer studies for Plasmodium spp., the etiological agent of malaria and less so for helminths, particularly for Fasciola spp. and Schistosoma spp. Despite the favorable in vitro results with propolis, helminth assays need to be further investigated. However, propolis has shown itself to be an excellent natural product for parasitology, thus opening new paths and approaches in its activity against protozoa and helminths.


Asunto(s)
Antiparasitarios/farmacología , Fenoles/farmacología , Extractos Vegetales/farmacología , Própolis/química , Animales , Antiparasitarios/química , Antiparasitarios/aislamiento & purificación , Brasil , Helmintos/efectos de los fármacos , Leishmania/efectos de los fármacos , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Fenoles/química , Fenoles/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Plasmodium/efectos de los fármacos , Trypanosoma/efectos de los fármacos
18.
Biomed Res Int ; 2021: 6682418, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34327236

RESUMEN

BACKGROUND: Soil-transmitted helminths (STHs) and Schistosoma mansoni are the main causes of morbidity among schoolchildren in the tropics. A school-based deworming program was launched to control and eliminate the infection in endemic countries including Ethiopia. Although periodic deworming is conducted in endemic areas, the prevalence of the infection is high in the country. In addition, periodic evaluation of the efficacy of the anthelminthic drug is limited. OBJECTIVE: This study is aimed at checking the efficacy of mebendazole and praziquantel with the respective STHs and Schistosoma mansoni parasites. METHODS: A longitudinal study was conducted from February to March 2018 among 422 schoolchildren. Stool samples were collected at baseline and at 2 and 4 weeks posttreatment and were processed using the Kato-Katz technique. Schoolchildren positive for STHs were treated with mebendazole and those positive for Schistosoma mansoni with praziquantel. After two weeks, a second round of stool was collected and examined, and then, single-dose redosing was given to each positive child. Lastly, the third stool sample was collected two weeks after the initiation of the redosing and checked for STHs and S. mansoni parasites. A close follow-up of students who were treated was done. All the data were entered and analyzed using SPSS version 20 for analysis. Descriptive statistics was used to compute the cure rate and egg reduction rate of mebendazole and praziquantel. RESULTS: Among 422 participants, the prevalence of STHs, hookworm, Ascaris lumbricoides, and S. mansoni was 44.7%, 35.1%, 21.1%, and 13.9%, respectively. The cure rate of mebendazole against A. lumbricoides increased from 60% in the single dose to 100% in redosing after two weeks. The cure rate of mebendazole against hookworm also increased from 32.4% in the single dose to 91.0% in the redosing. The cure rate of praziquantel against S. mansoni-infected children was 91.5% in the first round and 100% in the redosing phase. There was a 98.6-100% egg reduction rate in the redosing regimen of both drugs. CONCLUSION: The cure and egg reduction rates of single-dose mebendazole in the treatment of hookworm and A. lumbricoides are lower at week two than at redosing, while cure and egg reduction rates of single-dose praziquantel are satisfactory to treat S. mansoni. Therefore, single-dose praziquantel to S. mansoni and redosing of single-dose mebendazole to A. lumbricoides and hookworm infections can be used for treatment purposes.


Asunto(s)
Helmintos/fisiología , Mebendazol/uso terapéutico , Praziquantel/uso terapéutico , Schistosoma mansoni/fisiología , Esquistosomiasis mansoni/tratamiento farmacológico , Instituciones Académicas , Suelo/parasitología , Estudiantes , Adolescente , Animales , Niño , Etiopía , Femenino , Geografía , Helmintiasis/tratamiento farmacológico , Helmintiasis/parasitología , Helmintos/efectos de los fármacos , Humanos , Masculino , Mebendazol/farmacología , Óvulo/citología , Praziquantel/farmacología , Schistosoma mansoni/efectos de los fármacos , Esquistosomiasis mansoni/parasitología , Resultado del Tratamiento
19.
Trends Parasitol ; 37(9): 780-789, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34092518

RESUMEN

Most anthelmintics were discovered through in vivo screens using animal models of infection. Developing in vitro assays for parasitic worms presents several challenges. The lack of in vitro life cycle culture protocols requires harvesting worms from vertebrate hosts or vectors, limiting assay throughput. Once worms are removed from the host environment, established anthelmintics often show no obvious phenotype - raising concerns about the predictive value of many in vitro assays. However, with recent progress in understanding how anthelmintics subvert host-parasite interactions, and breakthroughs in high-content imaging and machine learning, in vitro assays have the potential to discern subtle cryptic parasite phenotypes. These may prove better endpoints than conventional in vitro viability assays.


Asunto(s)
Antihelmínticos , Evaluación Preclínica de Medicamentos , Animales , Antihelmínticos/farmacología , Helmintiasis/tratamiento farmacológico , Helmintos/efectos de los fármacos , Interacciones Huésped-Parásitos
20.
Am J Trop Med Hyg ; 104(6): 2251-2263, 2021 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-33844645

RESUMEN

According to the Kenya National School-Based Deworming program launched in 2012 and implemented for the first 5 years (2012-2017), the prevalence of soil-transmitted helminths (STH) and schistosomiasis substantially reduced over the mentioned period among the surveyed schools. However, this reduction is heterogeneous. In this study, we aimed to determine the factors associated with the 5-year school-level infection prevalence and relative reduction (RR) in prevalence in Kenya following the implementation of the program. Multiple variables related to treatment, water, sanitation, and hygiene (WASH) and environmental factors were assembled and included in mixed-effects linear regression models to identify key determinants of the school location STH and schistosomiasis prevalence and RR. Reduced prevalence of Ascaris lumbricoides was associated with low (< 1%) baseline prevalence, seven rounds of treatment, high (50-75%) self-reported coverage of household handwashing facility equipped with water and soap, high (20-25°C) land surface temperature, and community population density of 5-10 people per 100 m2. Reduced hookworm prevalence was associated with low (< 1%) baseline prevalence and the presence of a school feeding program. Reduced Trichuris trichiura prevalence was associated with low (< 1%) baseline prevalence. Reduced Schistosoma mansoni prevalence was associated with low (< 1%) baseline prevalence, three treatment rounds, and high (> 75%) reported coverage of a household improved water source. Reduced Schistosoma haematobium was associated with high aridity index. Analysis indicated that a combination of factors, including the number of treatment rounds, multiple related program interventions, community- and school-level WASH, and several environmental factors had a major influence on the school-level infection transmission and reduction.


Asunto(s)
Implementación de Plan de Salud/métodos , Helmintiasis/epidemiología , Higiene , Programas Nacionales de Salud/normas , Saneamiento , Esquistosomiasis/epidemiología , Suelo/parasitología , Agua , Animales , Estudios Transversales , Heces/parasitología , Implementación de Plan de Salud/normas , Implementación de Plan de Salud/estadística & datos numéricos , Helmintiasis/prevención & control , Helmintiasis/transmisión , Helmintos/clasificación , Helmintos/efectos de los fármacos , Humanos , Kenia/epidemiología , Modelos Estadísticos , Programas Nacionales de Salud/estadística & datos numéricos , Prevalencia , Análisis de Regresión , Esquistosomiasis/prevención & control , Esquistosomiasis/transmisión , Instituciones Académicas/estadística & datos numéricos
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