255 - Using action thresholds to escalate mosquito control interventions

There are a wide range of strategies available for managing mosquito populations and reducing arbovirus transmission. Consistent surveillance data and metrics for human disease risk are critical for escalation of control interventions. In 2023 the Sacramento-Yolo Mosquito and Vector Control District had higher than normal levels of West Nile virus (WNV) transmission throughout their service area. A responsive trapping strategy was utilized to cover all service areas, and enhanced trapping was performed in response to WNV detections. Mosquito collections were tested for WNV, Saint Louis encephalitis and western equine encephalitis. The core surveillance metrics utilized were mosquito abundance, mosquito infection rate, and dead birds that drove further trapping. Vector index was closely monitored and was used to make escalating control interventions. The action thresholds used for control, escalation of mosquito control strategies, impact of control efforts, and the utility of vector index for driving control will be reviewed and discussed.