COVID-19, San Antonio, July 7, 2020

This report contains analyses based on data transmitted on Sunday, July 5, by San Antonio Metro Health Department (SAMHD) and the South Texas Regional Advisory Council (STRAC) to the University of Texas at San Antonio. This report supersedes previous reports.

• This model presents projections using data reliably measured up to June 26, 2020. These projections will evolve as the situation on the ground evolves. The current lag between modeling and data is eight days for SAMHD and zero days for STRAC.
  
• The effect of the second declaration of emergency in San Antonio on June 17 will be measurable when the number of cases per day has been consolidated up to June 30. See commentary below about consolidation of cases per day. The preliminary results seem encouraging; however, there could be delays in reporting/processing from labs given the surge in cases.
  
• The effect of Governor Abbott’s order to wear facemasks in public will be measurable whenever we have consolidated records for July 16. This could happen toward the end of July.
• There could be 34,000 +/- 5,000 new community transmission cases in the next three weeks. Another 29,000 +/- 6,000 one week later. This is due to exponential growth in the number of community cases at a rate of exponential growth of approximately 7% daily.
  
• The total number of cases accumulated by the end of summer could be very large (104,000 +/- 35,000).
  

About Consolidation of Past Records

When a number of cases is reported for a single day, the records are actually distributed in past days. The figure below shows how the final number of cases attributed to a single day increase as time progresses. The bottom line shows the number of cases for each day as reported on June 30. The top line shows the number of reported cases for the same days, but according to the data transmitted on July 5. Every day increased the number of cases. Therefore, caution must be exercised before assuming that a declining trend is indeed a sign of less community transmission; it could be delay in reporting/processing of lab results.

This is a project of the Biomathematics Research Group