Active clinical trials for "Onchocerciasis"

This is an exploratory case control study with the aim to compare the Onchocerca volvulus virome between persons with onchocerciasis-associated epilepsy (OAE) and persons with onchocerciasis but without epilepsy. The main question we want to address is: Is there a virus contained in the O. volulus worm that may have a pathogenic role in causing OAE. In Maridi County, South Sudan, 20 persons with OAE with onchocerciasis nodules, and 20 age- and village-matched controls without OAE will be enrolled in a nodulectomy study.The adult O. volvulus worms will be extracted from the nodules and a viral metagenomic study of the worms. The O. volvulus virome of persons with and without OAE will be compared.

The DOLF Ocular Changes after Ivermectin study will investigate the kinetics of O. volvulus microfilaria (Mf) in the eye following treatment with ivermectin. The primary objective is to determine the proportion of participants with complete Mf clearance from the eye at 3 and 6 months following treatment with ivermectin (IVM).

Onchocerciasis is a neglected tropical disease associated with epilepsy, particularly in areas of high Onchocerciasis volvulus transmission. Onchocerciasis-associated epilepsy is characterised by seizures that start between the ages of five to 18 years. The tropical disease can be controlled through community-directed treatment with ivermectin (CDTi). Mahenge, in Tanzania, had a high prevalence of onchocerciasis and epilepsy despite more than 20 years of annual CDTi. Hence, the Tanzanian Neglected Tropical Diseases Control Programme has switched from annual to bi-annually CDTi since 2019. After this switch, the CDTi coverage increased and was sustained in both ivermectin rounds in 2021, and the number of new epilepsy cases decreased. The latter were persons who did not take ivermectin the year they had the first seizures. Hence, all ivermectin-eligible children at risk of onchocerciasis should take ivermectin at least annually. Overall, increasing the frequency and coverage of the CDTi programme should be considered in onchocerciasis-endemic areas with a high prevalence of epilepsy.

For the first time using a prospective design, a study confirms the results of previous retrospective studies, which found that strengthening onchocerciasis elimination efforts decreases the incidence of epilepsy, including nodding syndrome. Therefore, this study confirms the solid epidemiological link between onchocerciasis and epilepsy. This study also shows that a community-based "Slash and Clear" vector control method can effectively decrease blackfly biting rates and potentially decrease onchocerciasis transmission. Moreover, this study shows that epilepsy is a major cause of death in onchocerciasis endemic areas with high ongoing transmission.

Approximately 4,000 people will participate per year. The study population will include females and males over 5 years of age who live in filariasis and onchocerciasis endemic areas. Subject selection will not be based on health status. Two sites will be studied, and each study will last for 4 years. Participants will be studied only once in cross-sectional surveys. Some subjects may be included in more than one annual population survey, but this is not a longitudinal study. Investigators will compare annual and semiannual mass drug administration (MDA) for lymphatic filariasis and onchocerciasis, and investigators will compare the impact of these MDA schedules on soil transmitted helminth infections. MDA will be administered by others (Ivorian Ministry of Health). The investigators will test the hypothesis that semiannual mass drug administration (MDA) is superior to annual MDA for elimination of lymphatic filariasis, onchocerciasis and for control of soil transmitted helminth (STH) infections. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of lymphatic filariasis (LF) in these populations. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of onchocerciasis in these populations. Study the impact of annual vs. semiannual MDA on soil transmitted helminth (STH) infection in these populations.

Approximately 3,500 people will participate per year. The study population will include females and males over 5 years of age who live in filariasis endemic areas. The study will be performed in Indonesia in B. timori and W. bancrofti endemic areas over a period of 4 years. Participants will be studied only once in cross-sectional surveys. Some subjects may be included in more than one annual population survey, but this is not a longitudinal study. Purpose of the study is to evaluate different mass drug administration (MDA) regimens for lymphatic filariasis and also to study the impact of MDA on soil transmitted helminth infections (STH). MDA will administered by others (e.g., Ministry of Health). Results of this study may enhance efforts to control and eliminate these important neglected tropical diseases. The investigators will test the hypothesis that accelerated mass drug administration will be superior to annual MDA for elimination of lymphatic filariasis and for control of soil transmitted helminth infections (STH): Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of lymphatic filariasis (LF). Study the impact of annual vs. semiannual MDA on soil transmitted helminth (STH) infection in these populations.

Approximately 5,200 people will participate per year. The study population will include females and males over 5 years of age who live in filariasis and onchocerciasis endemic areas. Subject selection will not be based on health status. Two sites will be studied, and each study will last for 4 years. Participants will be studied only once in cross-sectional surveys. Some subjects may be included in more than one annual population survey, but this is not a longitudinal study. Investigators will compare annual and semiannual mass drug administration (MDA) for lymphatic filariasis and onchocerciasis, and investigators will compare the impact of these MDA schedules on soil transmitted helminth infections. MDA will be administered by others (Liberian Ministry of Health or Liberian Institute of Biomedical Research). The investigators will test the hypothesis that semiannual mass drug administration (MDA) is superior to annual MDA for elimination of lymphatic filariasis, onchocerciasis and for control of soil transmitted helminth (STH) infections. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of lymphatic filariasis (LF) in these populations. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of onchocerciasis in these populations. Study the impact of annual vs. semiannual MDA on soil transmitted helminth (STH) infection in these populations. Continuation Activities (2019/2020): Additional one-time cross-sectional surveys will be completed in the Harper site in Maryland district in 2019 and in Lofa in 2020 to measure the long-term impact of MDA on W. bancrofti, O. volvulus, and on STH infection parameters following these cumulative 7-9 rounds of MDA since the baseline survey taken in 2013. Since the last DOLF surveys (3rd follow-ups) in these sites in 2016 & 2017, respectively, there have been a total of 3 annual rounds of MDA in both areas. These additional surveys will recruit 2,500 participants in the Maryland area villages and 3,200 in the Lofa area villages.

Lymphatic filariasis is a neglected tropical disease earmarked for elimination as a public health problem by the year 2020. Since the year 2000, the Global Program for the Elimination of LF has together with endemic countries undertaken preventive chemotherapy in endemic districts to entire at risk populations. In Ghana, treatment of LF is based on the drugs Ivermectin and Albendazole. Remarkable achievements have been made towards the control and elimination of LF in Ghana. However, there remain programmatic and implementation challenges that need to be addressed in order to ensure that the gains made over the last 15 years are sustained. Among these challenges is the persistent transmission of LF in some districts despite more than 10 years of MDA. Furthermore, LF cases have been identified in communities from eight districts, previously considered as non-endemic. The extent of endemicity in these new districts is unknown. In order to achieve the 2020 elimination targets, it is crucial to determine the distribution and infection prevalence of LF in these districts. Evaluating these districts for LF endemicity will help the implementation of appropriate strategies towards achieving the 2020 target. This protocol describes the surveys to be undertaken in Ghana in 3 of these districts. The current standard mapping methodologies of LF have the potential to miss LF endemic villages, due to the focal nature of LF. As such, in order to enhance the chances to detect endemic communities, this survey will use a combination of the WHO EPI cluster survey and current LF mapping protocols. 15 communities will be selected in each district, with 100 survey participants per community. Survey participants will be screened for LF infection using immunological and parasitological methods. Study participants will also be tested for onchocerciasis infection using immunological and parasitological methods in districts where LF and oncho are co-endemic. The information from this survey will be combined with the data on the LF vectors and their infection status in the survey areas and relevant data available at the Ghana Health Service to: determine whether LF intervention strategies are indicated in these three districts, design, as indicated, appropriate intervention strategies to achieve LF elimination in these three districts by 2020 inform, if indicated, co-implementation of control, monitoring and evaluation for LF and onchocerciasis in the two onchocerciasis endemic districts extract lessons learnt for the design and implementation of surveys in the other districts currently considered non-endemic but where LF cases have been reported. New rapid diagnostic tests have been developed to assess infection Lf and onchocerciasis infection prevalence at the time of the decision to stop MDA and for surveillance for new infections once MDA has been stopped. These include Rapid Diagnostic Tests (RDT) for antibodies against the W. bancrofti antigen WB123 and the O. volvulus antigen Ov16. These tests still require large scale field validation. Provided additional funding becomes available, this survey will be used to obtain field validation data.

Background: Childhood epilepsy disorders are particular frequent in the area around Mahenge, southern Tanzania and recent studies have described a novel type of epilepsy with repetitive head nodding episodes and often progressive cognitive dysfunction. Despite the disease affecting thousands in Tanzania, Uganda and South Sudan, etiology and pathogenesis of the disorder termed Nodding Syndrome (NS) is still obscure as the phenotype remains imprecisely described. Epidemiological associations with Onchocerca volvulus and Mansonella spp. were noted at different African sites and remain robust even though no evidence for the presence of O. volvulus in CSF or any previous contact with the CSF was found. Hypothesis: With regard to the complex host immune reaction to O. volvulus, the investigators hypothesize that the immune response against filariae might contribute to NS and epilepsy. The investigators further assume that specific genetic traits might play a role in the pathogenesis of NS. Aims In the present study the investigators aim to examine if and how O. volvulus and/or Mansonella spp. contribute to the pathology of NS/epilepsy and therefore intend to analyze the filarial infection and the host immune response in affected children. To identify inherited traits predisposing for epilepsy, NS or specific immune responses, a genetic workup that includes whole-exome sequencing (WES) is performed. The clinical and EEG characteristics are further defined. Cognitive impairment of people with epilepsy and NS is assessed using the Wechsler Nonverbal Scale of Ability (WNV). Study design: A cross-sectional observational (groups I-III) and a case-control (groups I-V) study recruiting in total 250 patients and controls (I: people with NS, n=50; II: people with epilepsy (PWE) and onchocerciasis, n=50; III: PWE without onchocerciasis, n=50; IV: controls with onchocerciasis but otherwise healthy, n= 50; healthy controls without evidence for onchocerciasis, n= 50) is performed to describe the clinical characteristics in children with NS/epilepsy and to evaluate differences in infection and immune response between groups, respectively. The WNV should be validated in 500 healthy controls to obtain reference data in rural Africa. Summary: In summary, the study aims to elucidate clinical characteristics and the pathogenesis of NS/epilepsy in children of southern Tanzania and role of parasitic infection as a cause for NS/epilepsy.