Challenges in preparing and implementing a clinical trial at field level in an Ebola emergency: A case study in Guinea, West Africa.

During the large Ebola outbreak that affected West Africa in 2014 and 2015, studies were launched to evaluate potential treatments for the disease. A clinical trial to evaluate the effectiveness of the antiviral drug favipiravir was conducted in Guinea. This paper describes the main challenges of the implementation of the trial in the Ebola treatment center of Guéckédou. Following the principles of the Good Clinical Research Practices, we explored the aspects of the community's communication and engagement, ethical conduct, trial protocol compliance, informed consent of participants, ongoing benefit/risk assessment, record keeping, confidentiality of patients and study data, and roles and responsibilities of the actors involved. We concluded that several challenges have to be addressed to successfully implement a clinical trial during an international medical emergency but that the potential for collaboration between research teams and humanitarian organizations needs to be highlighted.

The diffuse infiltration of road runoff: an environmental improvement.

The Laboratory of Engineering and Environmental Geology (GEOLEP) has been mandated by Swiss authorities (Swiss Federal Road Office FedRO) to test a new road runoff management concept. This concept promotes the diffuse infiltration of road runoff into infiltration slopes designed for this purpose. Soils retain particles and contaminants; this lowers the road impact on the environment and simultaneously improves aquifer recharge. This concept has to be adapted to aquifer vulnerability and traffic conditions. Thus, a real-scale experimental station was designed and built in Switzerland to assess the feasibility of this new concept. This station allowed the testing of two lysimeters composed of 80 cm of A and B-horizons. Water and chemical fluxes were measured at the lysimeter bases. Road runoff was sampled in a distinct collector. Infiltration of road runoff into the local aquifer was monitored thanks to six piezometers. Water quality and quantity were therefore measured at each step of the infiltration process. Results provided by 112 natural events showed that soil horizons accommodated road runoff flows. The least favourable conditions for contaminant retention are encountered during thunderstorms, when high concentrations of substances deposited on the road are remobilised within a short time and rapidly percolates through soil horizons. Thus, three artificial events were designed to mimic heavy thunderstorms. Concentrations measured in road runoff notably decreased after soil filtration. Substances with high distribution coefficients Kd (low mobility) had concentrations reduced to lower values (1/1000 to 1/10,000), while those with high mobility retained similar concentrations even after soil filtration. However, these mobile substances exhibited low concentrations in the underlying aquifer due to dilution. This innovative road runoff management concept can thus be readily implemented outside groundwater protection zones where aquifers are slightly vulnerable; it undoubtedly lowers the environmental impact of roads, does not endanger road integrity, and locally increases aquifer recharge.