Studies on the morphometric characteristics of the Simulium damnosum complex in Uzo-Uwani, Enugu State, Nigeria

Studies on the morphometric characteristics of the Simulium vectors of onchocerciasis were carried out in Uzo-Uwani Local Government Area (LGA), Enugu State, Nigeria, between September 2008 and January 2009, with the objectives of identifying the sibling species present in the area and comparing the result obtained with cytological studies earlier done in the area. It was also meant to relate fly types with the types of onchocerciasis present in the area. The Simulium flies were collected using human baits. Seventy-five (75) flies were subjected to morphometric examinations. The thorax length, antenna length, wing length, wing width and femur length were measured and the data obtained were transformed into ratios. The morphometric studies on the Simulium damnosum populations in Nkpologu showed a higher abundance of savanna flies (54) than forest flies (21) among those sampled. The classification was done using the thorax length/antenna length (TL/AL) ratio. Discriminate function analysis revealed that 96.0% of originally grouped cases were correctly classified. The result agreed with cytotaxonomic studies on Simulium done in the area which showed predominance of savanna flies. The implications of the results are discussed

Understanding key vectors and vector-borne diseases associated with freshwater ecosystem across Africa: Implications for public health

The emerging and re-emerging vector-borne diseases transmitted by key freshwater organisms have remained a global concern. As one of the leading biodiversity hotspots, the African ecoregion is suggested to harbour the highest number of freshwater organisms globally. Among the commonly found organisms in the African ecoregion are mosquitoes and snails, with a majority of their life cycle in freshwater, and these freshwater organisms can transmit diseases or serve as carriers of devastating diseases of public health concerns. However, synthetic studies to link the evident abundant presence and wide distribution of these vectors across the freshwater ecosystems in Africa with the increasing emerging and re-emerging vector-borne diseases in Africa are still limited. Here, we reviewed documented evidence on vector-borne diseases and their transmission pathways in Africa to reduce the knowledge gap on the factors influencing the increasing emerging and re-emerging vector-borne diseases across Africa. We found the population distributions or abundance of these freshwater organisms to be increasing, which is directly associated with the increasing emerging and re-emerging vector-borne diseases across Africa. Furthermore, we found that although the current changing environmental conditions in Africa affect the habitats of these freshwater organisms, current changing environmental conditions may not be suppressing the population distributions or abundance of these freshwater organisms. Instead, we found that these freshwater organisms are extending their geographic ranges across Africa, which may have significant public health implications in Africa. Thus, our study demonstrates the need for future studies to integrate the environmental conditions of vectors' habitats to understand if these environmental conditions directly or indirectly influence the vectorial capacities and transmission abilities of vectors of diseases. We propose that such studies will be necessary to guide policymakers in making informed policies to help control vector-borne diseases

Local contextual factors of child stunting found via shared values of stakeholder groups: an exploratory case study in Kaffrine, Senegal

Abstract Objective: This work aims to demonstrate an original approach to identify links between locally-situated shared values and contextual factors of stunting. Stunting results from multi-factorial and multi-sectoral determinants, but interventions typically neglect locally-situated lived experiences, which contributes to problematic designs that are not meaningful for those concerned, and/or relatively ineffective. Design: This case study investigates relevant contextual factors in two steps: by first facilitating local stakeholder groups (n=11) to crystallize their shared-values-in-action using a specialised method from sustainability studies (WeValue_InSitu). Secondly, participants (n=44) have focus group discussions about everyday practices around child feeding/food systems, education, and/or family life. Because the first step strongly grounds participants in local shared values, the FGDs can reveal deep links between contextual factors and potential influences on stunting. Setting: Kaffrine, Senegal, an “Action Against Stunting Hub” site. December 2020. Participants: Eleven stakeholder groups of mothers, fathers, grandmothers, pre-school teachers, community health-workers, farmers, market traders, public administrators. Results: Local contextual factors of stunting were identified, including traditional beliefs concerning eating and growing practices; fathers as decision-makers; health worker trust; financial non-autonomy for women; insufficient water for preferred crops; merchants’ non-access to quality produce; religious teachings; and social structures affecting children’s food environment. Conclusions: Local contextual factors were identified. Pre-knowledge of these could significantly improve effectiveness of intervention designs locally, with possible applicability at other sites. The WeValue_InSitu approach proved efficient and useful for making tangible contextual factors and their potential links to stunting, via a lens of local shared values, showing general promise for intervention research