COVID-19 began spreading across the country early last year. Declared a pandemic in March 2020, public health officials tracked cases, hospitalizations and deaths, but knowledge about COVID-19 prevalence was lacking. To obtain population-based data on current/ past infections, forward-thinking officials at the St. Louis County (Missouri) Department of Public Health contacted epidemiologists at Washington University in St. Louis; they then contacted epidemiologists at the University of Missouri-Columbia with extensive experience conducting population-based surveys. Development/implementation of a population-based survey of adult (≥ 18) county residents who were asked health-related questions and offered free testing for the active virus and/or past infection followed.

Purpose:

Describe how we successfully conducted a population-based survey during the pandemic and obtained prevalence estimates for present and past infection.

Methods:

We developed a COVID-19 module and added it to a modified 2020 Behavioral Risk Factor Surveillance System (BRFSS) questionnaire. This was programmed into a computer-assisted telephone interviewing (CATI) system. Due to COVID social distancing restrictions, we opened a second call center, trained existing interviewers and supervisors and hired/trained additional staff. During the survey (12 Aug-27 Oct 2020), we switched from simple random-digit-dialing (RDD) calls to listed landline and cell samples. Interviewers scheduled tests/ free transportation as needed and sent instructions to respondents. Data were transmitted to Washington University on a nightly basis. Respondents were reimbursed for answering survey questions and being tested (PCR for active virus, antibody test for past infection).

Results:

We interviewed c. 2,300 residents; nearly 1,400 were tested. Individuals testing positive were contacted by phone/ offered assistance. Individuals testing negative were informed in writing.

Conclusions:

Challenges: Short timeframe, COVID requirements. Factors contributing to success: Ability to make rapid procedural shifts (shorten introduction, emphasize reimbursement, call respondents day prior to scheduled test), regular communication (daily data exchange, secure shared folders, daily virtual meetings, weekly team “huddles”) and free transportation to drive-through test sites.