HKU Medicine has released new nowcasting and forecasting estimates for the 2019-nCoV outbreak. They estimate that the current R0 is between 1.9 and 2.3, and that current case counts may be in the range of 20,000 to 78,000.
Even with the lower transmission rate, there need to be draconian quarantine efforts. We are at the point where China has to use all community-level measures to increase social distance and more community-wide quarantines.
R0 transmission must be reduced to less than 1.0 to stop the spread of the disease.
There is other UK and US research which estimates the basic reproduction number of the infection (𝑅0) to be between 3.6 and 4.0. Novel coronavirus 2019-nCoV: early estimation of epidemiological parameters and epidemic predictions
Jonathan M. Read, Jessica R.E. Bridgen, Derek A.T. Cummings, Antonia Ho
, Chris P. Jewell.
If the R0 is 3.6 to 4.0 then 72-75% of transmissions must be prevented by control measures for infections to stop increasing.
The spreading rate is between the flu and SARS.
They estimate that only 5.1% of infections in Wuhan are identified, indicating a large number of infections in the community, and also reflecting the difficulty in detecting cases of this new disease. Surveillance for this novel pathogen has been launched very quickly by public health authorities in China, allowing for rapid assessment of the speed of increase of cases in Wuhan and other areas.
If no change in control or transmission happens, then we expect further outbreaks to occur in other Chinese cities, and that infections will continue to be exported to international destinations at an increasing rate. The model suggests that by 4 February 2020 the number of infected people in Wuhan will be greater than 190
thousand (prediction interval, 132,751 to 273,649). They predict the cities with the largest outbreaks elsewhere in China to be Shanghai, Beijing, Guangzhou, Chongqing and Chengdu. We also predict that by 4 Feb 2020, the countries or special administrative regions at greatest risk of importing infections through air travel
are Thailand, Japan, Taiwan, Hong Kong, and South Korea.
If the official number of cases is below 10,000 in eight days then the R0 estimate of 3.6 to 4.0 would be higher than the actual situation. However, higher cases would not confirm a higher transmission rate. The percentage of identified cases could increase from 5%.
The UK-US model suggests that travel restrictions from and to Wuhan city are unlikely to be effective in halting transmission across China; with a 99% effective reduction in travel, the size of the epidemic outside of Wuhan may only be reduced by 24.9% on 4 February.
Reducing the spread by 25% is still useful.
So far the deaths from coronavirus is mostly older men with previous health issues. The youngest person to die in the first 17 was a 48-year-old woman. As of today’s morning report there are now 82 deaths.
Beijing has broadened the extraordinary quarantine to more than 50 million people, but the mayor of Wuhan, the outbreak’s epicenter, said 5 million people had already left his city.
Wuhan’s mayor admitted that the city did not release information about the virus in a timely manner but hinted that it was prevented from doing so by central authorities.
A scientific assessment of the spread of the disease, assuming an optimistic 90 percent quarantine, still predicted more than 59,000 infections and 1,500 deaths — twice the toll of the 2002-2003 SARS outbreak.
A John’s Hopkins simulation led by Eric Toner published 3 months ago indicates that an uncontained pandemic disease over a span of 18 months would have deaths in the range of 65 million. A global pandemic could cause an average annual economic loss of 0.7% of global GDP — or $570 billion. They indicated that their model was not matched up to this actual disease outbreak.
The Bill and Melinda Gates Foundation announced $10M in awards to fight the epidemic. Half is to go to China and half to Africa. Reuters has reported that the Chinese government is dedicating almost US$9 billion toward efforts to quell the spread of the outbreak. However, News China has reported totals closer to US$1.5 billion.
The World Health Organization has not declared a Public Health Emergency of International Concern (PHEIC). A PHEIC is a formal declaration by the World Health Organization of “an extraordinary event which is determined to constitute a public health risk”.
Amplification has occurred in one health care facility. Of confirmed cases, 25% are reported to be severe. The source is still unknown (most likely an animal reservoir) and the extent of human-to-human transmission is still not clear.