Covid19 has a R0 of 2.5. Which means, without isolation or protective gear, an infected person can pass the infection to 2.5 persons. With quarantine in place, the R0 drops to practically zero. This accounts for the rapid infection spread within China, and a negligible infection spread outside the containment area.
Not so sure.
Data-Based Analysis, Modelling and Forecasting of the novel Coronavirus (2019-nCoV) outbreak
Our computations and analysis were based on a mean field Susceptible-Infected-Recovered-Dead (SIRD) model. Thus, based on the SIRD simulations, the estimated average value of R0 was found to be 2.5, while the one computed by the official counts of the confirmed cases from the 11th of January until the 18th of January was found to be 4.6. Furthermore, on the estimated parameters from both scenarios, we provide tentative three-week forecasts of the evolution of the outbreak at the epicenter. Our forecasting flashes a note of caution for the presently unfolding outbreak in China. Based on the official counts for confirmed cases, the cumulative number of infected will surpass 68,000 (as a lower bound) and could reach 140,000 (with an upper bound of 290,000) by February 29. Regarding the number of deaths, simulations forecast that on the basis of current data and estimations on the official count of infected people in the population, the death toll might exceed 7,000 by February 29;.....
These 2 questions will determine if the coronavirus becomes a deadly pandemic
If one narrows the estimates to some of the world’s top epidemiological modeling labs — like
Maia Majumder’s at Boston Children’s Hospital or
Christian Althaus’s at the University of Bern or
Jon Read’s at Lancaster or
China CDC’s — the range looks a little broader: 2 to
3.11. That would make the new coronavirus more contagious than seasonal flu and potentially even more contagious than SARS.
Early basic reproduction number estimates for
#nCoV2019 range from 2.0 to 3.3 (based off of publicly reported confirmed cases through 1/22/20 & subject to change) [
http://ssrn.com/abstract=3524675]. Short explainer & several caveats in the thread below.
For R0 greater than one the number infected is likely to increase, and for R0 less than one transmission is likely to die out.
The basic reproduction number is a central concept in infectious disease epidemiology, indicating the risk of an infectious agent with respect to epidemic spread.
The WHO
estimates that the COVID-19 coronavirus has an R0 of between 1.4 and 2.5.
“Our review shows that the coronavirus is at least as transmissible as the SARS virus,” said
Professor Joacim Rocklöv, a researcher at Umeå University, Sweden.
“And that says a great deal about the seriousness of the situation.”
Professor Rocklöv and colleagues identified 12 recent studies which estimated the basic reproductive number for COVID-19 from China and overseas.
“The studies consisted of estimations of the growth rate based upon the cases observed in the Chinese population, and based upon statistical and mathematical methods,” they said.
“The earliest studies of the coronavirus indicated a relatively low transmissibility.”
“Thereafter, the transmissibility rose rapidly to stabilize between 2-3 in the most recent studies.”
The reproduction number in the studies summed up to a mean of 3.28, and a median of 2.79, which is significantly higher than WHO’s estimate of 1.4-2.5.
“When looking at the development of the COVID-19 epidemic, reality seems to correspond well to or even exceed the highest epidemic growth in our calculations,” Professor Rocklöv said.
“Despite all intervention and control activities, the coronavirus has already spread to a significantly higher extent than SARS did.”
The stated estimates are all over the place, primarily because the Chicoms are not cooperating in getting valid data out to the public and the world medical community.
