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Disease X-19 Medical Review

Collection : COVID-19 SARS-CoV-2 preprints from medRxiv and bioRxiv: Two New Models for Epidemics with Application to the COVID-19 Pandemic in the United States, Italy, and the United Kingdom


The Distributed Logistic Model and the Adaptive Logistic Model of epidemics are formulated and used to study the course of cases and deaths during the COVID-19 pandemic. The distributed model is designed to account for a spread of initiation times of hot spots across a country; it does especially well at capturing the initial and linear phases of epidemics. The adaptive model accounts for the development of social mitigation factors, and does especially well at capturing the declining phases of epidemics. The historical data for the U.S., Italy, and the U.K. are analyzed in detail. The parameters of the fits to the two models provide complementary information about the pandemic. The initial infection rate constant was r0 {approx} 0.29 per day for each country, and the effective infection rate constants evolved with time in essentially the same way for each. This suggests that mitigation effects were equally effective in all three countries. Analysis with the distributed model suggests that it took somewhat different times T for the epidemic to spread across each country, with T(US) {approx} 50 days significantly greater than the T’s of Italy or the U.K. The mortality ratio in the U.S. was about 0.061 while in Italy and U.K. it was much larger at about 0.15.

Collection : COVID-19 SARS-CoV-2 preprints from medRxiv and bioRxiv