Covid Epidemiology Data Dallas County Trends
New Cases
Existing Total of Active Cases
(Ro) or 'R naught' value
Basic replication rate (Ro) or 'R naught' expresses the overall virulence of an infectious agent in a specific location/population. This number is comparatively calculated with the number of new cases versus the number of existing infections. If the Ro is >1, an infectious agent is likely to cause significant outbreak or epidemic within a community or location. If Ro is less <1, significant outbreak is less likely. World wide, SARS-COV-2 has an established Ro of 2-3, which can be mitigated by social distancing measures.
Rt value
Effective replicaiton rate (Rt) expresses the number of secondary infections that are likely to occur from a single infection in a specific area. This number takes into account location size, local enforcement of social distancing, and 'social mobility' variables. If Rt is >1 or trending up, significant community spread of an infectious agent is occuring. If Rt is <1 or trending down, community spread is less probable or decreasing.