Wildfires are an integral part of many ecosystems; however, in recent years, human behavior and climate change have resulted in wildfire seasons that are longer, more destructive, and more costly. During wildfire events, public health responses most often focus on the health effects of wildfire smoke-related air pollution (i.e., exposure to fine particulate matter [PM2.5]), including exacerbations of respiratory and cardiovascular disease.
Due to the near real-time nature of syndromic surveillance, it can be an effective public health tool for responding to environmental threats like wildfires. However, no standard national syndrome definitions currently exist to enumerate wildfire-related healthcare visits. To strengthen the public health community’s ability to track health outcomes of wildfire events, the Council of State and Territorial Epidemiologists (CSTE) Climate, Health, and Equity Subcommittee, in collaboration with the Centers for Disease Control and Prevention’s (CDC) Asthma and Community Health Branch, convened a workgroup of local, state, and federal syndromic surveillance practitioners and public health preparedness and environmental epidemiologists to collect and review existing wildfire-related syndrome definitions, develop novel definitions, and disseminate guidance.
Through the collection and review of state and local syndrome definitions, the workgroup developed two novel syndromes in hopes of nationally standardizing syndromic surveillance of wildfire-related visits: Fire and Smoke Inhalation v1 (formerly wildfire and smoke visits during project period) and Air Quality-related Respiratory Illness v1 (formerly respiratory visits of interest during project period). Workgroup members from four jurisdictions validated these definitions by using an a priori stepwise approach. Validation centered on known wildfire events, but validators also included pre-and post-fire periods in determining trends. Each validator selected a time period and geography that was appropriate for their data system and local conditions. Daily (i.e., 24-hour) average PM2.5 was used as an air pollution validation metric, and correlation between the novel syndrome definitions and daily average PM2.5 was assessed.
Overall, the Fire and Smoke Inhalation v1 syndrome definition alerted during known wildfire events, aligned well with daily average PM2.5, showed elevated visits among adults (>18), and most reviewed visits were categorized into respiratory, injury, and other wildfire-related syndromes. The Air Quality-related Respiratory Illness v1 syndrome definition is broad and thus, did not always correlate with PM2.5; however, results improved when the definition was combined with more specific respiratory illness syndrome definitions or the fire and smoke inhalation syndrome definition.
In addition to the novel syndrome definitions, this guide includes case studies illustrating how jurisdictions use wildfire-related syndrome definitions, report on wildfire events, and distinguish smoke-related respiratory visits from pandemic-related respiratory visits during concurrent disasters. The guide also includes options to customize definitions for jurisdictional use, ways to use air pollution monitor data effectively, and best practices for related public health action and trend analysis.
The final report can be accessed here.