Epidemics begin in one of three model independent ways.
- Exponential (Incidence accelerates rapidly)
- 1918 Influenza (San Francisco, 1918)
- Plague (Bombay, 1905)
- Smallpox (Khuina, Iran, 1977)
- Power (Incidence increases day by day)
- Measles (London, 1948)
- HIV/AIDS (New York City, 1982 – 2002)
- Linear (Incidence remains constant)
- Heart Disease
COVID-19 in Mississippi has grown persistently.
Cases and deaths have both grown quadratically since March 13, 2020. (Data are the daily reports given by MSDH.)
Deaths lagged by 5 days - the latency between COVID-19's first symptoms and death.
The Stay-in-Place proclamation(yellow marker) and its reverse (green marker) had little apparent effect on these overall trends.
Two distinct COVID-19 epidemics have existed side-by-side: Community and LTC Facility Residents'.
Deaths in the community have grown linearly with time. LTCF deaths have accelerated at a much faster rate after a short delay.
(Red dots plot the Community COVID-19 deaths, according to the date on the death certificate; the brown are the LTCF Resident deaths. The most recent data points are incomplete counts - the recording of death certificates takes a little time. )
The cumulative number of COVID-19 deaths grew exponentially for the first few days, just as in New York City.
The importance of this growth cannot be understated. This initial growth points to 24 deaths a day on April 1 and 9,670 deaths a day on May 1.
After Shelter-in-Place was established, growth became linear (left graph). Initially the rate averaged more than 5 a day, and trended slightly downward (right graph). Since restrictions have been relaxed (green dots), the numbers have tended slightly upward.
The number of COVID-19 Death Certificates issued daily grew linearly up to Shelter-in-Place. If continued at this rate, ~30 deaths would be now be recorded each day.
- the last two or three days of data are incomplete
- it does take time to register the deaths
- so these small numbers are only a distraction.
Deaths of residents of Long Term Care Facilities now exceed half the Mississippi COVID-19 deaths.
The first LTCF death was March 21, 2020. Deaths grew as a cubic function of time, and so have caught up - and surpassed - the number of community deaths.
The daily log of LTCF deaths (per death certificates) grows linearly. The smaller numbers in the last few days reflect the lag in registering death certificates.