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.

Macro problems from microplastics: Toward a sustainable policy framework for managing microplastic waste in Africa.

Microplastic pollution is a ubiquitous and emerging environmental and public health concern in Africa due to increased plastic production, product and waste importation, and usage. While studies on the environmental monitoring and characterization of microplastics demonstrated the urgent need for a drastic reduction in plastic waste generation, the effectiveness of the various regulatory and policy interventions implemented or proposed in Africa countries remains poorly understood. We critically examined policies, legislations, and regulations enacted to control microplastic pollution in Africa to develop a sustainable, harmonized framework for the coordinated reduction of plastic waste generation across Africa. Analysis of the interventions revealed most African countries employed traditional perspective (i.e., command-and-control) approaches, whereby state instruments such as plastic ban, production and importation levies, and consumer taxes were enacted. However, the continued increase in microplastic waste generation suggests traditional perspective approaches might not be effective in Africa. Although rarely used in Africa, market-oriented approaches such as private-public waste management are often effective in controlling plastic pollution. Hence, we proposed a bottom-up hybrid regulatory approach for managing microplastics pollution in Africa, involving price-based, right-base, legislation and behavioral frameworks based on best practices in microplastic waste management.

Another insight into the contamination levels at Ogoniland in Niger Delta, Nigeria, with focus on Goi Creek.

Environmental pollution arising from crude oil exploratory activities has adversely impacted both the living and non-living components of the ecosystem. An insight into the impact of such activities with focus on Goi Creek in Ogoniland was provided in this study. We generated reliable data for physicochemical, heavy metal, and total hydrocarbon levels in the creek via a total of 40 samples collected across 4 stations designated within the creek in a duration of 10 months. With the exception of temperature, total dissolve solid, dissolved oxygen, chloride, sulfate, nitrate, zinc, and vanadium, the levels of other regulated parameters in the samples were not compatible with the national and international guidelines and standards for surface water quality including Federal Ministry of Environment Guidelines and standards for water quality in Nigeria and Environmental Protection Agency National recommended water quality criteria, respectively. The principal components (PCs) 1 and 2 of principal component analysis biplot revealed that the concentrations of the physicochemical parameters showed a mixed distribution among the stations; however, the heavy metals were more localized to station 4. Moreover, the dataset was subjected to water quality index (WQI), contamination index (Cd), heavy metal evaluation index (HEI), trace element toxicity index (TETI), and environmental water quality index (EWQI) to determine the extent of contamination. The result showed poor WQI, high contamination for Cd, and low-to-medium contamination for HEI. Although, there were variations among the stations on the contamination level, uniform remediation method should be adopted due to the similarity of the contaminants in all the stations.

Phylogeography and genetic diversity of the copepod family Cyclopidae (Crustacea: Cyclopoida) from freshwater ecosystems of Southeast Nigeria.

BACKGROUND: Copepods are key components of aquatic ecosystems and can help regulate the global carbon cycle. Much attention has been paid to the species diversity of copepods worldwide, but the phylogeography and genetic diversity of copepods in Nigeria is unexplored. RESULTS: Using a mitochondrial cytochrome c oxidase subunit I marker, we preformed phylogenetic and phylogeographic analyses for Cyclopidae copepods in Southeast Nigeria. A high species diversity of Cyclopidae in Nigeria: 5 species of Tropocyclops, 5 species of Mesocyclops and 2 species of Thermocyclops from Cyclopidae were identified in 15 populations. Moreover, we detected 18 unique haplotypes, which fell into two distinct clades. Pairwise genetic distances (uncorrected p-distances) among the species of Cyclopidae ranged from 0.05 to 0.257. Several species co-existed in the same lake, and some haplotypes were shared among different geographic populations, suggesting a dispersal of Cyclopidae in our sampling region. Finally, we found that the population genetic diversity for each species of Cyclopidae was low in Nigeria. CONCLUSIONS: Our findings explored the species diversity and distribution of copepods within the family Cyclopidae for 15 Nigerian freshwater ecosystems: a high species diversity of Cyclopidae copepods was detected over a small geographic sampling range. Results from this study contribute to a better understanding of copepod diversity of Nigerian freshwater ecosystems.