Syndromic Surveillance Tracks COVID-19 Cases in University and County Settings: Retrospective Observational Study

Area of Science:

• Public Health
• Epidemiology
• Infectious Disease Surveillance

Background:

• Syndromic surveillance offers a cost-effective complement to traditional test-based COVID-19 surveillance.
• Monitoring COVID-19-like illness (CLI) can facilitate timely interventions to prevent outbreaks without solely relying on testing.

Purpose of the Study:

• To evaluate the temporal relationship between confirmed SARS-CoV-2 infections and reported CLI.
• To assess the utility of syndromic surveillance in both university and county settings.

Main Methods:

• Utilized aggregated COVID-19 testing and symptom data from a university (2020-2021) and county health department (2020-2022).
• Employed negative binomial and linear regression models to correlate CLI rates with COVID-19 test positivity and case counts.
• Identified optimal lag periods using Granger causality and likelihood ratio tests.

Main Results:

• On a university campus, CLI rates correlated with COVID-19 test positivity with no lag.
• At the county level, health care provider-reported CLI was a leading indicator, correlating with SARS-CoV-2 test positivity with a 3-day lag.

Conclusions:

• Syndromic surveillance, particularly symptom reporting, is a viable supplement to COVID-19 testing for real-time monitoring.
• County-level syndromic surveillance serves as a leading indicator, enabling prompt public health action.
• Further research is recommended for syndromic surveillance in diverse settings, including low-resource countries.