Case studies and reports
- Paper: Characterizing the spread of CoViD-19, D. Karlen, July 13, 2020.
- introduces the pypm framework and describes methods to define comparitive statistics with weak model dependence and estimate their uncertainties
Click on the titles below to see detailed results from the studies.
February 28, 2021: 16 German states
This study was prepared for inclusion in the German forecast-hub, led by researchers at the Karlsruhe Institute of Technology and the Heidelberg Institute for Theoretical Studies.
Data is provided by Robert Koch Institut Unlike the situation in the US, immunity is not playing a significant role in bringing down the infection.
Recently cases are starting to increase and there is concern about B.1.1.7 variant. The model fits include a second infection cycle for the variant with a nominal advantage of 10% per day larger growth rate. Model fits to the case data appear to be consistent with variant fraction currently making up about 30-40% of cases.
February 23, 2021: BC by health region
The BC government makes available the number of cases each day, divided into sex, age, and health region. The data differs somewhat from that used in the Canada-wide studies, possibly due to corrections in the dates assigned to each positive case.
In October the province saw COVID-19 growth in all regions with the strongest growth in the two Vancouver health regons. At the beginning of November, new restrictions came into force in Vancouver, which reduced the rate of growth.
The Fraser Health region had see declining daily cases, since mid-November, unlike the other regions which had steady or growing case numbers. Starting at the end of January, cases started growing again in the Fraser HA, at about 2 +/- 1 % per day.
The growth in Vancouver Island has stopped, and there is now significant decline in the Interior. The Coastal and Northern regions remain steady.
Forecasts for the next 4 weeks are provided. Comparisons of observations and a forecast from last month are shown.
February 21, 2021: USA by state
This is the latest analysis prepared for the COVID-19 Forecast Hub, in coordination with the US CDC.
Overall the US forecasts show decline. Vaccination is well underway. Plots for each state show how natural and vaccination immunity is playing a role to bring infections down.
Click on the above image to see a time lapse animation of how COVID-19 spread through the USA. The colors indicate the fraction of the population in each state who are contagious. The scale is logrithmic: a difference of 1 unit corresponds to a factor of 10 in the contagious fraction. The above still image is the snapshot for November 15.
February 7, 2021: 9 provinces
This is an update of the previous Canadian provincial analyses, now using data from March 1, 2020 - February 6, 2021. The report includes forecasts for the upcoming 4 weeks.
February 5, 2021: Israel during vaccine deployment
Israel currently has the highest rate of vaccinations per capita, with more than 40% of the population having received their first dose by early February. The case and vaccination time-series data from Israel are analyzed and amongst the older population, being nearly 90% vaccinated, the decline in cases is consistent with expectations from vaccination immunity.
This represents the first quantitative demonstration of the herd-effect to COVID-19 at a national scale.
November 22, 2020: USA by state
This is a analysis that uses data on hospitalizations recently made available by the US HHS. Prior to this analysis, hospitalization data from the Covid Tracking Project has been used.
October 5, 2020: California by age
California provides daily case, hospitalization, and death data by age group. This provides useful data to study how to model a non-homogenous population.
June 24, 2020: Brazil states
An initial study of Brazil data: fitting to death data only.