Investigation and public health response to a COVID-19 outbreak in a rural resort community--Blaine County, Idaho, 2020

Blaine County, Idaho, a rural area with a renowned resort, experienced an outbreak of novel coronavirus disease (COVID-19). We undertook an epidemiologic investigation to describe the outbreak and guide public health action. Confirmed cases of COVID-19 were identified from reports of SARS-CoV-2-positive laboratory test results to South Central Public Health District. Information on symptoms, hospitalization, recent travel, healthcare worker status, and close contacts was obtained by medical record review and patient interviews. Viral sequence analysis was conducted on a subset of available specimens. During March 13-April 10, 2020, a total of 451 COVID-19 cases occurred among Blaine County residents (1,959 cases per 100,000 population). An additional 37 cases occurred in out-of-state residents. Among the 451 COVID-19 patients, the median age was 51 years (Interquartile range [IQR]: 37-63), 52 (11.5%) were hospitalized, and 5 (1.1%) died. The median duration between specimen collection and a positive laboratory result was 9 days (IQR: 4-10). Forty-four (9.8%) patients reported recent travel. Healthcare workers comprised 56 (12.4%) cases; 33 of whom worked at the only hospital in the county, leading to a 15-day disruption of hospital services. Of 562 close contacts monitored by public health authorities, 22 (3.9%) had laboratory-confirmed COVID-19 and an additional 29 (5.2%) experienced compatible symptoms. Sequencing results from 34 Idaho specimens supported epidemiologic findings indicating travel as a source of SARS-CoV-2, and identified multiple lineages among hospital workers. Community mitigation strategies included school and resort closure, stay-at-home orders, and restrictions on incoming travelers. COVID-19 outbreaks in rural communities can disrupt health services. Lack of local laboratory capacity led to long turnaround times for COVID-19 test results. Rural communities frequented by tourists should consider implementing restrictions on incoming travelers among other mitigation strategies to reduce COVID-19 transmission.