Are we doing our best to contain the spread of West Nile virus? Evaluating intervention efficacy through mathematical modelling

Background: West Nile virus (WNV) is an emerging vector-borne pathogen that is becoming increasingly prevalent in temperate regions. The development of effective intervention strategies is crucial for limiting its spread; however, the adaptability and ubiquity of mosquitoes, combined with the complexity of the WNV transmission cycle, continue to hinder its eradication. Methods: This study employs a deterministic compartmental model to evaluate the effectiveness of ten intervention strategies targeting either the mosquito (vector) or avian (host) population in the Lombardy region of Italy. Results: Vector-targeted interventions were more effective than host-targeted measures, with breeding site reduction and larvicide treatments demonstrating the greatest efficacy. In contrast, interventions targeting adult mosquitoes, including adulticide treatments and elimination of overwintering mosquitoes, showed moderate efficacy. Furthermore, the impact of eliminating overwintering mosquitoes gradually diminished over time. Host-targeted strategies, such as bird population reduction, were ineffective and, in some cases, led to increased WNV transmission. The efficacy of all interventions varied temporally, peaking in mid-summer. Conclusions: These findings highlight the importance of prioritising mosquito control, particularly targeting immature stages, to mitigate WNV outbreaks. Our study highlights the critical role of mathematical modelling in designing effective intervention strategies. By providing a structured framework to evaluate and predict the outcomes of various approaches, modelling can aid disease control while optimising resource allocation and minimising environmental impact. Mathematical models, therefore, prove to be powerful tools for balancing public health goals with sustainable practices.