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International Health May 2020A high prevalence and incidence of epilepsy has been reported in onchocerciasis-endemic regions in Central and East Africa. There is compelling epidemiological evidence... (Meta-Analysis)
Meta-Analysis
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 in West African onchocerciasis foci.
METHODS
We searched PubMed, the African Journals Online platform and grey literature for population-based epilepsy studies in West African countries. Epilepsy and onchocerciasis prevalence data were extracted. The pre-control onchocerciasis endemicity in the study sites was 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 the West 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<0.001). Two studies in Ivory Coast that provided detailed descriptions of persons with epilepsy in onchocerciasis-endemic settings revealed that most of them had features of OAE (73.7% and 83.3%, respectively).
CONCLUSIONS
Our findings suggest that before and during the early years of implementing onchocerciasis control in West Africa, high onchocerciasis endemicity resulted in a high prevalence of OAE and that subsequent control efforts significantly reduced the prevalence of OAE.
Topics: Africa, Eastern; Africa, Western; Cote d'Ivoire; Epilepsy; Humans; Ivermectin; Onchocerciasis; Prevalence
PubMed: 32141502
DOI: 10.1093/inthealth/ihaa012 -
PLoS Neglected Tropical Diseases Jun 2009We sought to evaluate the relationship between onchocerciasis prevalence and that of epilepsy using available data collected at community level. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
We sought to evaluate the relationship between onchocerciasis prevalence and that of epilepsy using available data collected at community level.
DESIGN
We conducted a systematic review and meta-regression of available data.
DATA SOURCES
Electronic and paper records on subject area ever produced up to February 2008.
REVIEW METHODS
We searched for population-based studies reporting on the prevalence of epilepsy in communities for which onchocerciasis prevalence was available or could be estimated. Two authors independently assessed eligibility and study quality and extracted data. The estimation of point prevalence of onchocerciasis was standardized across studies using appropriate correction factors. Variation in epilepsy prevalence was then analyzed as a function of onchocerciasis endemicity using random-effect logistic models.
RESULTS
Eight studies from west (Benin and Nigeria), central (Cameroon and Central African Republic) and east Africa (Uganda, Tanzania and Burundi) met the criteria for inclusion and analysis. Ninety-one communities with a total population of 79,270 individuals screened for epilepsy were included in the analysis. The prevalence of epilepsy ranged from 0 to 8.7% whereas that of onchocerciasis ranged from 5.2 to 100%. Variation in epilepsy prevalence was consistent with a logistic function of onchocerciasis prevalence, with epilepsy prevalence being increased, on average, by 0.4% for each 10% increase in onchocerciasis prevalence.
CONCLUSION
These results give further evidence that onchocerciasis is associated with epilepsy and that the disease burden of onchocerciasis might have to be re-estimated by taking into account this relationship.
Topics: Africa; Endemic Diseases; Epilepsy; Humans; Onchocerciasis; Prevalence
PubMed: 19529767
DOI: 10.1371/journal.pntd.0000461 -
The Israel Medical Association Journal... Jul 2003
Topics: Emigration and Immigration; Ethiopia; Humans; Israel; Onchocerciasis
PubMed: 12901252
DOI: No ID Found -
Medecine Et Sante Tropicales Feb 2019While Eugène Jamot's name is associated with the combat against sleeping sickness, Pierre Richet is permanently linked to the battle against river blindness, which he...
While Eugène Jamot's name is associated with the combat against sleeping sickness, Pierre Richet is permanently linked to the battle against river blindness, which he first reported in 1936 in two neighboring households in Garango (Burkina Faso). Onchocerciasis remained a continuous interest, through his last article "The OCCGE and Onchocerciasis", written in 1983. Nonetheless over the course of these five decades, Richet's trajectory was far from that of a specialist dedicating his life to a single disease. After a decade essentially spent fighting trypanosomiasis, came a decade of war in which the specialist in endemism joined the Free French Army and put his organizational know-how at General Lerclerc's disposal, from Morocco to Indochina, via Germany. On his return to Africa in 1953, he extended the principle of mobile teams to the other major endemic diseases accessible to treatment and to vaccines. Richet organized first the combat against leprosy and launched vaccination programs. In 1955, he returned to the battle against onchocerciasis and deployed the first large-scale insecticide program in Chad. The intermediate term failure of this prototype fermented his scientific, interdisciplinary, and organizational thought, which flourished at Bobo-Dioulasso. At the dawn of the independence of French-speaking African countries, and against the political tides of the time, he obtained in 1960 the creation of a supranational organization, the OCCGE, common to 8 countries of West Africa, and he headed it for a decade. Drawing lessons from the past and in the absence of effective pharmaceutical treatment, Richet the physician played the entomological card with one hand, with technical support from Orstom (IRD); this detailed work enabled the development of a strategy. With the other hand, he played the multilateral card, which led in 1974 to the launching of the extraordinary Onchocerciasis Control Program (OCP). If it is Jamot who awakened Africa, Richet is the person who restored its view but also millions of hectares of cultivable land.
Topics: Africa; Endemic Diseases; France; History, 20th Century; Humans; Onchocerciasis
PubMed: 31031236
DOI: 10.1684/mst.2019.0871 -
Parasites & Vectors Apr 2017Loiasis is a filarial disease caused Loa loa. The main vectors are Chrysops silacea and C. dimidiata which are confined to the tropical rainforests of Central and West... (Review)
Review
BACKGROUND
Loiasis is a filarial disease caused Loa loa. The main vectors are Chrysops silacea and C. dimidiata which are confined to the tropical rainforests of Central and West Africa. Loiasis is a mild disease, but individuals with high microfilaria loads may suffer from severe adverse events if treated with ivermectin during mass drug administration campaigns for the elimination of lymphatic filariasis and onchocerciasis. This poses significant challenges for elimination programmes and alternative interventions are required in L. loa co-endemic areas. The control of Chrysops has not been considered as a viable cost-effective intervention; we reviewed the current knowledge of Chrysops vectors to assess the potential for control as well as identified areas for future research.
RESULTS
We identified 89 primary published documents on the two main L. loa vectors C. silacea and C dimidiata. These were collated into a database summarising the publication, field and laboratory procedures, species distributions, ecology, habitats and methods of vector control. The majority of articles were from the 1950-1960s. Field studies conducted in Cameroon, Democratic Republic of Congo, Equatorial Guinea, Nigeria and Sudan highlighted that C. silacea is the most important and widespread vector. This species breeds in muddy streams or swampy areas of forests or plantations, descends from forest canopies to feed on humans during the day, is more readily adapted to human dwellings and attracted to wood fires. Main vector targeted measures proposed to impact on L. loa transmission included personal repellents, household screening, indoor residual spraying, community-based environmental management, adulticiding and larviciding.
CONCLUSIONS
This is the first comprehensive review of the major L. loa vectors for several decades. It highlights key vector transmission characteristics that may be targeted for vector control providing insights into the potential for integrated vector management, with multiple diseases being targeted simultaneously, with shared human and financial resources and multiple impact. Integrated vector management programmes for filarial infections, especially in low transmission areas of onchocerciasis, require innovative approaches and alternative strategies if the elimination targets established by the World Health Organization are to be achieved.
Topics: Animal Distribution; Animals; Diptera; Disease Eradication; Ecology; Humans; Insect Vectors; Loa; Loiasis; Onchocerciasis
PubMed: 28381279
DOI: 10.1186/s13071-017-2103-y -
Molecular & Cellular Proteomics : MCP Jan 2023Onchocerca volvulus, the causative agent of onchocerciasis, infects over 20 million people and can cause severe dermatitis and ocular conditions including blindness.... (Review)
Review
Onchocerca volvulus, the causative agent of onchocerciasis, infects over 20 million people and can cause severe dermatitis and ocular conditions including blindness. Current treatments employed in mass drug administration programs do not kill adult female worms, and common diagnostic tests cannot reliably assess viability of adult worms. There is an urgent need for better diagnostic tests to facilitate monitoring the efficacy of new treatments and disease elimination efforts. Here, eight plasma samples collected from individuals infected with O. volvulus and seven from uninfected individuals were analyzed by MS/MS spectrometry to directly identify O. volvulus proteins present in infected but absent in uninfected control samples. This direct proteomic approach for biomarker discovery had not been previously employed for onchocerciasis. Among all detected proteins, 19 biomarker candidates were supported by two or more unique peptides, identified in the plasma of at least three O. volvulus-infected human samples and absent in all control samples. Comprehensive analysis and ranking of these candidates included detailed functional annotation and a review of RNA-seq gene expression profiles. Isotope-labeled standard peptides were run in parallel and validated MS/MS peptide identifications for 15 peptides from 11 of the 19 proteins, and two infected urine and one uninfected urine sample was used for additional validation. A major antigen/OVOC11613 was identified as the most promising candidate with eight unique peptides across five plasma samples and one urine sample. Additional strong candidates included OVOC1523/ATP synthase, OVOC247/laminin and OVOC11626/PLK5, and along with OVOC11613, and were also detected in urine samples from onchocerciasis patients. This study has identified a promising novel set of proteins that will be carried forward to develop assays that can be used for diagnosis of O. volvulus infections and for monitoring treatment efficacy.
Topics: Humans; Biomarkers; Intestinal Volvulus; Onchocerciasis; Proteomics; Tandem Mass Spectrometry
PubMed: 36435333
DOI: 10.1016/j.mcpro.2022.100454 -
Epilepsy & Behavior : E&B Feb 2022To assess the community's perception of epilepsy and its treatment in onchocerciasis-endemic villages of Maridi County, Western Equatoria State, South Sudan. The study...
OBJECTIVE
To assess the community's perception of epilepsy and its treatment in onchocerciasis-endemic villages of Maridi County, Western Equatoria State, South Sudan. The study was conducted prior to the setting up of a community-based intervention to manage the important disease burden caused by onchocerciasis-associated epilepsy in these villages.
METHOD
Five focus group discussions (FGD) were conducted with community leaders and with persons with epilepsy (PWE) and their families between November and December 2019.
RESULTS
Villages close to the Maridi dam were considered to be most affected by epilepsy. Misconceptions about the cause and treatment of epilepsy were identified. Most people believed that epilepsy is caused by bad spirits and is contagious, transmitted through saliva, air, and contact with PWE. Very few participants were aware of the link between onchocerciasis and epilepsy. Persons with epilepsy are restricted in their day-to-day activities and children with epilepsy are often denied going to school. Persons with epilepsy are stigmatized and seen as unfit for marriage. Most participants considered both traditional and medical treatment as ineffective. Uninterrupted anti-seizure treatment continuously was unaffordable for most families with one or more PWE.
CONCLUSION
There is a need to establish a comprehensive epilepsy treatment program which addresses misconceptions about epilepsy and reduces epilepsy-related stigma. Explaining the link between onchocerciasis and epilepsy could lead to a reduction in epilepsy-related stigma.
Topics: Child; Epilepsy; Humans; Onchocerciasis; Perception; Seizures; South Sudan
PubMed: 35026562
DOI: 10.1016/j.yebeh.2021.108537 -
Parasites & Vectors Jun 2022Integrated transmission assessment surveys (iTAS) have been recommended for evaluation of the transmission of both lymphatic filariasis (LF) and onchocerciasis as the...
BACKGROUND
Integrated transmission assessment surveys (iTAS) have been recommended for evaluation of the transmission of both lymphatic filariasis (LF) and onchocerciasis as the prevalence of both diseases moves toward their respective elimination targets in Nigeria. Therefore, we conducted an iTAS between May and December 2017 in five local government areas (LGAs), also known as implementation units (IUs), in states of Cross River, Taraba and Yobe in Nigeria.
METHODS
The TAS comprised two phases: the Pre-iTAS and the iTAS itself. Three states (Cross River, Taraba and Yobe), comprising five LGAs and 20 communities that have completed five rounds of combined treatment with ivermectin and albendazole for LF and 12 total rounds of ivermectin, were selected for inclusion in the study. All participants were tested with the Filariasis Test Strip (FTS; Alere Inc.) and the Biplex rapid Diagnostic Test (RDT; identifying filaria antigens Ov16/Wb123; Abbott diagnosctics Korea Inc.). Pre iTAS included 100 children ages 5-9 in each 4 communities and 300 individuals ages 10 and older in a subset of two communities. For the iTAS, only LGAs where antigenemia prevalence in all sampled communities during the Pre-iTAS was < 2% for LF were selected.
RESULTS
Of the five LGAs included in the study, four met the cutoff of the Pre-iTAS and were included in the iTAS; the Ikom LGA was excluded from the iTAS due to antigenemia prevalence. A total of 11,531 school-aged children from 148 schools were tested for LF and onchocerciasis across these four LGAs, including 2873 children in Bade, 2622 children in Bekwara, 3026 children in Gashaka and 3010 children in Karim Lamido. Using the FTS, all samples from Bade and Karim Lamido were negative, whereas 0.2% of the samples from Bekwara and Gashaka were positive. Using the Biplex RDT, LF prevalence in Bade, Bekwara, Gashaka and Karim Lamido was < 0.1%, 0.5%, 0.4% and < 0.1%, respectively. Moreover, all samples from Bade and Karim Lamido were negative for onchocerciasis, whereas 3.1% and 1.8% of the samples from Bekwara and Gashaka were positive, respectively.
CONCLUSION
This study has provided additional information on the current burden of onchocerciasis and LF in the four IUs sampled where mass drug administration (MDA) for both infections has been ongoing for years. The study identifies that LF-MDA can be safely stopped in all four of the IUs studied, but that MDA for onchocerciasis needs to continue, even though this may pose a challenge for LF surveillance. Based on the preliminary results from all four sites, this study has fulfilled the primary objective of determining the programmatic feasibility of an iTAS as a tool to simultaneously assess onchocerciasis and LF prevalence in areas co-endemic for the two infections that have completed the recommended treatment for one or both infections, and to make decisions on how to proceed.
Topics: Albendazole; Child; Child, Preschool; Elephantiasis, Filarial; Humans; Ivermectin; Nigeria; Onchocerciasis; Prevalence
PubMed: 35698164
DOI: 10.1186/s13071-022-05302-x -
Parasites & Vectors Oct 2021Despite high black fly densities in persisting onchocerciasis foci in Cameroon, no vector control has ever been carried out to complement Community-Directed Treatment...
Knowledge/perception and attitude/practices of populations of two first-line communities of the Centre Region of Cameroon regarding onchocerciasis and black fly nuisance and bio-ecology.
BACKGROUND
Despite high black fly densities in persisting onchocerciasis foci in Cameroon, no vector control has ever been carried out to complement Community-Directed Treatment with Ivermectin (CDTI). As a prelude to community-based vector control, this study explored knowledge/perception and attitude/practice (KAP) of populations of two first-line communities regarding onchocerciasis, black fly nuisance and bio-ecology.
METHODS
A cross-sectional survey was conducted in two communities of the Bafia Health District, following a household-based interview approach using a structured questionnaire. KAP scores were calculated and categorised as good or poor based on the number of correct or positive responses. Associations between KAP and socio-demographic parameters were explored using logistic regression models.
RESULTS
A total of 215 individuals aged 15-100 years were interviewed. Positive associations were observed between good knowledge/perception and age and the duration of residency in the community. Most respondents (91.6%) described having post-biting sequels (oedema, itching) and more than half (69.3%) admitted that black fly bites affect their productivity. Although 81.4% of the respondents stated that black fly densities are higher during the rainy season, only 10.7% of them knew that they breed in the river. Also, 59.5% of the interviewees stated that black flies bite not only outdoors but also indoors, and 78.6% of enrolees were ready to help to fight against black flies. Most of the respondents were well aware of onchocerciasis, even though the transmission mode and vector bio-ecology were not well known.
CONCLUSION
This study revealed the need to implement community-based vector control to support CDTI in the fight against onchocerciasis and to reduce black fly nuisance.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antiparasitic Agents; Cameroon; Cross-Sectional Studies; Endemic Diseases; Female; Health Knowledge, Attitudes, Practice; Humans; Ivermectin; Logistic Models; Male; Middle Aged; Onchocerciasis; Perception; Public Health; Seasons; Simuliidae; Surveys and Questionnaires; Young Adult
PubMed: 34688311
DOI: 10.1186/s13071-021-05048-y -
Parasites & Vectors Oct 2011Onchocerciasis (river blindness) is a blinding parasitic disease that threatens the health of approximately 120 million people worldwide. While 99% of the population... (Review)
Review
Onchocerciasis (river blindness) is a blinding parasitic disease that threatens the health of approximately 120 million people worldwide. While 99% of the population at-risk for infection from onchocerciasis live in Africa, some 500,000 people in the Americas are also threatened by infection. A relatively recent arrival to the western hemisphere, onchocerciasis was brought to the New World through the slave trade and spread through migration. The centuries since its arrival have seen advances in diagnosing, mapping and treating the disease. Once endemic to six countries in the Americas (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela), onchocerciasis is on track for interruption of transmission in the Americas by 2012, in line with Pan American Health Organization resolution CD48.R12. The success of this public health program is due to a robust public-private partnership involving national governments, local communities, donor organizations, intergovernmental bodies, academic institutions, non-profit organizations and the pharmaceutical industry. The lessons learned through the efforts in the Americas are in turn informing the program to control and eliminate onchocerciasis in Africa. However, continued support and investment are needed for program implementation and post-treatment surveillance to protect the gains to-date and ensure complete elimination is achieved and treatment can be safely stopped within all 13 regional foci.
Topics: Americas; Communicable Disease Control; Humans; Onchocerciasis; Public Health
PubMed: 22024050
DOI: 10.1186/1756-3305-4-205