Ivermectin treatment response in two rural villages with a high prevalence of onchocerciasis and epilepsy, Mahenge Tanzania

Background: Despite 20 years of ivermectin mass distribution in the Mahenge area, Tanzania, the prevalence of onchocerciasis and epilepsy has remained high in rural villages. Objectives: We investigated the efficacy of ivermectin in reducing Onchocerca volvulus microfilariae and predictors for parasitic load following ivermectin treatment in persons with (PWE) and without epilepsy (PWOE). Methods: Between April and September 2019, 50 PWE and 160 randomly selected PWOE from Msogezi and Mdindo villages participated in a follow-up study. Skin snips were obtained pre (baseline) and three months post-ivermectin treatment. Results: The overall prevalence of O. volvulus positive skin snips at baseline was 49% (103/210), with no significant difference between PWE (58.0%) and PWOE (46.3%); p=0.197. The overall mean micro filarial density was significantly higher at baseline 1.45(95%CI:0.98-2.04)) than three-month post-ivermectin treatment (0.23(95%CI:0.11-0.37), p<0.001. Three months after ivermectin, the micro filarial density had decreased by ≥80% in 54 (81.8%, 95%CI: 72.3-91.4) of the 66 individuals with positive skin snips at baseline. High micro filarial density at baseline was the only significant predictor associated with higher micro filarial density in the post-ivermectin skin snips. Conclusion: Our study reports a decrease in micro filarial density following ivermectin treatment in most individuals. Optimizing ivermectin coverage will address the ongoing onchocerciasis transmission in Mahenge

Knowledge, attitudes, and practices toward onchocerciasis among local population in Bioko Island, Equatorial Guinea

Introduction: Since 1998, the African program for onchocerciasis control has been working with ultimate goal of reducing the public health impact associated with onchocerciasis in Equatorial Guinea. Although dedicated community engagement is crucial for the success of this program, there is no information on the levels of community's knowledge, attitude, and practice (KAP) toward onchocerciasis in this country. Methods: A cross-sectional study was carried out in Bioko Island from mid-January to mid-February 2014. Sampling was carried out by multistage cluster survey. Sociodemographic characteristics, KAP, and stigma-related questions were collected through a pretested questionnaire. A bivariate analysis was performed and results were adjusted by sex and age using logistic regression. Results: A total of 140 housekeepers or head of households agreed to participate. Around 54% of the interviewees had heard about the disease, of which more than one-third identified the disease as filariasis (28/68, 41.2%). Overall, 19.3% respondents highlighted the bite of a blackfly as the main mode of transmission. From those who had a familiar affected by onchocerciasis in the past, 21 out of 32 (65.6%) pointed ivermectin as the preferred treatment and 43.8% pointed out the health center as the first choice place to seek for treatment. About 67.1% of individuals believed that having onchocerciasis would not cause any contact avoidance with other members in the community. Conclusions: People's practices toward onchocerciasis tend to be better than disease knowledge in Bioko Island. Increasing awareness through community-based campaigns and educational activities is encouraged in the current onchocerciasis preelimination stage at Bioko Island

Lesions oculaires de l'onchocercose et observance au Traitement a L'ivermectine Sous Directives Communautaires (TIDC)

BUT: Determiner si les complications oculaires de l'onchocercose influencaient l'observance des patients au TIDC. MATeRIELS ET MeTHODES: Nous avons mene une etude transversale descriptive dans la region du Littoral au Cameroun. Etaient inclus dans cette etude tous les sujets ages d'au moins 10 ans. Les variables etudiees etaient l'acuite visuelle; le type de deficience visuelle; le sexe; les lesions oculaires d'onchocercose; le nombre de prises d'Ivermectine au cours des 5 dernieres annees. ReSULTATS : Nous avons collige 764 patients soit 1528 yeux. Le nombre d'yeux presentant des lesions d'onchocercose etait de 56 et ceux n'en presentant pas etaient au nombre de 1472. Nous avons releve une prevalence de 48 de bonne observance au TIDC au sein de la population generale. Mais nous avons retrouve une prevalence de 57 de bonne observance chez les cas contre une prevalence de 48 chez les controles (P = 0;28). Une similarite dans la regularite de la prise de l'Ivermectine entre les femmes et les hommes a ete retrouvee. CONCLUSION :Les patients presentant des lesions oculaires de l'onchocercose ont majoritairement une bonne observance au TIDC dans la region du Littoral contrairement a ceux ne presentant pas de lesions oculaires de l'onchocercose. Le genre n'est pas un facteur influencant l'observance au TIDC dans notre etude contrairement a certaines donnees de la litterature. Le nombre de prises d'Ivermectine n'est pas un facteur predisposant les hommes aux atteintes oculaires de l'onchocercose. En cas d'absence de deficience Visuelle les patients avec des lesions oculaires de l'onchocercose ont une meilleure observance au TIDC. La presence de lesions oculaires de l'onchocercose semble etre un facteur motivant les patients atteints a une meilleure observance au TIDC

Transmission de l'onchocercose par Simulium squamosum (Diptera : Simuliidae) dans le foyer urbain de Kinsuka a Kinshasa/Republique democratique du Congo

Contexte. Les etudes realisees dans le foyer de Kinsuka entre 1985 et 2001 ont montre une tendance a la reemergence de la transmission de l'onchocercose dans ce foyer. Le but de la presente etude exploratoire etait de determiner le niveau actuel de la transmission de cette parasitose; en vue d'apprehender des facteurs explicatifs du niveau d'endemicite constate. Methodes. Les simulies ont ete capturees dans deux points de capture (P1 et P2); pour une periode de 12 mois (mars 2008-fevrier 2009); par le procede classique de capture sur appats humains. Dans l'ensemble; 82;1des simulies capturees ont ete dissequees pour la determination de la parite; et toutes les simulies pares ont ete dissequees pour denombrer les larves d'O. volvulus. Les autres especes de simulies ont ete inventoriees; et les supports larvaires ont ete prospectes. Resultats. Au total; 12282 simulies ont ete capturees dont 5018 au S1; et 7264 au S2. Le cycle d'agressivite journaliere a presente une courbe concave avec deux pics; dont un mineur entre 8 et 9 heures; et un majeur entre 17h et 18h. Dans l'ensemble de simulies dissequees; 42;4etaient pares. Seules 25 simulies pares etaient infectees par les larves d'O. volvulus; dont 14 au S1; et 11 au S2. Une seule simulie etait infectante. Les taux annuels de piqures (TAP) etaient de 564453; et 78111 piqures par personne par an respectivement. Le potentiel de transmission est pratiquement nul : 0 au S1; et 28 larves infectantes par personne par an au S2. Conclusion. Le taux d'agressivite est environ 12 fois plus eleve que celui observe il y a 27 ans; dans le meme site. Le taux observe est en partie du a l'influence des activites realisees par la nouvelle entreprise d'exploitation de moellons dans la carriere de Kinsuka. Ces activites ont provoque entre autres; le retrecissement du lit du fleuve pendant la saison seche; qui entraine une augmentation du niveau du fleuve; creant une grande disponibilite des supports larvaires. La transmission de l'onchocercose est presque nulle. Des etudes ulterieures permettront d'en identifier les determinants

Utility and Effectiveness of Computerised Motion Sensitivity Screening Tests in Rural Onchocercal Community Survey

BACKGROUND: Non-invasive tool of community diagnosis for onchocercal endemicity needs to be identified and ascertained for their utility and effectivity in order to facilitate the control of onchocerciacis in sub-Saharan Africa OBJECTIVE: To determine the utility and effectiveness of the Wu-Jones Motion Sensitivity Screening Test (MSST) in detecting optic nerve diseases in onchocercal-endemic rural Africa. METHODS: MSST was applied to sampled subjects in the selected communities of Raja in Sudan; Bushenyi in Uganda; Morogoro in Tanzania; and of Ikom; Olamaboro and Gashaka in Nigeria. Basically; six points within the central field of vision were repeatedly tested at 1/3 meter from the screen of a laptop computer in a room darkened. Motion sensitivity was expressed as a percentage of motion detected in the individual eye and this was averaged for the community. RESULTS: A total of 3;858 eyes of 2;072 patients were examined. Seventy-six percent of the subjects completed the test; at an average test time of 120.4 (66.7) seconds. The overall mean motion sensitivity of all eyes tested was 88.49 (17.49). At a cut-off point of 50; 6.4of all subjects tested were subnormal; while at 70cutoff; 13.3were subnormal. The highest proportion of 50cutoff sub-normality was recorded at Morogoro at 12.7. CONCLUSION: Motion Sensitivity Screening Test was widely accepted and easily administered to the rural and largely illiterate subjects studied. Our data suggest that the proportion of severe field defects by MSST in a community; with cutoff at 33; best correlates with optic nerve disease prevalence; while proportion of defect from a higher cut-off level at about 50; best correlates with overall ocular morbidity

Community-directed interventions for priority health problems in Africa: results of a multicountry study

Objective To determine the extent to which the community-directed approach used in onchocerciasis control in Africa could effectively and efficiently provide integrated delivery of other health interventions.Methods A three-year experimental study was undertaken in 35 health districts from 2005 to 2007 in seven research sites in Cameroon; Nigeria and Uganda. Four trial districts and one comparison district were randomly selected in each site. All districts had established ivermectin treatment programmes; and in the trial districts four other established interventions - vitamin A supplementation; use of insecticide-treated nets; home management of malaria and short-course; directly-observed treatment for tuberculosis patients - were progressively incorporated into a community-directed intervention (CDI) process. At the end of each of the three study years; we performed quantitative evaluations of intervention coverage and provider costs; as well as qualitative assessments of the CDI process. Findings With the CDI strategy; significantly higher coverage was achieved than with other delivery approaches for all interventions except for short-course; directly-observed treatment. The coverage of malaria interventions more than doubled. The district-level costs of delivering all five interventions were lower in the CDI districts; but no cost difference was found at the first-line health facility level. Process evaluation showed that: (i) participatory processes were important; (ii) recurrent problems with the supply of intervention materials were a major constraint to implementation; (iii) the communities and community implementers were deeply committed to the CDI process; (iv) community implementers were more motivated by intangible incentives than by external financial incentives. Conclusion The CDI strategy; which builds upon the core principles of primary health care; is an effective and efficient model for integrated delivery of appropriate health interventions at the community level in Africa