Temporally consistent predominance and distribution of secondary malaria vectors in the Anopheles community of the upper Zambezi floodplain.

Regional optimisation of malaria vector control approaches requires detailed understanding both of the species composition of Anopheles mosquito communities, and how they vary over spatial and temporal scales. Knowledge of vector community dynamics is particularly important in settings where ecohydrological conditions fluctuate seasonally and inter-annually, such as the Barotse floodplain of the upper Zambezi river. DNA barcoding of anopheline larvae sampled in the 2019 wet season revealed the predominance of secondary vector species, with An. coustani comprising > 80% of sampled larvae and distributed ubiquitously across all ecological zones. Extensive larval sampling, plus a smaller survey of adult mosquitoes, identified geographic clusters of primary vectors, but represented only 2% of anopheline larvae. Comparisons with larval surveys in 2017/2018 and a contemporaneous independent 5-year dataset from adult trapping corroborated this paucity of primary vectors across years, and the consistent numerical dominance of An. coustani and other secondary vectors in both dry and wet seasons, despite substantial inter-annual variation in hydrological conditions. This marked temporal consistency of spatial distribution and anopheline community composition presents an opportunity to target predominant secondary vectors outdoors. Larval source management should be considered, alongside prevalent indoor-based approaches, amongst a diversification of vector control approaches to more effectively combat residual malaria transmission.

Climate suitability for European ticks: assessing species distribution models against null models and projection under AR5 climate.

BACKGROUND: There is increasing evidence that the geographic distribution of tick species is changing. Whilst correlative Species Distribution Models (SDMs) have been used to predict areas that are potentially suitable for ticks, models have often been assessed without due consideration for spatial patterns in the data that may inflate the influence of predictor variables on species distributions. This study used null models to rigorously evaluate the role of climate and the potential for climate change to affect future climate suitability for eight European tick species, including several important disease vectors. METHODS: We undertook a comparative assessment of the performance of Maxent and Mahalanobis Distance SDMs based on observed data against those of null models based on null species distributions or null climate data. This enabled the identification of species whose distributions demonstrate a significant association with climate variables. Latest generation (AR5) climate projections were subsequently used to project future climate suitability under four Representative Concentration Pathways (RCPs). RESULTS: Seven out of eight tick species exhibited strong climatic signals within their observed distributions. Future projections intimate varying degrees of northward shift in climate suitability for these tick species, with the greatest shifts forecasted under the most extreme RCPs. Despite the high performance measure obtained for the observed model of Hyalomma lusitanicum, it did not perform significantly better than null models; this may result from the effects of non-climatic factors on its distribution. CONCLUSIONS: By comparing observed SDMs with null models, our results allow confidence that we have identified climate signals in tick distributions that are not simply a consequence of spatial patterns in the data. Observed climate-driven SDMs for seven out of eight species performed significantly better than null models, demonstrating the vulnerability of these tick species to the effects of climate change in the future.

Academic Institutions and One Health: Building Capacity for Transdisciplinary Research Approaches to Address Complex Health Issues at the Animal-Human-Ecosystem Interface.

To improve health at the human, animal, and ecosystem interface, defined as One Health, training of researchers must transcend individual disciplines to develop a new process of collaboration. The transdisciplinary research approach integrates frameworks and methodologies beyond academic disciplines and includes involvement of and input from policy makers and members of the community. The authors argue that there should be a significant shift in academic institutions' research capacity to achieve the added value of a transdisciplinary approach for addressing One Health problems. This Perspective is a call to action for academic institutions to provide the foundations for this salient shift. The authors begin by describing the transdisciplinary approach, propose methods for building transdisciplinary research capacity, and highlight three value propositions that support the case. Examples are provided to illustrate how the transdisciplinary approach to research adds value through improved sustainability of impact, increased cost-effectiveness, and enhanced abilities to mitigate potentially harmful unintended consequences. The authors conclude with three key recommendations for academic institutions: (1) a focus on creating enabling environments for One Health and transdisciplinary research, (2) the development of novel funding structures for transdisciplinary research, and (3) training of "transmitters" using real-world-oriented educational programs that break down research silos through collaboration across disciplines.