The Effect of Urbanization and Climate Change on Mosquito Population in the Pearl River Delta Region

Background: The rising incidence of mosquito-borne diseases is a global concern. Changes in regional climate may affect the ecology of mosquitoes and mosquito transmitted pathogens. The effects of changes in climate on mosquito population dynamics are complex but critical and urgent for implementing more effective public health policy. This study quantified the impact of urbanization and global climate change on the population of the mosquito species, Culex quinquefasciatus, in the Pearl River Delta region in southern China - an area that has undergone substantial urbanization and is expected to experience changes in climate. Methods: This study employed a mechanistic model to simulate mosquito population dynamics under various greenhouse gas emission and land-cover change scenarios based on climate data provided by a state-of-the-science regional climate model. Findings: Our results show a 12·6% decrease in annual mosquito population in newly urbanized (N/U) areas and a 5·9% increase in annual mosquito population in existing urban (U/U) areas. Furthermore, changing climate conditions were projected to cause a 15-17% reduction in the total annual mosquito population, however, the change will not be uniform throughout the year. Peak months exhibit a reduction in population, whereas non-peak months show a significant increase. Interpretation: These findings suggest mosquito control strategies may need to be adjusted to respond to the impacts of urbanization and climate change on mosquito population dynamics to maximize effectiveness. Region specific, quantitative analyses of environmental impacts on mosquito-borne disease ecology, like this study, are needed to provide policy makers with a scientific reference to guide the formation of effective transmission intervention strategies. Funding: This work is jointly funded by the Improvement on Competitiveness in Hiring New Faculties Fund (2013/14) of The Chinese University of Hong Kong and the Vice-Chancellor's Discretionary Fund of The Chinese University of Hong Kong (grant no. 4930744). Declaration of interests: We declare no competing interests.