RESUMO
Artisanal small-scale mining is widely operated in various countries serving as a livelihood to many rural communities. However, it is a significant source of environmental mercury contamination which affects human health. Amalgamation and amalgam smelting, two significant steps in the artisanal small-scale mining operations generate lots of mercury vapors, leading to chronic exposure among miners. Thus, this article seeks to provide a topical review of recent findings on organ damage and metabolic disorders among mercury-exposed artisanal small-scale miners with emphasis on the contributing factors such as personal protective equipment usage and artisanal small-scale gold mining-specific occupational activities. Also, insights into the effect of mercury intoxication and mechanisms of action on organ and metabolic systems among exposed individuals are provided.
RESUMO
To avoid unnecessary waste of limited resources and to help prioritize areas for conservation efforts, this study aimed to provide information on habitat use by elephants between the wet and dry seasons in the Mole National Park (MNP) of Ghana. We compiled coordinates of 516 locations of elephants' encounters, 256 for dry season and 260 for wet season. Using nine predictor variables, we modeled the probability of elephant's distribution in MNP. We threshold the models to "suitable" and "nonsuitable" regions of habitat use using the equal training sensitivity and specificity values of 0.177 and 0.181 for the dry and wet seasons, respectively. Accuracy assessment of our models revealed a sensitivity score of 0.909 and 0.974, and a specificity of 0.579 and 0.753 for the dry and wet seasons, respectively. A TSS of 0.488 was also recorded for the dry season and 0.727 for the wet season indicating a good model agreement. Our model predicts habitat use to be confined to the southern portion of MNP due to elevation difference and a relatively steep slope that separates the northern regions of the park from the south. Regions of habitat use for the wet season were 856 km2 and reduced significantly to 547.68 km2 in the dry season. We observed significant overlap (327.24 km2) in habitat use regions between the wet and dry seasons (Schoener's D = 0.922 and Hellinger's-based I = 0.991). DEM, proximity to waterholes, and saltlicks were identified as the key variables that contributed to the prediction. We recommend construction of temporal camps in regions of habitat use that are far from the headquarters area for effective management of elephants. Also, an increase in water point's density around the headquarters areas and selected dry areas of the park will further decrease elephant's range and hence a relatively less resource use in monitoring and patrols.
RESUMO
BACKGROUND: To fully understand the burden of hepatitis C (HCV) infection in Ghana towards informing appropriate preventive measures, accurate prevalence estimates are needed. In this study, we estimate the prevalence of chronic HCV infection by systematically reviewing primary studies published between 1995 and 2015. METHODS: A systematic review and meta-analysis was conducted as per the PRISMA guidelines. Comprehensive searches for hepatitis C prevalence studies for the years 1995-2015 were conducted in PubMed, ScienceDirect, Google Scholar, Africa Journals Online (AJOL) and the WHO African Index Medicus databases. We also searched the websites of the ministry of health and Ghana Health service for non-indexed studies or reports on the subject. Further systematic reference screening of published reviews and retrieved studies were also conducted to identify additional publications not captured through the online searches. RESULTS: Twenty-Four (24) studies from nine regions of Ghana with a combined sample size of 100,782 were analyzed. No study involving participants from Upper West region was retrieved. The national prevalence of chronic HCV was estimated as 3.0 % (95 % CI = 2.6 % to 3.5 %; I(2) = 97.61 %, p < 0. 001). Prevalence rates of chronic HCV infection among blood donors was 2.6 % (95 % CI = 2.1 % to 3.1 %; I(2) = 98.33 %, p < 0.001) with higher prevalence rate estimated for replacement blood donors (RBDs) than voluntary blood donors (RBDs). Among pregnant women and parturients, anti-HCV seroprevalence was estimated as 4.6 % (95 % CI = 1.8 % to 7.5 %; I(2) = 75.74 %, p = 0.016). The national prevalence of HIV/HCV co-infection was also estimated as 2.8 % (95 % CI = 0.4-6 %; I(2) = 65.86 %, p = 0.0053). Regional prevalence of chronic HCV infection were determined for Ashanti (1.5 %, 95 % CI = 1.2 % to 1.9 %; I(2) = 96.24 %, p < 0.001) and Greater Accra (6.4 %, 95 % CI = 4.2 % to 8.6 %; I(2) = I(2) = 88.5 %, P < 0. 001) regions but no estimates were available for the other eight regions. The ascending order of HCV prevalence rates according to years in which studies were conducted was 2006-2010 < 2011-2015 < 1995-2002 < 2001-2005. Higher prevalence of chronic HCV infection was estimated for rural (5.7; 95 % CI 5.0-6.3 %; I(2) = 0, p = 0.804) than urban (2.6 %, 95 % CI = 2.1 % to 3.0 %; I(2) = 97.3 %, p = 0.0001) settings. CONCLUSION: Our study demonstrates a high prevalence of chronic hepatitis C infection in Ghana. This highlights the urgent need for stronger commitments from government and all stakeholders within the country to outline efficient preventive and curative measures towards reducing the overall burden of the disease.
