COVID Incidence Maps

We create incidence maps based on reported lab confirmed cases in the last week, as well as for the last two weeks (for each Zip Code and School District). We calculate incidence rates by dividing the raw case counts by the population of each region and multiplying by 1,000 (which produces a cases per 1,000 people rate). These maps provide a more reasonable characterization of a person’s recent risk of coming into contact with an infectious person than a map of cumulative cases or case rates (which may include cases from months ago).

COVID Incidence Trend Maps

We createincidence trend maps base on changes in reported COVID-19 cases in the past two weeks. We assign each region into one of four categories: declining (trend in daily cases is falling by at least one case per week), no discernible trend, increasing moderately (trend in daily cases increasing at least one case per week), increasing rapidly (trend in daily cases increasing by at least three cases per week). This map shows regions where we believe SARS-CoV-2 transmission is changing and is not intended to be interpreted as a “risk” map.1

  1. For example, a Zip Code with a gradual increase in daily cases from 2 to 10 in the past two weeks would be categorized the same as a Zip Code with a gradual increase in daily cases from 12 to 22.↩︎

For questions, email us at nc-covid@unc.edu