The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
María-gloria Basáñez - One of the best experts on this subject based on the ideXlab platform.
-
Moxidectin: an oral treatment for human Onchocerciasis
Expert review of anti-infective therapy, 2020Co-Authors: Philip Milton, Martin Walker, Jonathan I D Hamley, María-gloria BasáñezAbstract:Moxidectin is a milbemycin endectocide recently approved for the treatment of human Onchocerciasis. Onchocerciasis, earmarked for elimination of transmission, is a filarial infection endemic in Afr...
-
Economic evaluations of Onchocerciasis interventions: a systematic review and research needs
Tropical Medicine & International Health, 2019Co-Authors: Hugo C.turner, Sébastien Pion, Martin Walker, Deborah A. Mcfarland, Donald A. P. Bundy, María-gloria BasáñezAbstract:OBJECTIVE : To provide a systematic review of economic evaluations that has been conducted for Onchocerciasis interventions, to summarise current key knowledge and to identify research gaps. METHOD : A systematic review of the literature was conducted on the 8th of August 2018 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. No date or language stipulations were applied to the searches. RESULTS : We identified 14 primary studies reporting the results of economic evaluations of Onchocerciasis interventions, seven of which were cost-effectiveness analyses. The studies identified used a variety of different approaches to estimate the costs of the investigated interventions/programmes. Originally, the studies only quantified the benefits associated with preventing blindness. Gradually, methods improved and also captured Onchocerciasis-associated skin disease. Studies found that eliminating Onchocerciasis would generate billions in economic benefits. The majority of the cost-effectiveness analyses evaluated annual mass drug administration (MDA). The estimated cost per disability-adjusted life year (DALY) averted of annual MDA varies between US$3 and US$30 (cost year variable). CONCLUSIONS : The cost benefit and cost effectiveness of Onchocerciasis interventions have consistently been found to be very favourable. This finding provides strong evidential support for the ongoing efforts to eliminate Onchocerciasis from endemic areas. Although these results are very promising, there are several important research gaps that need to be addressed as we move towards the 2020 milestones and beyond.
-
Report of the first international workshop on Onchocerciasis-associated epilepsy.
Infectious Diseases of Poverty, 2018Co-Authors: Robert Colebunders, Michel Boussinesq, Sarah O'neill, An Hotterbeekx, Joseph Kamgno, Patrick Suykerbuyk, Michel Mandro, Alfred Njamnshi, Adrian Hopkins, María-gloria BasáñezAbstract:Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that Onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where Onchocerciasis is still endemic. MAIN TEXT: On October 12-14th 2017, the first international workshop on Onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries. Recent research findings strongly suggest that O. volvulus is an important contributor to epilepsy, particularly in meso- and hyperendemic areas for Onchocerciasis. Infection with O. volvulus is associated with a spectrum of epileptic seizures, mainly generalised tonic-clonic seizures but also atonic neck seizures (nodding), and stunted growth. OAE is characterised by an onset of seizures between the ages of 3-18 years. Multidisciplinary working groups discussed topics such as how to 1) strengthen the evidence for an association between Onchocerciasis and epilepsy, 2) determine the burden of disease caused by OAE, 3) prevent OAE, 4) improve the treatment/care for persons with OAE and affected families, 5) identify the pathophysiological mechanism of OAE, and 6) deal with misconceptions, stigma, discrimination and gender violence associated with OAE. An OAE Alliance was created to increase awareness about OAE and its public health importance, stimulate research and disseminate research findings, and create partnerships between OAE researchers, communities, advocacy groups, ministries of health, non-governmental organisations, the pharmaceutical industry and funding organizations. CONCLUSIONS: Although the exact pathophysiological mechanism underlying OAE remains unknown, there is increasing evidence that by controlling and eliminating Onchocerciasis, OAE will also disappear. Therefore, OAE constitutes an additional argument for strengthening Onchocerciasis elimination efforts. Given the high numbers of people with epilepsy in O. volvulus-endemic regions, more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.
-
report of the first international workshop on Onchocerciasis associated epilepsy
Infectious Diseases of Poverty, 2018Co-Authors: Robert Colebunders, Michel Boussinesq, Alfred K. Njamnshi, An Hotterbeekx, Joseph Kamgno, Patrick Suykerbuyk, Michel Mandro, Adrian Hopkins, Sarah Oneill, María-gloria BasáñezAbstract:Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that Onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where Onchocerciasis is still endemic. On October 12–14th 2017, the first international workshop on Onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries. Recent research findings strongly suggest that O. volvulus is an important contributor to epilepsy, particularly in meso- and hyperendemic areas for Onchocerciasis. Infection with O. volvulus is associated with a spectrum of epileptic seizures, mainly generalised tonic-clonic seizures but also atonic neck seizures (nodding), and stunted growth. OAE is characterised by an onset of seizures between the ages of 3–18 years. Multidisciplinary working groups discussed topics such as how to 1) strengthen the evidence for an association between Onchocerciasis and epilepsy, 2) determine the burden of disease caused by OAE, 3) prevent OAE, 4) improve the treatment/care for persons with OAE and affected families, 5) identify the pathophysiological mechanism of OAE, and 6) deal with misconceptions, stigma, discrimination and gender violence associated with OAE. An OAE Alliance was created to increase awareness about OAE and its public health importance, stimulate research and disseminate research findings, and create partnerships between OAE researchers, communities, advocacy groups, ministries of health, non-governmental organisations, the pharmaceutical industry and funding organizations. Although the exact pathophysiological mechanism underlying OAE remains unknown, there is increasing evidence that by controlling and eliminating Onchocerciasis, OAE will also disappear. Therefore, OAE constitutes an additional argument for strengthening Onchocerciasis elimination efforts. Given the high numbers of people with epilepsy in O. volvulus-endemic regions, more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.
-
Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns
Parasites & Vectors, 2018Co-Authors: Jorge Cano, Samuel Wanji, María-gloria Basáñez, Simon O’hanlon, Afework Tekle, Honorat Zouré, Maria P. Rebollo, Rachel L. PullanAbstract:Background Onchocerciasis and lymphatic filariasis (LF) are major filarial infections targeted for elimination in most endemic sub-Saharan Africa (SSA) countries by 2020/2025. The current control strategies are built upon community-directed mass administration of ivermectin (CDTI) for Onchocerciasis, and ivermectin plus albendazole for LF, with evidence pointing towards the potential for novel drug regimens. When distributing microfilaricides however, considerable care is needed to minimise the risk of severe adverse events (SAEs) in areas that are co-endemic for Onchocerciasis or LF and loiasis. This work aims to combine previously published predictive risk maps for Onchocerciasis, LF and loiasis to (i) explore the scale of spatial heterogeneity in co-distributions, (ii) delineate target populations for different treatment strategies, and (iii) quantify populations at risk of SAEs across the continent. Methods Geographical co-endemicity of filarial infections prior to the implementation of large-scale mass treatment interventions was analysed by combining a contemporary LF endemicity map with predictive prevalence maps of Onchocerciasis and loiasis. Potential treatment strategies were geographically delineated according to the level of co-endemicity and estimated transmission intensity. Results In total, an estimated 251 million people live in areas of LF and/or Onchocerciasis transmission in SSA, based on 2015 population estimates. Of these, 96 million live in areas co-endemic for both LF and Onchocerciasis, providing opportunities for integrated control programmes, and 83 million live in LF-monoendemic areas potentially targetable for the novel ivermectin-diethylcarbamazine-albendazole (IDA) triple therapy. Only 4% of the at-risk population live in areas co-endemic with high loiasis transmission, representing up to 1.2 million individuals at high risk of experiencing SAEs if treated with ivermectin. In these areas, alternative treatment strategies should be explored, including biannual albendazole monotherapy for LF (1.4 million individuals) and ‘test-and-treat’ strategies (8.7 million individuals) for Onchocerciasis. Conclusions These maps are intended to initiate discussion around the potential for tailored treatment strategies, and highlight populations at risk of SAEs. Further work is required to test and refine strategies in programmatic settings, providing the empirical evidence needed to guide efforts towards the 2020/2025 goals and beyond.
Samuel Wanji - One of the best experts on this subject based on the ideXlab platform.
-
Projected number of people with Onchocerciasis-Loiasis co-infection in Africa, 1995 to 2025
Clinical Infectious Diseases, 2020Co-Authors: Natalie V.s. Vinkeles Melchers, Sébastien Pion, Samuel Wanji, Jan H. F. Remme, Michel Boussinesq, Afework Tekle, Honorat Zouré, Luc E. Coffeng, Belen Pedrique, Wilma A. StolkAbstract:BACKGROUND: Onchocerciasis elimination through mass drug administration (MDA) is hampered by co-endemicity of Loa loa in Africa, as people with high L. loa microfilariae (mf) density can develop serious adverse events (SAEs) after ivermectin treatment. We assessed the geographical overlap of Onchocerciasis and loiasis prevalence and estimated the number of co-infected individuals at risk of post-ivermectin SAEs in West and Central Africa from 1995 to 2025. METHODS: Focussing on regions with suspected loiasis transmission in 14 African countries, we overlaid pre-control maps of loiasis and Onchocerciasis prevalence to calculate pre-control prevalence of co-infection by 5x5 km² pixel, distinguishing different categories of L. loa mf intensity. Using statistical and mathematical models, we predicted the prevalence of both infections and co-infection for 2015 and 2025, accounting for the impact of MDA with ivermectin. RESULTS: The number of people infected with Onchocerciasis was predicted to decline from almost 19 million in 1995 to 4 million in 2025. Of these, 137,000 people were estimated to also have L. loa hypermicrofilaraemia (≥20,000 L. loa mf/mL) in 1995, declining to 31,000 in 2025. In 2025, 92.8% of co-infected cases with loiasis hypermicrofilaraemia are predicted to live in hypoendemic areas currently not targeted for MDA. CONCLUSIONS: Loiasis co-infection is a major concern for Onchocerciasis elimination in Africa. We predict that under current strategies, at least 31,000 co-infected people will still require treatment for Onchocerciasis in 2025 while being at risk of SAEs, justifying continued efforts in research and development for safer drugs and control strategies.
-
implementation of test and treat with doxycycline and temephos ground larviciding as alternative strategies for accelerating Onchocerciasis elimination in an area of loiasis co endemicity the countdown consortium multi disciplinary study protocol
Parasites & Vectors, 2019Co-Authors: Samuel Wanji, Abdel Jelil Njouendou, Raphael Awah Abong, Theobald Mue Nji, Louise Hamill, Laura Dean, Kim Ozano, Elisabeth Dibando Obie, Andrew Amuam, Relindis EkanyaAbstract:Onchocerciasis is a priority neglected tropical disease targeted for elimination by 2025. The standard strategy to combat Onchocerciasis is annual Community-Directed Treatment with ivermectin (CDTi). Yet, high prevalence rates and transmission persist following > 12 rounds in South-West Cameroon. Challenges include programme coverage, adherence to, and acceptability of ivermectin in an area of Loa loa co-endemicity. Loiasis patients harbouring heavy infections are at risk of potentially fatal serious adverse events following CDTi. Alternative strategies are therefore needed to achieve Onchocerciasis elimination where CDTi effectiveness is suboptimal. We designed an implementation study to evaluate integrating World Health Organisation-endorsed alternative strategies for the elimination of Onchocerciasis, namely test-and-treat with the macrofilaricide, doxycycline (TTd), and ground larviciding for suppression of blackfly vectors with the organophosphate temephos. A community-based controlled before-after intervention study will be conducted among > 2000 participants in 20 intervention (Meme River Basin) and 10 control (Indian River Basin) communities. The primary outcome measure is O. volvulus prevalence at follow-up 18-months post-treatment. The study involves four inter-disciplinary components: parasitology, entomology, applied social sciences and health economics. Onchocerciasis skin infection will be diagnosed by skin biopsy and Loa loa infection will be diagnosed by parasitological examination of finger-prick blood samples. A simultaneous clinical skin disease assessment will be made. Eligible skin-snip-positive individuals will be offered directly-observed treatment for 5 weeks with 100 mg/day doxycycline. Transmission assessments of Onchocerciasis in the communities will be collected post-human landing catch of the local biting blackfly vector prior to ground larviciding with temephos every week (0.3 l/m3) until biting rate falls below 5/person/day. Qualitative research, including in-depth interviews and focus-group discussions will be used to assess acceptability and feasibility of the implemented alternative strategies among intervention recipients and providers. Health economics will assess the cost-effectiveness of the implemented interventions. Using a multidisciplinary approach, we aim to assess the effectiveness of TTd, alone or in combination with ground larviciding, following a single intervention round and scrutinise the acceptability and feasibility of implementing at scale in similar hotspots of Onchocerciasis infection, to accelerate Onchocerciasis elimination.
-
Ecological properties and history of community-directed treatment with ivermectin (CDTi) of communities/villages screened for the presence of lymphatic filariasis in Cameroon.
2019Co-Authors: Samuel Wanji, Mathias E Esum, Abdel Jelil Njouendou, Amuam Andrew Mbeng, Patrick Chounna W. Ndongmo, Raphael Awah Abong, Jerome Fru, Fanny F. Fombad, Gordon Takop Nchanji, Glory NgongehAbstract:Health districts that were hyper- or mesoendemic for Onchocerciasis received CDTi while districts hypoendemic for Onchocerciasis received no CDTi.
-
Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns
Parasites & Vectors, 2018Co-Authors: Jorge Cano, Samuel Wanji, María-gloria Basáñez, Simon O’hanlon, Afework Tekle, Honorat Zouré, Maria P. Rebollo, Rachel L. PullanAbstract:Background Onchocerciasis and lymphatic filariasis (LF) are major filarial infections targeted for elimination in most endemic sub-Saharan Africa (SSA) countries by 2020/2025. The current control strategies are built upon community-directed mass administration of ivermectin (CDTI) for Onchocerciasis, and ivermectin plus albendazole for LF, with evidence pointing towards the potential for novel drug regimens. When distributing microfilaricides however, considerable care is needed to minimise the risk of severe adverse events (SAEs) in areas that are co-endemic for Onchocerciasis or LF and loiasis. This work aims to combine previously published predictive risk maps for Onchocerciasis, LF and loiasis to (i) explore the scale of spatial heterogeneity in co-distributions, (ii) delineate target populations for different treatment strategies, and (iii) quantify populations at risk of SAEs across the continent. Methods Geographical co-endemicity of filarial infections prior to the implementation of large-scale mass treatment interventions was analysed by combining a contemporary LF endemicity map with predictive prevalence maps of Onchocerciasis and loiasis. Potential treatment strategies were geographically delineated according to the level of co-endemicity and estimated transmission intensity. Results In total, an estimated 251 million people live in areas of LF and/or Onchocerciasis transmission in SSA, based on 2015 population estimates. Of these, 96 million live in areas co-endemic for both LF and Onchocerciasis, providing opportunities for integrated control programmes, and 83 million live in LF-monoendemic areas potentially targetable for the novel ivermectin-diethylcarbamazine-albendazole (IDA) triple therapy. Only 4% of the at-risk population live in areas co-endemic with high loiasis transmission, representing up to 1.2 million individuals at high risk of experiencing SAEs if treated with ivermectin. In these areas, alternative treatment strategies should be explored, including biannual albendazole monotherapy for LF (1.4 million individuals) and ‘test-and-treat’ strategies (8.7 million individuals) for Onchocerciasis. Conclusions These maps are intended to initiate discussion around the potential for tailored treatment strategies, and highlight populations at risk of SAEs. Further work is required to test and refine strategies in programmatic settings, providing the empirical evidence needed to guide efforts towards the 2020/2025 goals and beyond.
-
Additional file 1: of Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns
2018Co-Authors: Jorge Cano, Samuel Wanji, María-gloria Basáñez, Simon O’hanlon, Afework Tekle, Honorat Zouré, Maria Rebollo, Rachel PullanAbstract:Pan-African and country-specific (i.e. Cameroon and Democratic Republic of Congo) maps for lymphatic filariasis (LF); LF and Onchocerciasis co-endemicity; LF, Onchocerciasis and loiasis co-endemicity, and population estimates aggregated by African region. Text S1. Pan-African maps of lymphatic filariasis (LF). Figure S1. Pan-African map of LF endemicity at the level of implementation units (IU). Figure S2. Pan-African map of co-endemic areas for LF and Onchocerciasis. Figure S3. Map of loiasis, LF and Onchocerciasis co-endemicity in eastern Cameroon. Figure S4. Map of loiasis, LF and Onchocerciasis co-endemicity in Oriental province, DRC. Table S1. Estimates of population living in endemic areas for lymphatic filariasis (LF) and/or Onchocerciasis (oncho). Table S2. Population estimates for co-endemic areas of lymphatic filariasis, Onchocerciasis and high prevalence of loiasis. (DOCX 2183 kb
E. Tukesiga - One of the best experts on this subject based on the ideXlab platform.
-
Onchocerciasis associated epilepsy with head nodding seizures nodding syndrome a case series of 15 patients from western uganda 1994
American Journal of Tropical Medicine and Hygiene, 2018Co-Authors: Christoph Kaiser, E. Tukesiga, George Asaba, Tom Rubaale, Walter KippAbstract:Nodding syndrome (NS) is an encephalopathy characterized by the core symptom of epileptic head nodding seizures, affecting children at the age between 3 and 18 years in distinct areas of tropical Africa. A consistent correlation with Onchocerciasis was found, but so far, the causation of NS has not been fully clarified. With a systematic analysis of features of a cohort of epilepsy patients examined in the Itwara Onchocerciasis focus of western Uganda in 1994, we provide evidence that NS actually occurred in this area at this time, and we demonstrate a correlation between prevalence of NS and that of Onchocerciasis in different villages. Following the elimination of Onchocerciasis by community-directed treatment with ivermectin and ground larviciding, our data provide a baseline to examine the question whether NS will disappear once its putative cause has been removed.
-
the interruption of onchocerca volvulus and wuchereria bancrofti transmission by integrated chemotherapy in the obongi focus north western uganda
PLOS ONE, 2017Co-Authors: Lakwo Thomson Luroni, P. Habomugisha, E. Tukesiga, Matwale Gabriel, Edridah Tukahebwa, Ambrose Winston Onapa, Benjamin Tinkitina, Michael Nyaraga, Anna Mary Auma, Edson ByamukamaAbstract:Intervention Few studies have documented the interruption of Onchocerciasis and Lymphatic Filariasis (LF) by integrated chemotherapy in Uganda. The study describes the interruption of transmission of the two diseases co-endemic in Obongi focus, north western Uganda. Base line data for Onchocerciasis and LF were collected in 1994 and 2006, respectively. Annual mass drug administration for Onchocerciasis (Ivermectin) and Lymphatic Filariasis (Ivermectin + albendazole) was conducted for 20 and 6 years, respectively. Thereafter, assessments by skin snip, larval searches in rivers and human landing catches were performed. Children <10 years were screened for IgG4 antibodies using Ov16 ELISA technique in 2013. LF Pre-TAS and TAS1 were conducted in sentinel sites. ITN coverage and utilization for the implementation unit was also reported. Intervention coverage Onchocerciasis treatment coverage was 65% was achieved in the six treatment rounds. Household ownership of ITN’s and utilization was 96% and 72.4%., respectively. Impact Parasitological examinations conducted for Onchocerciasis among 807 adults and children, revealed a reduction in mf prevalence from 58% in 1994 to 0% in 2012. Entomological monitoring conducted at the two sites had no single Simulium damnosum fly caught. Serological analysis using Ov16 ELISA for Onchocerciasis revealed that out of the 3,308 children <10 years old screened in 2013, only 3/3308 (0.091%) positive cases were detected. All Ov16 positive children were negative when tested for patent infection by skin snip PCR. A reduction in LF microfilaria prevalence from 2.5% (n = 13/522) in 2006 to 0.0% (n = 602) in 2014 was observed. LF TAS1 conducted in 2015 among 1,532 children 6–7 years, all were negative for antigens of W. bancrofti. Conclusion The results concluded that interruption of Onchocerciasis and LF has been achieved.
-
The interruption of Onchocerca volvulus and Wuchereria bancrofti transmission by integrated chemotherapy in the Obongi focus, North Western Uganda
2017Co-Authors: Lakwo Thomson Luroni, P. Habomugisha, E. Tukesiga, Matwale Gabriel, Edridah Tukahebwa, Ambrose Winston Onapa, Benjamin Tinkitina, Michael Nyaraga, Anna Mary Auma, Edson ByamukamaAbstract:InterventionFew studies have documented the interruption of Onchocerciasis and Lymphatic Filariasis (LF) by integrated chemotherapy in Uganda. The study describes the interruption of transmission of the two diseases co-endemic in Obongi focus, north western Uganda. Base line data for Onchocerciasis and LF were collected in 1994 and 2006, respectively. Annual mass drug administration for Onchocerciasis (Ivermectin) and Lymphatic Filariasis (Ivermectin + albendazole) was conducted for 20 and 6 years, respectively. Thereafter, assessments by skin snip, larval searches in rivers and human landing catches were performed. Children
-
Transmission of Onchocerciasis in Wadelai focus of northwestern Uganda has been interrupted and the disease eliminated
Journal of Parasitology Research, 2012Co-Authors: Moses N Katabarwa, T. L. Lakwo, P. Habomugisha, Stella Agunyo, Dickson Unoba, Edson Byamukama, F. Walsh, David Were Oguttu, Thomas R. Unnasch, E. TukesigaAbstract:Wadelai, an isolated focus for Onchocerciasis in northwest Uganda, was selected for piloting an Onchocerciasis elimination strategy that was ultimately the precursor for countrywide Onchocerciasis elimination policy. The Wadelai focus strategy was to increase ivermectin treatments from annual to semiannual frequency and expand geographic area in order to include communities with nodule rate of less than 20%. These communities had not been covered by the previous policy that sought to control Onchocerciasis only as a public health problem. From 2006 to 2010, Wadelai program successfully attained ultimate treatment goal (UTG), treatment coverage of ≥90%, despite expanding from 19 to 34 communities and from 5,600 annual treatments to over 29,000 semiannual treatments. Evaluations in 2009 showed no microfilaria in skin snips of over 500 persons examined, and only 1 of 3011 children was IgG4 antibody positive to the OV16 recombinant antigen. No Simulium vectors were found, and their disappearance could have sped up interruption of transmission. Although twice-per-year treatment had an unclear role in interruption of transmission, the experience demonstrated that twice-per-year treatment is feasible in the Ugandan setting. The monitoring data support the conclusion that Onchocerciasis has been eliminated from the Wadelai focus of Uganda.
Afework Tekle - One of the best experts on this subject based on the ideXlab platform.
-
Projected number of people with Onchocerciasis-Loiasis co-infection in Africa, 1995 to 2025
Clinical Infectious Diseases, 2020Co-Authors: Natalie V.s. Vinkeles Melchers, Sébastien Pion, Samuel Wanji, Jan H. F. Remme, Michel Boussinesq, Afework Tekle, Honorat Zouré, Luc E. Coffeng, Belen Pedrique, Wilma A. StolkAbstract:BACKGROUND: Onchocerciasis elimination through mass drug administration (MDA) is hampered by co-endemicity of Loa loa in Africa, as people with high L. loa microfilariae (mf) density can develop serious adverse events (SAEs) after ivermectin treatment. We assessed the geographical overlap of Onchocerciasis and loiasis prevalence and estimated the number of co-infected individuals at risk of post-ivermectin SAEs in West and Central Africa from 1995 to 2025. METHODS: Focussing on regions with suspected loiasis transmission in 14 African countries, we overlaid pre-control maps of loiasis and Onchocerciasis prevalence to calculate pre-control prevalence of co-infection by 5x5 km² pixel, distinguishing different categories of L. loa mf intensity. Using statistical and mathematical models, we predicted the prevalence of both infections and co-infection for 2015 and 2025, accounting for the impact of MDA with ivermectin. RESULTS: The number of people infected with Onchocerciasis was predicted to decline from almost 19 million in 1995 to 4 million in 2025. Of these, 137,000 people were estimated to also have L. loa hypermicrofilaraemia (≥20,000 L. loa mf/mL) in 1995, declining to 31,000 in 2025. In 2025, 92.8% of co-infected cases with loiasis hypermicrofilaraemia are predicted to live in hypoendemic areas currently not targeted for MDA. CONCLUSIONS: Loiasis co-infection is a major concern for Onchocerciasis elimination in Africa. We predict that under current strategies, at least 31,000 co-infected people will still require treatment for Onchocerciasis in 2025 while being at risk of SAEs, justifying continued efforts in research and development for safer drugs and control strategies.
-
Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns
Parasites & Vectors, 2018Co-Authors: Jorge Cano, Samuel Wanji, María-gloria Basáñez, Simon O’hanlon, Afework Tekle, Honorat Zouré, Maria P. Rebollo, Rachel L. PullanAbstract:Background Onchocerciasis and lymphatic filariasis (LF) are major filarial infections targeted for elimination in most endemic sub-Saharan Africa (SSA) countries by 2020/2025. The current control strategies are built upon community-directed mass administration of ivermectin (CDTI) for Onchocerciasis, and ivermectin plus albendazole for LF, with evidence pointing towards the potential for novel drug regimens. When distributing microfilaricides however, considerable care is needed to minimise the risk of severe adverse events (SAEs) in areas that are co-endemic for Onchocerciasis or LF and loiasis. This work aims to combine previously published predictive risk maps for Onchocerciasis, LF and loiasis to (i) explore the scale of spatial heterogeneity in co-distributions, (ii) delineate target populations for different treatment strategies, and (iii) quantify populations at risk of SAEs across the continent. Methods Geographical co-endemicity of filarial infections prior to the implementation of large-scale mass treatment interventions was analysed by combining a contemporary LF endemicity map with predictive prevalence maps of Onchocerciasis and loiasis. Potential treatment strategies were geographically delineated according to the level of co-endemicity and estimated transmission intensity. Results In total, an estimated 251 million people live in areas of LF and/or Onchocerciasis transmission in SSA, based on 2015 population estimates. Of these, 96 million live in areas co-endemic for both LF and Onchocerciasis, providing opportunities for integrated control programmes, and 83 million live in LF-monoendemic areas potentially targetable for the novel ivermectin-diethylcarbamazine-albendazole (IDA) triple therapy. Only 4% of the at-risk population live in areas co-endemic with high loiasis transmission, representing up to 1.2 million individuals at high risk of experiencing SAEs if treated with ivermectin. In these areas, alternative treatment strategies should be explored, including biannual albendazole monotherapy for LF (1.4 million individuals) and ‘test-and-treat’ strategies (8.7 million individuals) for Onchocerciasis. Conclusions These maps are intended to initiate discussion around the potential for tailored treatment strategies, and highlight populations at risk of SAEs. Further work is required to test and refine strategies in programmatic settings, providing the empirical evidence needed to guide efforts towards the 2020/2025 goals and beyond.
-
Additional file 1: of Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns
2018Co-Authors: Jorge Cano, Samuel Wanji, María-gloria Basáñez, Simon O’hanlon, Afework Tekle, Honorat Zouré, Maria Rebollo, Rachel PullanAbstract:Pan-African and country-specific (i.e. Cameroon and Democratic Republic of Congo) maps for lymphatic filariasis (LF); LF and Onchocerciasis co-endemicity; LF, Onchocerciasis and loiasis co-endemicity, and population estimates aggregated by African region. Text S1. Pan-African maps of lymphatic filariasis (LF). Figure S1. Pan-African map of LF endemicity at the level of implementation units (IU). Figure S2. Pan-African map of co-endemic areas for LF and Onchocerciasis. Figure S3. Map of loiasis, LF and Onchocerciasis co-endemicity in eastern Cameroon. Figure S4. Map of loiasis, LF and Onchocerciasis co-endemicity in Oriental province, DRC. Table S1. Estimates of population living in endemic areas for lymphatic filariasis (LF) and/or Onchocerciasis (oncho). Table S2. Population estimates for co-endemic areas of lymphatic filariasis, Onchocerciasis and high prevalence of loiasis. (DOCX 2183 kb
-
The geographic distribution of Onchocerciasis in the 20 participating countries of the African Programme for Onchocerciasis Control: (1) priority areas for ivermectin treatment.
Parasites & vectors, 2014Co-Authors: Mounkaila Noma, Peter Enyong, Afework Tekle, Honorat G. M. Zouré, B. E. B. Nwoke, Jan H. F. RemmeAbstract:Background The African Programme for Onchocerciasis Control (APOC) was created to control Onchocerciasis as a public health problem in 20 African countries. Its main strategy is community directed treatment with ivermectin. In order to identify all high risk areas where ivermectin treatment was needed, APOC used Rapid Epidemiological Mapping of Onchocerciasis (REMO). REMO has now been virtually completed and we report the results in two articles. The present article reports the mapping of high risk areas where Onchocerciasis was a public health problem. The companion article reports the results of a geostatistical analysis of the REMO data to map endemicity levels and estimate the number infected.
Robert Colebunders - One of the best experts on this subject based on the ideXlab platform.
-
Meta-analysis of epilepsy prevalence in West Africa and its relationship with Onchocerciasis endemicity and control
Tropical Medicine & International Health, 2020Co-Authors: Joseph Nelson Siewe Fodjo, Jan Remme, Pierre-marie Preux, Robert ColebundersAbstract:Background: A high prevalence and incidence of epilepsy has been reported in Onchocerciasis-endemic regions in Central and East Africa. There is compelling epidemiological evidence suggesting that this high burden is caused by Onchocerciasis-associated epilepsy (OAE).We hypothesized that OAE had also occured inWest African Onchocerciasis foci. Methods: We searched PubMed, the African Journals Online platform and grey literature for population-based epilepsy studies inWest African countries. Epilepsy and Onchocerciasis prevalence data were extracted. The precontrol Onchocerciasis endemicity in the study siteswas estimated from historical data of Onchocerciasis control programmes. The prevalence of epilepsy in different sites was analysed, taking into account Onchocerciasis endemicity and the duration of control. Results: The pooled prevalence of epilepsy in theWest African study sites was 13.14 per 1000 (95% confidence interval 11.28–15.00). Higher pre-control endemicity and a shorter duration of Onchocerciasis control were both associated with increased epilepsy prevalence (p
-
Burden of Onchocerciasis-associated epilepsy: first estimates and research priorities
Infectious Diseases of Poverty, 2018Co-Authors: Natalie V.s. Vinkeles Melchers, Robert Colebunders, Luc E. Coffeng, Julia Irani, Sarah Mollenkopf, Michael Edlinger, Trésor Zola, Joseph N. Siewe, Sake J. De Vlas, Andrea S. WinklerAbstract:Background Since the 1990s, evidence has accumulated of an increased prevalence of epilepsy in Onchocerciasis-endemic areas in Africa as compared to Onchocerciasis-free areas. Although the causal relationship between Onchocerciasis and epilepsy has yet to be proven, there is likely an association. Here we discuss the need for disease burden estimates of Onchocerciasis-associated epilepsy (OAE), provide them, detail how such estimates should be refined, and discuss the socioeconomic impact of OAE, including a cost-estimate for anti-epileptic drugs. Main body Providing OAE burden estimates may aid prevention of epilepsy in Onchocerciasis- endemic areas by inciting and informing collaboration between Onchocerciasis control programmes and mental health services. Epilepsy not only massively impacts the health of those affected, but it also carries a high socioeconomic burden for the households and communities involved. We used previously published geospatial estimates of Onchocerciasis in Africa and a separately published logistic regression model quantifying the association between Onchocerciasis and epilepsy to estimate the number of OAE cases. We then applied disability weights for epilepsy to quantify the burden in terms of years of life lived with disability (YLD) and estimate the cost of treatment. We estimate that in 2015 roughly 117 000 people were affected by OAE across Onchocerciasis-endemic areas previously under the African Programme for Onchocerciases control (APOC) mandate where OAE has ever been reported or suspected, and another 264 000 persons in Onchocerciasis-endemic areas where OAE has never been investigated before. The total number of YLDs due to OAE was 39 300 and 88 700 in these areas respectively, based on a weighted mean disability weight of 0.336. The burden of OAE is approximately 13% of the total YLDs attributable to Onchocerciasis and 10% of total YLDs attributable to epilepsy. We estimated that by 2015 the total costs of treatment with anti-epileptic drug for OAE cases would have been a minimum of 12.4 million US$. Conclusions These estimates suggest a considerable health, social and economic burden of OAE in Africa. The treatment and care for people with epilepsy, especially in hyperendemic Onchocerciasis areas with high epilepsy prevalence thus requires more financial and human resources.
-
high prevalence of epilepsy in two rural Onchocerciasis endemic villages in the mahenge area tanzania after 20 years of community directed treatment with ivermectin
Infectious Diseases of Poverty, 2018Co-Authors: Bruno P Mmbando, Patrick Suykerbuyk, Mohamed Mnacho, Advocatus Kakorozya, William Matuja, Adam Hendy, Helena Greter, Williams H Makunde, Robert ColebundersAbstract:Epilepsy is a neurological disorder with a multitude of underlying causes, which may include infection with Onchocerca volvulus, the parasitic worm that causes human Onchocerciasis. A survey carried out in 1989 revealed a high prevalence of epilepsy (1.02% overall, ranging from 0.51 to 3.71% in ten villages) in the Mahenge area of Ulanga district, an Onchocerciasis endemic region in south eastern Tanzania. This study aimed to determine the prevalence and incidence of epilepsy following 20 years of Onchocerciasis control through annual community directed treatment with ivermectin (CDTI). The study was conducted in January 2017 in two suburban and two rural villages in the Mahenge area. Door-to-door household visits were carried out by trained community health workers and data assistants to screen for persons suspected of having epilepsy, using a standardised questionnaire. Persons with suspected epilepsy were then interviewed and examined by a neurologist for case verification. Onchocerciasis associated epilepsy was defined as epilepsy without an obvious cause, with an onset of seizures between the ages of 3–18 years in previously healthy children. In each village, fifty males aged ≥20 years were tested for Onchocerciasis antibodies using an OV16 rapid test and were examined for presence of Onchocerciasis nodules. Children aged 6–10 years were also tested using OV16 tests. 5117 individuals (median age 18.5 years, 53.2% female) from 1168 households were screened. 244 (4.8%) were suspected of having epilepsy and invited for neurological assessment. Prevalence of epilepsy was 2.5%, with the rural villages having the highest rate (3.5% vs 1.5%), P < 0.001. Overall incidence of epilepsy was 111 cases (95% CI: 73–161) per 100 000 person-years, while that of Onchocerciasis associated epilepsy was 131 (95% CI: 70–223). Prevalence of OV16 antibodies in adult males and among children 6–10 years old was higher in rural villages than in suburban villages (76.5% vs 50.6, and 42.6% vs 4.7% respectively), (P < 0.001), while overall prevalence of Onchocerciasis nodules was 1.8%. This survey revealed a high prevalence and incidence of epilepsy in two rural Onchocerciasis endemic villages in the Mahenge area. Despite 20 years of CDTI, a high prevalence of OV16 antibodies in children aged 6–10 years suggests on-going O. volvulus transmission. Reasons for the persistence of on-going parasite transmission in the Mahenge area need to be investigated.
-
Report of the first international workshop on Onchocerciasis-associated epilepsy.
Infectious Diseases of Poverty, 2018Co-Authors: Robert Colebunders, Michel Boussinesq, Sarah O'neill, An Hotterbeekx, Joseph Kamgno, Patrick Suykerbuyk, Michel Mandro, Alfred Njamnshi, Adrian Hopkins, María-gloria BasáñezAbstract:Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that Onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where Onchocerciasis is still endemic. MAIN TEXT: On October 12-14th 2017, the first international workshop on Onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries. Recent research findings strongly suggest that O. volvulus is an important contributor to epilepsy, particularly in meso- and hyperendemic areas for Onchocerciasis. Infection with O. volvulus is associated with a spectrum of epileptic seizures, mainly generalised tonic-clonic seizures but also atonic neck seizures (nodding), and stunted growth. OAE is characterised by an onset of seizures between the ages of 3-18 years. Multidisciplinary working groups discussed topics such as how to 1) strengthen the evidence for an association between Onchocerciasis and epilepsy, 2) determine the burden of disease caused by OAE, 3) prevent OAE, 4) improve the treatment/care for persons with OAE and affected families, 5) identify the pathophysiological mechanism of OAE, and 6) deal with misconceptions, stigma, discrimination and gender violence associated with OAE. An OAE Alliance was created to increase awareness about OAE and its public health importance, stimulate research and disseminate research findings, and create partnerships between OAE researchers, communities, advocacy groups, ministries of health, non-governmental organisations, the pharmaceutical industry and funding organizations. CONCLUSIONS: Although the exact pathophysiological mechanism underlying OAE remains unknown, there is increasing evidence that by controlling and eliminating Onchocerciasis, OAE will also disappear. Therefore, OAE constitutes an additional argument for strengthening Onchocerciasis elimination efforts. Given the high numbers of people with epilepsy in O. volvulus-endemic regions, more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.
-
report of the first international workshop on Onchocerciasis associated epilepsy
Infectious Diseases of Poverty, 2018Co-Authors: Robert Colebunders, Michel Boussinesq, Alfred K. Njamnshi, An Hotterbeekx, Joseph Kamgno, Patrick Suykerbuyk, Michel Mandro, Adrian Hopkins, Sarah Oneill, María-gloria BasáñezAbstract:Recently, several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that Onchocerciasis-associated epilepsy (OAE) may constitute an important but neglected public health problem in many countries where Onchocerciasis is still endemic. On October 12–14th 2017, the first international workshop on Onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium. The workshop was attended by 79 participants from 20 different countries. Recent research findings strongly suggest that O. volvulus is an important contributor to epilepsy, particularly in meso- and hyperendemic areas for Onchocerciasis. Infection with O. volvulus is associated with a spectrum of epileptic seizures, mainly generalised tonic-clonic seizures but also atonic neck seizures (nodding), and stunted growth. OAE is characterised by an onset of seizures between the ages of 3–18 years. Multidisciplinary working groups discussed topics such as how to 1) strengthen the evidence for an association between Onchocerciasis and epilepsy, 2) determine the burden of disease caused by OAE, 3) prevent OAE, 4) improve the treatment/care for persons with OAE and affected families, 5) identify the pathophysiological mechanism of OAE, and 6) deal with misconceptions, stigma, discrimination and gender violence associated with OAE. An OAE Alliance was created to increase awareness about OAE and its public health importance, stimulate research and disseminate research findings, and create partnerships between OAE researchers, communities, advocacy groups, ministries of health, non-governmental organisations, the pharmaceutical industry and funding organizations. Although the exact pathophysiological mechanism underlying OAE remains unknown, there is increasing evidence that by controlling and eliminating Onchocerciasis, OAE will also disappear. Therefore, OAE constitutes an additional argument for strengthening Onchocerciasis elimination efforts. Given the high numbers of people with epilepsy in O. volvulus-endemic regions, more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.
