The Regional Viral Respiratory Surveillance Data Dashboard is used to show the burden of respiratory illness in the communities of Chelan, Douglas and Okanogan counties. The data displays local and regional trends in respiratory illness, including Acute Respiratory Illness (ARI), COVID-19, influenza, and respiratory syncytial virus (RSV).
Healthcare Visit Data
The healthcare visits data represents percentages of emergency department (ED) visits and inpatient hospitalizations among patients receiving care at healthcare facilities in Chelan, Douglas, and Okanogan counties. Data for Chelan and Douglas counties are combined, as emergency healthcare services are in Chelan County and serve residents from both counties. Regional data represent Chelan, Douglas and Okanogan counties combined, and residents from neighboring counties may also seek care at these facilities.
Weekly Data
The data is displayed by MMWR week, which is the standard reporting week used by local, state and federal public health agencies to track and report disease incidence. Each week begins on Sunday and ends the following Saturday. The respiratory illness surveillance season begins on MMWR Week 40 (early October) and continues through MMWR week 39 (late September) of the following year. A list of the MMWR weeks for the 2026-27 respiratory illness season may be found here.
The dashboard data will be updated every Thursday by 5 pm during peak respiratory season (mid-October through late May of the following year). Thanksgiving week the data will be updated the following week on Thursday, December 3rd.
To view additional local and state data on illness trends, please visit the WDOH Respiratory Illness Data dashboard.
About the Data
Data are sourced from the Washington Department of Health (WDOH) Rapid Health Information Network (RHINO) through the National Syndromic Surveillance Program (NSSP) BioSense ESSENCE platform, a Centers for Disease Control and Prevention (CDC) system used for near real-time monitoring of health trends.
The data represents patient ICD-10 discharge diagnosis codes associated with Acute Respiratory Illness (ARI), COVID-19, influenza, and RSV. The ARI metric includes ED visits with patient ICD-10 codes that include a broad range of acute respiratory illness diagnoses, including specific pathogens (e.g., influenza, RSV, SARS-CoV-2), pneumonia (viral, bacterial, or unspecified), bronchitis, upper respiratory infections, respiratory failure, and other acute respiratory syndromes. More information about the diagnoses included in this metric may be found here. COVID-19, influenza, and RSV data represent ED visits and hospitalizations with patient ICD-10 codes that include a diagnosis of the specific respective pathogen. These diagnoses may or may not be accompanied by a confirmed laboratory test.
Disease Activity Thresholds and Infection Prevention Measures
Disease Activity thresholds are used to identify when respiratory illness activity is considered elevated in the community. Chelan-Douglas Health District uses regional thresholds based on data from counties in the North Central Washington region. The thresholds are applied to respiratory illness visits in weekly emergency departments to determine when the activity is considered elevated. The threshold values listed below represent the percentage of weekly ED visits for each condition and pathogen:
Acute Respiratory Illness (ARI): 14.5%
COVID-19: 1.1%
Influenza: 1.5%
RSV: 0.5%
When one or more thresholds are exceeded, Chelan-Douglas Health District encourages health care facilities and providers to use heightened preventive measures for respiratory infection, as referenced in this season’s letter from Regional Health Officers. This may include masking in patient care areas, encouraging masking for all patients and visitors, and expediting rooming or isolation for patients with respiratory symptoms. Heightened preventive measures are recommended until ED visits for ARI and all pathogens (COVID-19, influenza and RSV) fall below their respective disease activity thresholds for two consecutive weeks.