Methods and Data

All data is imported from the official Merced County Department of Public Health website. Archives of official press releases can be found here. Press releases were initially issued daily. The frequency was reduced to five times a week on May 8 and to once a week on June 12 (Wednesdays). Starting June 15, numbers of total cases, recovered patients, and deaths were copied manually from the Merced County COVID-19 Statistics dashboard on all days except Wednesdays. We are not aware of an an official archive of the dashboard data.

• Merced county population (Jan 2020 estimate)= 287,420

• When the frequency of press releases was reduced to less than once a day the gap in dily increase was filled by linear interpolation; i.e., the number of cases reported in the intervenning period was divided by the number of gap days and applied equally to all days.

• Active cases was calculated by subtracting number of recovered patients and deaths from the total confirmed cases. The number of deaths and active cases was removed from the dashboard as of June 30

• 14-Day Increase per 100,000 was calculated as

100,000 * {(New today) - (New two weeks ago)}/ {Population}

• 7-Day positivity was calculated as:

100 * {(New today) - (New last week)}/ {(Total today)-(Pending today) - (Total last week)-(Pending last week)}

• Rate of daily increase (e.g., current rate is 5.5% per day) can be used to estimate the number of days for doubling cases:

70/Rate_of_increase