The positivity rate—also referred to as “percent positive rate” or “percent positive” is the percentage of all coronavirus tests performed that are actually positive. Positivity rate is usually expressed as a percentage. It is an indicator of whether enough testing is occurring if enough asymptomatic and mild cases are being tested.
Prevalence, on the other hand, is a specific number of people who have (or had) COVID-19 during a specific time period. This would be the number of truly positive individuals out of the entire population—not just those who is tested. Prevalence can help researchers and decision-makers understand the larger picture of COVID-19 spread in a specific area or population.