Covid Epidemiology Trends: Data Dallas County

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  • 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.