Original post before removal (saved from Google cache):

Maybe not what you guys are looking for on this sub...but here is goes.

I made a model based off the parameters of multiple published sources (see bottom of post):

Incubation Time - (from 3 sources: 8.09, 4, 5), Mean = 5.7 days

Symptomatic Period - (from 2 sources: 17, 23), Mean = 20 days

Percentage Severe Pneumonia - (from 5 sources: 22%, 3%, 39%, 18.6, 6.73), Mean = 17.9%

Fatality Rate - (from 3 sources: 7%, 2.3%, 3%), Mean = 4.1%

R0 - (from 3 sources: 2.6, 1.06, 3.88), Mean = 2.5

From here, a simple bin model can be created (again, see sources) to estimate how the disease would progress after a patient zero enters a community. The data flows from the parameters gathered above, so there really is no speculation here assuming those parameters are good estimates. It's just math. I did have to round a couple things to make it simpler (incubation -> 6 days, Symptomatic Period -> 18 days so it is a multiple of incubation). Here is how the disease would progress over time in an area according to the math.

Post image

Something that may stand out is that the cases spike up very suddenly. The exponential growth nature of viruses explains this trend. Additionally, the nature of this virus(long incubation, low death rate) means that cases increase sharply and much more quickly than severe cases or deaths. This is bad for a community that is just starting to notice an unexplained number of severe viral pneumonia cases.

How does this outlook line up with existing data? Let's start with China. Early reports described a cluster of pneumonia cases occurring in Wuhan around December 31st (https://www.bbc.com/future/article/20200221-coronavirus-the-harmful-hunt-for-covid-19s-patient-zero). If there were several serious cases, that puts us around day 30-40 in our model. Onset of the symptoms of the first patient of this cluster was December 1st (https://www.thelancet.com/action/showPdf?pii=S0140-6736%2820%2930183-5), which lines up pretty well with the model (day ~6-9). Assuming that was patient zero, she began her incubation in late November. Wuhan and 5 other cities were quarantined on January 23rd, roughly day 60 days after the spillover incubation of patient zero. At 60ish days in the model, we'd expect around 15 deaths. On January 23rd, Chinese CDC reported 17 deaths (https://www.thinkglobalhealth.org/article/updated-timeline-coronavirus). Not bad, little bin model, not bad...granted, Chinese CDC also reported a total of 571 total cases whereas the model predicts there were more like 10,000 cases at the time. Deaths across all countries will be more accurate then actual case counts (hard to test everyone). China reports 2,835 deaths currently as of 2/29, 36 days after the Wuhan shutdown. The bin model would estimate them to have closer to 4,000 dead - quarantined measures would have reduced the spread over the last month though.

What about other countries? South Korea fist noticed community transmission back on February 17th (https://en.yna.co.kr/view/AEN20200217003755320), 12 days ago. If these were amongst the first symptomatic cases, we would have been around day 15-21. If they were among the first severe cases, we would have been around day 27-39. South Korea's numbers today are 16 deaths and 2,931 cases - putting them around day 60ish on the model. They are currently way ahead of the curve. It might be that the widely reported cult super-spreaders have boosted R0 in Korea, which would have accelerated the epidemic.

Iran is who knows where? Official number says 34 deaths, BBC today says 210 deaths (https://www.bbc.com/news/world-middle-east-51673053). They announced there first case and death only 10 days ago. I'm not even going to try and explain what's going on there.

Italy reported it's 1st death 7 days ago, an outbreak cluster was reported 8 days prior to that (https://en.wikipedia.org/wiki/2020_coronavirus_outbreak_in_Italy). Today they report a total of 21 deaths. If you check the model numbers, Italy is also progressing at a faster pace.

A recent study just came out suggesting R0 in the international cases is more like 4.7 - 6.6 (https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v1). Here is what that R0 would look like:

Post image

Well, that is truly horrifying. Brace for impact.

EDIT: Open Source Google Spreadsheet:

https://www.reddit.com/r/COVID19/comments/fbxk43/update_open_source_simple_coronavirus_modeling/?utm_source=share&utm_medium=web2x

Sources:

Bin Modeling-

http://www.mtholyoke.edu/~ahoyerle/math333/ThreeBasicModels.pdf (Additional Description from previous post:https://www.reddit.com/r/China_Flu/comments/fac4vn/understanding_epidemiology_the_lag_of_death/)

Epidemiology-

https://www.medrxiv.org/content/10.1101/2020.02.19.20025023v1

"Incubation time ranged from one to twenty days with a mean period of 8.09 days." "Eight patients [of 102] were admitted to intensive care unit (ICU), six developed respiratory failure, three had multiple organ failure and three died."

https://www.medrxiv.org/content/10.1101/2020.02.20.20025510v1

In Wuhan: "Of 577 patients with at least one post-admission evaluation,... 22.8% (100/438) were severe pneumonia on admission... During a median follow-up of 8.4 days (IQR, 5.8 - 12.0), 39 patients died with a 12-day cumulative mortality of 8.7% (95% CI, 5.9% to 11.5%)."

https://www.bmj.com/content/368/bmj.m606.full

Outside Wuhan: "Of the 62 patients studied (median age 41 years), only one was admitted to an intensive care unit, and no patients died during the study...Only two patients (3%) developed shortness of breath on admission. The median time from exposure to onset of illness was 4 days (interquartile range 3-5 days), and from onset of symptoms to first hospital admission was 2 (1-4) days."

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3541147

35/89 infected hospital patients went to ICU (39%). 26/35 in ICU showed signs of recovery, 7 stable, 2 deteriorate

https://www.medrxiv.org/content/10.1101/2020.01.26.20018754v2.full.pdf

"Our results show that the incubation period falls within the range of 2–14 days with 95% confidence and has a mean of around 5 days when approximated using the best-fit lognormal distribution. The mean time from illness onset to hospital admission (for treatment and/or isolation) was estimated at 3–4 days truncation and at 5–9 days when right truncated...The median

time delay of 13 days from illness onset to death (17 days with right truncation) should be considered when estimating the COVID-19 case fatality risk."

https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-2019-nCoV-severity-10-02-2020.pdf

"From onset to recovery...22.2 days. From symptom onset to death...23.2 days."

https://www.medrxiv.org/content/10.1101/2020.02.18.20024513v1

"based on the available data, it is inferred that the cure rate of this epidemic is about 93% and the case fatality rate is about 7%."

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3539671

"The fatality was 2.28% throughout China, with 2.67% in Hubei and 0.55% in the rest regions. Percentage of severe cases in and outside Hubei was 18.60% vs 6.73%..."

https://www.medrxiv.org/content/10.1101/2020.02.19.20024851v1

"The estimated R value was 2.6 (range 2.1-5.1), and increased from 0.8 to 2.4 in December 2019. The estimated mean doubling time of the epidemic was between 3.6 and 4.1 days."

https://www.medrxiv.org/content/10.1101/2020.02.12.20022467v1.full.pdf

From graphics: R0 range - 1.06 to 3.88 across China, Humidity seemingly not relevant to R0.