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1.
Epilepsia Open ; 9(2): 467-474, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38243880

RESUMEN

Epilepsy imposes a substantial burden on the Democratic Republic of Congo (DRC). These challenges encompass the lack of comprehensive disease surveillance, an unresolved understanding of its pathophysiology, economic barriers limiting access to essential care, the absence of epilepsy surgical capabilities, and deeply ingrained societal stigmas. Notably, the national prevalence of epilepsy remains undetermined, with research primarily concentrating on infectious factors like Onchocerca volvulus, leaving other potential causes underexplored. Most patients lack insurance, incurring out-of-pocket expenses that often lead them to opt for traditional medicine rather than clinical care. Social stigma, perpetuated by common misconceptions, intensifies the social isolation experienced by individuals living with epilepsy. Additionally, surgical interventions are unavailable, and the accessibility of anti-seizure medications and healthcare infrastructure remains inadequate. Effectively tackling these interrelated challenges requires a multifaceted approach, including conducting research into region-specific factors contributing to epilepsy, increasing healthcare funding, subsidizing the costs of treatment, deploying mobile tools for extensive screening, launching awareness campaigns to dispel myths and reduce stigma, and promoting collaborations between traditional healers and medical practitioners to enhance local understanding and epilepsy management. Despite the difficulties, significant progress can be achieved through sustained and compassionate efforts to understand and eliminate the barriers faced by epilepsy patients in the region. This review outlines essential steps for alleviating the epilepsy burden in the DRC. PLAIN LANGUAGE SUMMARY: There are not enough resources to treat epilepsy in the DRC. PWEs struggle with stigma and the lack of money. Many of them still use traditional medicine for treatment and hold wrong beliefs about epilepsy. That is why there is a need for more resources to make the lives of PWEs better in the DRC.


Asunto(s)
Epilepsia , Onchocerca volvulus , Oncocercosis , Animales , Humanos , República Democrática del Congo/epidemiología , Oncocercosis/complicaciones , Oncocercosis/epidemiología , Onchocerca volvulus/fisiología , Epilepsia/tratamiento farmacológico , Factores de Riesgo
2.
BMC Public Health ; 23(1): 1784, 2023 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-37710219

RESUMEN

BACKGROUND: Neglected tropical diseases (NTDs) are a major public health burden which mainly affects poor populations living in tropical environments and hard-to-reach areas. The study sought to examine coverage of preventive efforts, and case surveillance for NTDs in hard-to-reach communities in Ghana. METHODS: The study investigated treatment efforts for lymphatic filariasis (LF), and onchocerciasis and schistosomiasis/soil transmitted helminths (SCH/STH) at household level, in difficult-to-access communities in Ghana. A total of 621 households were sampled from 6 communities in the Western, Oti and Greater Accra regions. RESULTS: Over 95% of the households surveyed were covered under mass drug administration (MDA) campaigns for lymphatic filariasis (LF) and onchocerciasis. More than 80% of households had received at least two visits by community drug distributors under the MDA campaigns in the last two years preceding the study. In addition, over 90% of households in the LF and onchocerciasis endemic communities had at least one member using anthelminthic medications under the MDA campaigns in the 12 months preceding the study. However, households where no member had taken anthelminthic medications in 12 months preceding the study were over 6 times likely to have someone in the household with LF. CONCLUSIONS: This study determined that SCH/STH, LF and onchocerciasis are of serious public health concern in some communities in Ghana. There is an urgent need for holistic practical disease control plan involving both financial and community support to ensure total control of NTDs in difficult-to-access communities is achieved.


Asunto(s)
Filariasis Linfática , Oncocercosis , Humanos , Ghana/epidemiología , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Oncocercosis/prevención & control , Administración Masiva de Medicamentos , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/prevención & control , Suelo
3.
Am J Trop Med Hyg ; 108(4): 801-806, 2023 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-36848896

RESUMEN

Neglected tropical diseases (NTDs) receive relatively little research and development but have a tremendous impact on lifespan and livelihood. Here, we use existing data on the need for drugs, their efficacy, and their treatment percentages to estimate the impacts of various regimens on the global burden of several NTDs: schistosomiasis, onchocerciasis, lymphatic filariasis, and three soil-transmitted helminths (STHs) over time. For an interactive visualization of our models' results, see https://www.global-health-impact.org/. In 2015, our NTD models estimate that treatment averted 2,778,131.78 disability-adjusted life years (DALYs). Together, treatments targeting STHs together averted 51.05% of the DALYs averted from all NTD treatments, whereas schistosomiasis, lymphatic filariasis, and onchocerciasis medicines averted 40.21%, 7.56%, and 1.18%, respectively. Our models highlight the importance of focusing not just on the burden of these diseases but also on their alleviation in the effort to expand access to treatment.


Asunto(s)
Filariasis Linfática , Oncocercosis , Esquistosomiasis , Medicina Tropical , Humanos , Salud Global , Enfermedades Desatendidas , Suelo , Accesibilidad a los Servicios de Salud
4.
PLoS Negl Trop Dis ; 16(4): e0010341, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35468134

RESUMEN

Hyperreactive onchocerciasis (HO) is characterized by a severe skin inflammation with elevated Th17-Th2 combined responses. We previously demonstrated the anthelminthic activity of Aframomum melegueta (AM), Xylopia aethiopica (XA) and Khaya senegalensis (KS) used by traditional healers to treat helminthiasis in the endemic area of Togo. However, their effect on severe onchocerciasis is poorly investigated. The present study aimed to investigate the anti-Th17 and anti-Th2 effects of hydro-ethanolic extracts of AM, XA and KS during HO. Onchocerca volvulus-infected individuals were recruited in the Central region of Togo in 2018. Isolated peripheral blood mononuclear cells (PBMCs) from both generalized onchocerciasis (GEO) and HO forms were activated with anti-CD3 and anti-CD28 monoclonal antibodies in the presence or absence of the hydro-ethanolic extracts of AM, XA and KS as well as their delipidated, deproteinized and deglycosylated fractions. After 72 hours, cytokines were assayed from cell culture supernatants. Then, flow cytometry was used to investigate the effects of the extracts on cell activation, proliferation, intracellular cytokines and T cells transcription factors. The production of both Th17 and Th2 cytokines IL-17A and IL-5 were significantly inhibited upon T-cell receptor (TCR) activation in the presence of the hydro-ethanolic extracts of AM, XA and KS in HO individuals' PBMCs in vitro. AM and XA inhibited CD4+RORC2+IL-17A+ and CD4+GATA3+IL-4+ cell populations induction. This inhibition was not Th1 nor Treg-dependent since both IFN-γ and IL-10 were also inhibited by the extracts. AM and XA did not interfere with T cell activation and proliferation for their inhibitory pathways. Lipid and protein compounds from AM and XA were associated with the inhibition of IL-17A. This study showed that in addition to their anthelminthic effects, hydro-ethanolic extracts of Aframomum melegueta, Xylopia aethiopica and Khaya senegalensis could downregulate both Th17 and Th2 responses and prevent the severe skin disorder observed.


Asunto(s)
Meliaceae , Oncocercosis , Xylopia , Zingiberaceae , Citocinas/metabolismo , Humanos , Interleucina-17/metabolismo , Leucocitos Mononucleares , Extractos Vegetales/farmacología , Células TH1 , Células Th17
5.
Parasit Vectors ; 14(1): 305, 2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34099047

RESUMEN

BACKGROUND: Drugs currently used for controlling onchocerciasis and lymphatic filariasis (LF) are mainly microfilaricidal, with minimal or no effect on the adult worms. For efficient management of these diseases, it is necessary to search for new drugs with macrofilaricidal activities that can be used singly or in combination with existing ones. Daniellia oliveri and Psorospermum febrifugum are two plants commonly used in the local management of these infections in Bambui, a township in the North West Region of Cameroon, but there is currently no documented scientific evidence to support their claimed anthelmintic efficacy and safety. The aim of this study was to provide evidence in support of the search for means to eliminate these diseases by screening extracts and chromatographic fractions isolated from these plants for efficacy against the parasitic roundworms Onchocerca ochengi and Brugia pahangi. METHODS: The viability of O. ochengi adult worms was assessed using the MTT/formazan assay. Fully confluent monkey kidney epithelial cells (LLC-MK2) served as the feeder layer for the O. ochengi microfilariae (mfs) assays. Viability of the mfs was assessed by microscopic examination for mean motility scoring (relative to the negative control) every 24 h post addition of an extract. The Worminator system was used to test the effects of the extracts on adult B. pahangi motility, and mean motility units were determined for each worm. Cytotoxicity of the active extracts on N27 cells was assessed using the MTS assay. RESULTS: Extracts from D. oliveri and P. febrifugum were effective against the adult roundworms O. ochengi and B. pahangi. Interestingly, extracts showing macrofilaricidal activities against O. ochengi also showed activity against O. ochengi mfs. The hexane stem bark extract of D. oliveri (DOBHEX) was more selective for adult O. ochengi than for mfs, with a half maximal and 100% inhibitory concentration (IC50 and IC100, respectively) against adult O. ochengi of 13.9 and 31.3 µg/ml, respectively. The in vitro cytotoxicity of all active extracts on N27 cells showed selective toxicity for parasites (selectivity index > 1). Bioassay-guided fractionation of the extracts yielded fractions with activity against adult B. pahangi, thus confirming the presence of bioactive principles in the plant extracts. CONCLUSIONS: Our study supports the use of D. oliveri and P. febrifugum in the traditional treatment of onchocerciasis and LF. The further purification of active extracts from these plants could yield lead compounds for filarial drug discovery and development.


Asunto(s)
Clusiaceae/química , Fabaceae/química , Filaricidas/farmacología , Onchocerca/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Camerún , Línea Celular , Haplorrinos , Humanos , Onchocerca/crecimiento & desarrollo , Oncocercosis/tratamiento farmacológico , Oncocercosis/parasitología , Corteza de la Planta/química
6.
PLoS Pathog ; 17(6): e1009601, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34077488

RESUMEN

Onchocerciasis (river blindness), caused by the filarial worm Onchocerca volvulus, is a neglected tropical disease mostly affecting sub-Saharan Africa and is responsible for >1.3 million years lived with disability. Current control relies almost entirely on ivermectin, which suppresses symptoms caused by the first-stage larvae (microfilariae) but does not kill the long-lived adults. Here, we evaluated emodepside, a semi-synthetic cyclooctadepsipeptide registered for deworming applications in companion animals, for activity against adult filariae (i.e., as a macrofilaricide). We demonstrate the equivalence of emodepside activity on SLO-1 potassium channels in Onchocerca volvulus and Onchocerca ochengi, its sister species from cattle. Evaluation of emodepside in cattle as single or 7-day treatments at two doses (0.15 and 0.75 mg/kg) revealed rapid activity against microfilariae, prolonged suppression of female worm fecundity, and macrofilaricidal effects by 18 months post treatment. The drug was well tolerated, causing only transiently increased blood glucose. Female adult worms were mostly paralyzed; however, some retained metabolic activity even in the multiple high-dose group. These data support ongoing clinical development of emodepside to treat river blindness.


Asunto(s)
Enfermedades de los Bovinos/tratamiento farmacológico , Depsipéptidos/uso terapéutico , Filaricidas/uso terapéutico , Canales de Potasio de Gran Conductancia Activados por el Calcio/efectos de los fármacos , Oncocercosis/tratamiento farmacológico , Oncocercosis/veterinaria , Animales , Bovinos , Onchocerca/efectos de los fármacos
7.
PLoS Negl Trop Dis ; 15(2): e0009206, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33621233

RESUMEN

BACKGROUND: A high prevalence of epilepsy has been observed in several onchocerciasis-endemic villages in the Sanaga River basin, Cameroon. Recent studies suggest that ivermectin, a drug that is distributed annually with the aim of eliminating onchocerciasis, may have a protective effect against acquiring onchocerciasis-associated epilepsy (OAE). This study, therefore, provides an in-depth understanding of both the complex therapeutic landscape for epilepsy as well as the experiences related to the 'community-directed treatment with ivermectin' (CDTI) campaign in order to identify a more trenchant path forward in the fight against epilepsy. METHODOLOGY/PRINCIPAL FINDINGS: Based on a mixed methods study combining a qualitative strand with a quantitative survey, we found that epilepsy was perceived to have had an epidemic emergence in the past and was still considered an important health issue in the study area. Socio-economic status, availability and accessibility of drugs and practitioners, as well as perceived aetiology shaped therapeutic itineraries for epilepsy, which included frequenting (in)formal biomedical health care providers, indigenous and/or faith healing practitioners. Ivermectin uptake for onchocerciasis was generally well known and well regarded. The CDTI faced structural and logistical bottlenecks undermining equal access and optimal adherence to the drug. CONCLUSIONS/SIGNIFICANCE: Locally accessible, uninterrupted, sustainable and comprehensive health-service delivery is essential to help alleviate the epilepsy burden on afflicted households. Addressing structural challenges of CDTI and communicating the potential link with epilepsy to local populations at risk could optimize the uptake of this potentially significant tool in OAE prevention.


Asunto(s)
Epilepsia/complicaciones , Oncocercosis/complicaciones , Oncocercosis/tratamiento farmacológico , Adulto , Camerún/epidemiología , Estudios Transversales , Epilepsia/epidemiología , Femenino , Humanos , Ivermectina/uso terapéutico , Masculino , Persona de Mediana Edad , Oncocercosis/epidemiología , Prevalencia , Factores Socioeconómicos , Encuestas y Cuestionarios
8.
Seizure ; 81: 151-156, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32810838

RESUMEN

INTRODUCTION: Epilepsy is a major public health concern in sub-Saharan Africa, particularly in resource-limited rural villages where persons with epilepsy (PWE) are often confronted with a wide treatment gap, frequent stigma and high cost of epilepsy care. We investigated stigma and economic cost related to epilepsy in the states of Maridi and Amadi in South Sudan, two onchocerciasis endemic areas with high epilepsy prevalence. METHODS: Between November 2019 and February 2020, community-based surveys were conducted in eight villages of Maridi and Amadi States. Consenting PWE were identified via a door-to-door approach, and perceived stigma was assessed using the validated Kilifi stigma scale. Additional data about household income, as well as epilepsy-related direct and indirect costs were collected. RESULTS: 239 PWE were recruited (95 from Maridi, 144 from Amadi). Stigma scores were higher in Maridi compared to Amadi (mean scores: 13.9 vs 6.5, p < 0.001). Mean weighted epilepsy costs per month in Maridi (38.4 USD) were double those observed in Amadi (17.6 USD). The main epilepsy-related expenditure was the purchase of anti-epileptic drugs (AED). Stigma scores correlated with epilepsy cost (Spearman-rho = 0.24, p < 0.001) and were positively associated with traditional medicine use (regression estimate = 1.9; p = 0.027). CONCLUSION: In rural South Sudan, PWE and their families often experienced stigma from the community. Higher perceived stigma was associated with traditional medicine use, which increased the overall cost of epilepsy management. Demystifying epilepsy and making AED more accessible would improve the quality of life of PWE and their families, and reduce the economic burden of epilepsy.


Asunto(s)
Epilepsia , Oncocercosis , Epilepsia/tratamiento farmacológico , Epilepsia/epidemiología , Humanos , Oncocercosis/complicaciones , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Calidad de Vida , Estigma Social , Sudán del Sur
9.
Am J Trop Med Hyg ; 103(3): 1135-1142, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32588807

RESUMEN

Wambabya-Rwamarongo onchocerciasis focus is one of the eight foci Uganda verified using the WHO verification guidelines. The approach for elimination was twice yearly treatment with ivermectin for every round, treating at least 90% of all the eligible population. This was in combination with vector elimination using Abate® (BASF SE, Limburgerhof, Germany) since elimination nationwide policy was launched. From 2008 to 2013, the program distributed ivermectin with a mean treatment coverage of the ultimate treatment goal (UTG) or eligible population of 91.2%, with a range of 85-96%. In 2009, vector elimination based on ground larviciding had a dramatic impact on the Simulium vectors, as the last fly was observed in October 2009. No more Simulium vectors were observed during a period of at least 7 years, including the 3-year posttreatment surveillance (PTS) until the focus was reclassified as eliminated in August 2017. During the PTS period, none of the 10,578 trapped crabs were found infested with the aquatic stages of the vector. The last infested crab was observed in March 2010, and for at least 7 years, no infested crabs were observed. Serological surveys showed that of 2,978 young children examined in 2013, only one was OV16 positive (0.0%; 95% CI: 0-0.21). In 2017, after the PTS period, all 3,079 young children examined were negative for OV16 (95% CI: 0-0.16). Therefore, entomological and serological results provided evidence that resulted in the reclassification of Wambabya-Rwamarongo focus from "transmission interrupted" to "transmission eliminated" with no possibility of recrudescence.


Asunto(s)
Antiparasitarios/uso terapéutico , Braquiuros/parasitología , Ivermectina/uso terapéutico , Oncocercosis/epidemiología , Simuliidae/parasitología , Temefós/uso terapéutico , Animales , Erradicación de la Enfermedad , Humanos , Oncocercosis/parasitología , Oncocercosis/transmisión , Uganda/epidemiología
10.
PLoS Negl Trop Dis ; 13(9): e0007710, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31490931

RESUMEN

BACKGROUND: Integrated disease management, disability and inclusion (DMDI) for NTDs is increasingly prioritised. There is limited evidence on the effectiveness of integrated DMDI from the perspective of affected individuals and how this varies by differing axes of inequality such as age, gender, and disability. We used narrative methods to consider how individuals' unique positions of power and privilege shaped their illness experience, to elucidate what practical and feasible steps could support integrated DMDI in Liberia and beyond. METHODS: We purposively selected 27 participants affected by the clinical manifestations of lymphatic filariasis, leprosy, Buruli Ulcer, and onchocerciasis from three counties in Liberia to take part in illness narrative interviews. Participants were selected to ensure maximum variation in age, gender and clinical manifestation. Narrative analysis was grounded within feminist intersectional theory. FINDINGS: For all participants, chronic illness, morbidity and disability associated with NTDs represented a key moment of 'biographical disruption' triggering the commencement of a restitution narrative. Complex health seeking pathways, aetiologies and medical syncretism meant that adoption of the 'sick role' was initially acceptable, but when the reality of permanency of condition was identified, a transition to periods of chaos and significant psycho-social difficulty occurred. An intersectional lens emphasises how biographical disruption is mediated by intersecting social processes. Gender, generation, and disability were all dominant axes of social inequity shaping experience. SIGNIFICANCE: This is one of the first studies to use narrative approaches to interrogate experience of chronic disabling conditions within LMICs and is the only study to apply such an analysis to NTDs. The emotive power of narrative should be utilised to influence the value base of policy makers to ensure that DMDI strategies respond holistically to the needs of the most marginalised, thus contributing to more equitable people-centred care.


Asunto(s)
Enfermedad Crónica/psicología , Enfermedades Desatendidas/psicología , Adaptación Psicológica , Adolescente , Adulto , Úlcera de Buruli/psicología , Personas con Discapacidad/psicología , Filariasis Linfática/psicología , Femenino , Humanos , Lepra/psicología , Liberia , Acontecimientos que Cambian la Vida , Masculino , Persona de Mediana Edad , Oncocercosis/psicología
11.
PLoS Negl Trop Dis ; 13(7): e0007556, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31260456

RESUMEN

BACKGROUND: Onchocerciasis currently afflicts an estimated 15 million people and is the second leading infectious cause of blindness world-wide. The development of a macrofilaricide to cure the disease has been hindered by the lack of appropriate small laboratory animal models. This study therefore, was aimed at developing and validating the Mongolian gerbil, as an Onchocerca ochengi (the closest in phylogeny to O. volvulus) adult male worm model. METHODOLOGY/PRINCIPAL FINDINGS: Mongolian gerbils (Meriones unguiculatus) were each implanted with 20 O. ochengi male worms (collected from infected cattle), in the peritoneum. Following drug or placebo treatments, the implanted worms were recovered from the animals and analyzed for burden, motility and viability. Worm recovery in control gerbils was on average 35%, with 89% of the worms being 100% motile. Treatment of the gerbils implanted with male worms with flubendazole (FBZ) resulted in a significant reduction (p = 0.0021) in worm burden (6.0% versus 27.8% in the control animals); all recovered worms from the treated group had 0% worm motility versus 91.1% motility in control animals. FBZ treatment had similar results even after four different experiments. Using this model, we tested a related drug, oxfendazole (OFZ), and found it to also significantly (p = 0.0097) affect worm motility (22.7% versus 95.0% in the control group). CONCLUSIONS/SIGNIFICANCE: We have developed and validated a novel gerbil O. ochengi adult male worm model for testing new macrofilaricidal drugs in vivo. It was also used to determine the efficacy of oxfendazole in vivo.


Asunto(s)
Modelos Animales de Enfermedad , Filaricidas/uso terapéutico , Gerbillinae/parasitología , Onchocerca/efectos de los fármacos , Oncocercosis/veterinaria , Animales , Bencimidazoles/uso terapéutico , Evaluación Preclínica de Medicamentos/métodos , Femenino , Masculino , Mebendazol/análogos & derivados , Mebendazol/uso terapéutico , Movimiento , Oncocercosis/parasitología
12.
Parasitol Res ; 117(9): 2697-2713, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30008135

RESUMEN

Onchocerciasis is a filarial vector borne disease which affects several million people mostly in Africa. The therapeutic approach of its control was based on a succession of drugs which always showed limits. The last one: ivermectin is not the least. It was shown to be only microfilaricidal and induced resistance to the human parasite Onchocerca volvulus. The approach using medicinal plants used in traditional medicine is a possible alternative method to cure onchocerciasis. Onchocerca ochengi and Onchocerca gutturosa are the parasite models used to assess anthelmintic activity of potentially anthelmintic plants. Numerous studies assessed the in vitro and/or in vivo anthelmintic activity of medicinal plants. Online electronic databases were consulted to gather publications on in vitro and in vivo studies of anti-Onchocerca activity of plants from 1990 to 2017. Globally, 13 plant families were investigated for anti-Onchocerca activity in 13 studies. The most active species were Anacardium occidentale, Euphorbia hirta and Acacia nilotica each with an LC50 value of 2.76, 6.25 and 1.2 µg/mL, respectively. Polycarpol, voacamine, voacangine, ellagic acid, gallic acid, gentisic acid, 3-O-acetyl aleuritolic acid and (-)-epigallocatechin 3-O-gallate were the isolated plant compounds with anti-Onchocerca activity. Most of the assessed extract/compounds showed a good safety after in vivo acute toxicity assays and/or in vitro cytotoxicity test. The exception was the ethanol extract of Trichilia emetica, which killed completely and drastically mice at a dose of 3000 mg/kg. Several plant groups of compounds were shown active against Onchocerca sp. such as tannins, alkaloids, triterpenoids and essential oils. Nevertheless, none of the active compounds was subjected to clinical trial, to assessment of its diffusibility through nodular wall or its capability to induce genetic resistance of Onchocerca sp.


Asunto(s)
Antihelmínticos/farmacología , Onchocerca volvulus/efectos de los fármacos , Oncocercosis/tratamiento farmacológico , Extractos Vegetales/farmacología , Plantas Medicinales/química , Acacia/química , África , Anacardium/química , Animales , Euphorbia/química , Humanos , Ivermectina/farmacología , Onchocerca volvulus/aislamiento & purificación , Oncocercosis/parasitología , Taninos/análisis
13.
BMJ Open ; 8(6): e020113, 2018 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-29961005

RESUMEN

INTRODUCTION: Worldwide, millions of individuals are affected by neglected tropical diseases (NTDs). They are frequently the poorest and most marginalised members of society. Their living conditions, among other things, make them susceptible to such diseases. Historically, several large-scale treatment programmes providing mass drug administrations (MDAs) were carried out per single disease but over the last decade there has been an increasing trend towards co-implementation of MDA activities given the resources used for such programmes are often the same. The COUNTDOWN multicountry studies focus on scaled-up implementation of integrated control strategies against four diseases: lymphatic filariasis, onchocerciasis, schistosomiasis and soil-transmitted helminthiasis. The objective of the COUNTDOWN economic study is to assess the multicountry implementation of control interventions in terms of equity, impact and efficiency. METHODS: The health economic study uses different analytical methods to assess the relationship between NTDs and poverty and the cost-effectiveness of different large-scale intervention options. Regression analysis will be used to study the determinants of NTD occurrence, the impact of NTDs on poverty, factors that hinder access to MDAs and the effect of NTDs on quality-of-life of those affected, including disability. Cost-effectiveness analyses of various integration methods will be performed using health economic modelling to estimate the cost and programme impact of different integration options. Here, cost-effectiveness ratios will be calculated, including multivariate sensitivity analyses, using Bayesian analysis. ETHICS AND DISSEMINATION: Ethics approval has been received both at the Liverpool School of Tropical Medicine and in all participating countries. Results of the various substudies will be presented for publication in peer-reviewed journals. STUDY DATES: 1 July 2016 to 30 June-October 2019.


Asunto(s)
Análisis Costo-Beneficio , Prestación Integrada de Atención de Salud/economía , Administración Masiva de Medicamentos/economía , Enfermedades Desatendidas/economía , Enfermedades Desatendidas/prevención & control , Teorema de Bayes , Camerún , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/economía , Ghana , Gastos en Salud , Helmintiasis/tratamiento farmacológico , Helmintiasis/economía , Humanos , Liberia , Análisis Multivariante , Enfermedades Desatendidas/tratamiento farmacológico , Oncocercosis/tratamiento farmacológico , Oncocercosis/economía , Pobreza , Proyectos de Investigación , Esquistosomiasis/tratamiento farmacológico , Esquistosomiasis/economía , Clima Tropical
14.
PLoS Negl Trop Dis ; 12(6): e0006565, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29897908

RESUMEN

BACKGROUND: Ivermectin is the only drug currently recommended for the treatment of onchocerciasis, the second leading infectious cause of blindness in the world. This drug kills only the first stage larvae-microfilariae (mf) of Onchocerca volvulus and is to be used cautiously in areas where Loa loa is prevalent because of severe adverse events observed with coinfected patients. METHODOLOGY/PRINCIPAL FINDINGS: This study investigated the anti-filarial activities of two Cameroonian medicinal plants, Lantana camara and Tamarindus indica locally used to treat onchocerciasis. Twelve (12) extracts were prepared and tested in vitro on the bovine model parasite, O. ochengi as well as L. loa mf. Both mf and adult male worm viabilities were assessed by motility scoring, while adult female worm viability was determined biochemically by standard MTT/formazan colorimetry. Cytotoxicity and acute toxicity were determined respectively, in monkey kidney epithelial cells and in BALB/c mice. Pure compounds were isolated by LC/MS using a bio-assay guided strategy. All the extracts showed 100% activity at 500 µg/mL against O. ochengi adult worms and mf. The highest activity against O. ochengi was observed with the hexane extract of L. camara leaves (LCLhex), with IC50 of 35.1 µg/mL for adult females and 3.8 µg/mL for the mf. Interestingly, this extract was more active against O. ochengi mf than L. loa mf. Further studies on the extracts led to the isolation of lantadene A from the methylene chloride extract of L. camara leaves, with IC50s of 7.85 µg/mL for adult males, 10.38 µg/mL for adult females, 10.84 µg/mL for O. ochengi mf and 20.13 µg/mL for L. loa mf. CONCLUSIONS/SIGNIFICANCE: We report for the first time the anti-onchocercal activities of these locally consumed medicinal plants and lantadene A, a potential lead for further development as an onchocerciasis cure.


Asunto(s)
Lantana/química , Loiasis/tratamiento farmacológico , Ácido Oleanólico/análogos & derivados , Oncocercosis/tratamiento farmacológico , Extractos Vegetales/farmacología , Tamarindus/química , Animales , Femenino , Filaricidas/uso terapéutico , Humanos , Concentración 50 Inhibidora , Loa/aislamiento & purificación , Loiasis/parasitología , Masculino , Ratones Endogámicos BALB C , Microfilarias , Ácido Oleanólico/farmacología , Onchocerca/aislamiento & purificación , Oncocercosis/parasitología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Plantas Medicinales
15.
BMC Complement Altern Med ; 17(1): 404, 2017 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28806951

RESUMEN

BACKGROUND: Onchocerciasis is one of the tropical neglected diseases (NTDs) caused by the nematode Onchocerca volvulus. Control strategies currently in use rely on mass administration of ivermectin, which has marked activity against microfilariae. Furthermore, the development of resistance to ivermectin was observed. Since vaccine and safe macrofilaricidal treatment against onchocerciasis are still lacking, there is an urgent need to discover novel drugs. This study was undertaken to investigate the anthelmintic activity of Lophira lanceolata on the cattle parasite Onchocerca ochengi and the anthelmintic drug resistant strains of the free living nematode Caenorhabditis elegans and to determine the phytochemical profiles of the extracts and fractions of the plants. METHODS: Plant was extracted in ethanol or methanol-methylene chloride. O. ochengi, C. elegans wild-type and C. elegans drug resistant strains were cultured in RPMI-1640 and NGM-agar respectively. Drugs diluted in dimethylsulphoxide/RPMI or M9-Buffer were added in assays and monitored at 48 h and 72 h. Worm viability was determined by using the MTT/formazan colorimetric method. Polyphenol, tannin and flavonoid contents were determined by dosage of gallic acid and rutin. Acute oral toxicity was evaluated using Swiss albino mice. RESULTS: Ethanolic and methanolic-methylene chloride extracts killed O. ochengi with LC50 values of 9.76, 8.05, 6.39 µg/mL and 9.45, 7.95, 6.39 µg/mL respectively for leaves, trunk bark and root bark after 72 h. The lowest concentrations required to kill 50% of the wild-type of C. elegans were 1200 and 1890 µg/mL with ethanolic crude extract, 1000 and 2030 µg/mL with MeOH-CH2Cl2 for root bark and trunk bark of L. lanceolata, respectively after 72 h. Leave extracts of L. lanceolata are lethal to albendazole and ivermectin resistant strains of C. elegans after 72 h. Methanol/methylene chloride extracted more metabolites. Additionally, extracts could be considered relatively safe. CONCLUSION: Ethanolic and methanolic-methylene chloride crude extracts and fractions of L. lanceolata showed in vitro anthelmintic activity. The extracts and fractions contained polyphenols, tannins, flavonoids and saponins. The mechanism of action of this plant could be different from that of albendazole and ivermectin. These results confirm the use of L. lanceolata by traditional healers for the treatment of worm infections.


Asunto(s)
Antihelmínticos/farmacología , Caenorhabditis elegans , Infecciones por Nematodos/parasitología , Ochnaceae/química , Onchocerca , Extractos Vegetales/farmacología , Albendazol/farmacología , Animales , Bovinos , Resistencia a Medicamentos , Flavonoides/análisis , Flavonoides/farmacología , Ivermectina/farmacología , Ratones , Infecciones por Nematodos/veterinaria , Oncocercosis/parasitología , Oncocercosis/veterinaria , Fitoterapia , Corteza de la Planta , Extractos Vegetales/química , Raíces de Plantas , Tallos de la Planta , Polifenoles/análisis , Polifenoles/farmacología , Saponinas/análisis , Saponinas/farmacología , Taninos/análisis , Taninos/farmacología
16.
BMC Infect Dis ; 16(1): 404, 2016 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-27515037

RESUMEN

BACKGROUND: Onchocerciasis, caused by the parasitic nematode, Onchocerca volvulus afflicts some 37 million people worldwide, and is the second leading infectious cause of blindness globally. The only currently recommended drug for treatment of the disease, ivermectin, is only microfilaricidal and has serious adverse effects in individuals co-infected with high loads of Loa loa microfilariae (mf), prompting the search for new and better drugs. Onchocerciasis drug discovery studies have so far been based on in vivo models using Onchocerca species which are not the closest to O. volvulus, and which may therefore, not adequately mimic the natural infection in humans. Therefore, this study was carried out to develop a better drug screening model for onchocerciasis, based on the use of cow-derived O. ochengi, the closest known relative of O. volvulus. METHODS: Mf of O. ochengi were injected subcutaneously at the nape of Syrian hamsters (Mesocricetus auratus) and BALB/c mice. The skin, and especially the earlobes of the animals were examined for mf 15-31 days after infection. For selected model validation, the hamsters were treated with ivermectin at 150 or 600 µg/kg body weight and examined 30 days after infection for mf. For L. loa studies in hamsters, isolated mf were injected intraperitoneally and animal organs were examined on day 26 for mf. RESULTS: The Syrian hamsters were found to be the more permissive to O. ochengi mf as fully viable mf were recovered from them on day 30, compared to BALB/c mice where such mf were recovered on day 15, but not 30. However, both animals were not permissive to L. loa mf even by day 15. Interestingly, more than 50 % of the total O. ochengi mf recovered were from the earlobes. The number of mf injected was directly proportional to the number recovered. Ivermectin at both concentrations tested completely eliminated the O. ochengi mf from the hamsters. CONCLUSION: This study reveals the Syrian hamster as an appropriate small animal model for screening of novel compounds against O. ochengi, the closest known relative of O. volvulus.


Asunto(s)
Ivermectina/uso terapéutico , Onchocerca/patogenicidad , Oncocercosis/etiología , Animales , Cricetinae , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Femenino , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Loa/aislamiento & purificación , Loa/patogenicidad , Masculino , Ratones , Ratones Endogámicos BALB C , Onchocerca/aislamiento & purificación , Oncocercosis/tratamiento farmacológico
17.
Int Health ; 8 Suppl 1: i28-33, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26940307

RESUMEN

Programmes to control onchocerciasis have been ongoing for over 40 years. What was once a devastating blinding and disabling disease, particularly in West Africa, has largely been eliminated at least as a public health problem. Efforts continue to eliminate the transmission of the disease. However, as the elimination agenda has developed so have efforts to control/eliminate other neglected tropical diseases (NTDs). The African Programme for Onchocerciasis Control will close at the end of 2015. There has been considerable discussion as to what should replace it and the World Health Organization Africa Region has been consulting widely during the first part of 2015 and has established a new project framework that will be presented to a wider group of stakeholders to mobilise support with the aim of the coordination of NTD activities in the region. This will be called the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN). This will put the countries in the driving seat but offer technical advice, capacity building and financial support, where needed, to enable countries to implement their NTD Master Plans, and also to implement recommendations of the Regional Programme Review Group. An NTD forum will be held periodically to consult with stakeholders.


Asunto(s)
Enfermedades Desatendidas/prevención & control , Medicina Tropical , Organización Mundial de la Salud/organización & administración , África , África Occidental , Conducta Cooperativa , Filariasis Linfática/prevención & control , Humanos , Oncocercosis/prevención & control , Salud Pública
20.
Arch Dis Child ; 101(7): 640-7, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26921274

RESUMEN

Chagas disease, leishmaniasis, onchocerciasis and lymphatic filariasis are all vectorborne neglected tropical diseases (NTDs) that are responsible for significant disease burden in impoverished children and adults worldwide. As vectorborne parasitic diseases, they can all be targeted for elimination through vector control strategies. Examples of successful vector control programmes for these diseases over the past two decades have included the Southern Cone Initiative against Chagas disease, the Kala-azar Control Scheme against leishmaniasis, the Onchocerciasis Control Programme and the lymphatic filariasis control programme in The Gambia. A common vector control component in all of these programmes is the use of adulticides including dichlorodiphenyltrichloroethane and newer synthetic pyrethroid insecticides against the insect vectors of disease. Household spraying has been used against Chagas disease and leishmaniasis, and insecticide-treated bed nets have helped prevent leishmaniasis and lymphatic filariasis. Recent trends in vector control focus on collaborations between programmes and sectors to achieve integrated vector management that addresses the holistic vector control needs of a community rather than approaching it on a disease-by-disease basis, with the goals of increased efficacy, sustainability and cost-effectiveness. As evidence of vector resistance to currently used insecticide regimens emerges, research to develop new and improved insecticides and novel control strategies will be critical in reducing disease burden. In the quest to eliminate these vectorborne NTDs, efforts need to be made to continue existing control programmes, further implement integrated vector control strategies and stimulate research into new insecticides and control methods.


Asunto(s)
Salud Infantil , Insectos Vectores , Enfermedades Desatendidas/prevención & control , Enfermedades Parasitarias/prevención & control , Animales , Enfermedad de Chagas/prevención & control , Enfermedad de Chagas/transmisión , Filariasis/prevención & control , Filariasis/transmisión , Salud Global , Humanos , Control de Insectos/métodos , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Oncocercosis/prevención & control , Oncocercosis/transmisión , Enfermedades Parasitarias/transmisión
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