BACKGROUNDIn the Netherlands, locally acquired animal and human cases of West Nile virus (WNV) were first identified in 2020 via multidisciplinary WNV monitoring and research activities focusing on mosquitoes, birds, horses, and humans.AIMWe investigated how different activities contributed to WNV detection and response in the Netherlands between 2020 and 2023, to determine best practices, challenges, and opportunities for improvement.METHODSWe identified WNV monitoring and research activities in the Netherlands from 2020 to 2023 and analysed their timeliness to detect and react to WNV circulation. An after-action review (AAR) was conducted with national WNV experts to assess best practices and challenges in the multidisciplinary approach.RESULTSIn 2020, WNV circulation was discovered in an infected bird through a wild live bird research survey and subsequently through mosquito research and monitoring. Thirty-five days after finding the WNV-PCR-positive bird, the first autochthonous human case was uncovered. Between 2021 and 2023, research projects in animals, including sentinel chickens, detected ongoing local enzootic WNV circulation. The AAR highlighted rapid information sharing and interpretation, enabled by multidisciplinary collaborations, as best practice. However, differing institute priorities could sometimes lead to diverging views on follow-up actions.CONCLUSIONResearch and monitoring activities in mosquitoes and animals, particularly wild birds and sentinel chickens, enabled early detection of WNV circulation. Real-time testing could provide early warning of human cases, enabling timely responses. Therefore, these research and monitoring activities should be maintained. Multidisciplinary collaboration enabled rapid detection and response, and addressing remaining challenges could further strengthen effectiveness.
Best et al. (Thu,) studied this question.