Chinese Mystery Disease Update No 5: WORLD IN PANIC! 440 confirmed cases equal almost 20,000, unconfirmed cases according to Prof Neil Ferguson's table: MRC Centre for Global Infectious Disease Analysis

A staff member checks passengers' body temperature at Hankou Railway Station in Wuhan, capital of central China's Hubei Province, Jan. 22, 2020. Chinese health authorities announced Wednesday that 440 confirmed cases of pneumonia caused by the novel coronavirus (2019-nCoV) had been reported in 13 provincial-level regions in the country by the end of Tuesday. Strict measures have been taken to prevent the spread of the virus. A total of 15 thermal detectors have been set up in the Wuhan Tianhe International Airport, and 20 thermal detectors have been installed in three major railway stations of the city. (Xinhua/Xiao Yijiu)

Chinese health authorities announced Wednesday that 440 confirmed cases of pneumonia caused by the novel coronavirus (2019-nCoV) had been reported in 13 provincial-level regions in the country by the end of Tuesday. According to Prof Neil Ferguson's table, (see below) of the MRC Centre for Global Infectious Disease Analysis at Imperial College London, 440 confirmed cases is the equivalent of almost 20,000 unconfirmed cases.

 The cases had resulted in nine deaths, all in central China's Hubei Province, said Li Bin, deputy director of the National Health Commission, at a press conference. Altogether 149 new confirmed cases were reported Tuesday, Li added. Overseas, one case has been confirmed in Japan, three in Thailand, and one in the Republic of Korea. A total of 2,197 close contacts have been traced, figures from the commission show. Among them, 1,394 are under medical observation while 765 others have been discharged.

Meanwhile, hundreds of millions of Chinese are on the MOVE, celebrating their Spring Holiday, new year festivities.

Published 5 days ago 45 confirmed cases was the equivalent of up to 2,000 cases, Today, 440 confirmed cases, is, therefore, the equivalent of almost 20,000 unconfirmed cases according to Prof Neil Ferguson

According to Prof Neil Ferguson's table, (see below) of the MRC Centre for Global Infectious Disease Analysis at Imperial College London, 440 confirmed cases is the equivalent of almost 20,000 unconfirmed cases.
The number of people already infected by the mystery virus emerging in China is far greater than official figures suggest, scientists have told the BBC. There have been 45 laboratory-confirmed cases of the new virus, but UK experts estimate the figure is closer to 1,700. Two people are known to have died from the virus, which appeared in Wuhan city in December. "I am substantially more concerned than I was a week ago," disease outbreak scientist, Prof Neil Ferguson, said. The work was conducted by the MRC Centre for Global Infectious Disease Analysis at Imperial College London, which advises bodies including the UK government and the World Health Organization.
Below is the summary from the disease outbreak scientist, Prof Neil Ferguson:

We estimate that a total of 1,723 cases of 2019-nCoV in Wuhan City (95% CI: 427 – 4,471) had onset of symptoms by 12th January 2020 (the last reported onset date of any case). This estimate is based on the following assumptions: Wuhan International Airport has a catchment population of 19 million individuals. There is a mean 10-day delay between infection and detection, comprising a 5-6 day incubation period and a 4-5 day delay from symptom onset to detection/hospitalisation of a case (the cases detected in Thailand and Japan were hospitalised 3 and 7 days after onset, respectively) Total volume of international travel from Wuhan over the last two months has been 3,301 passengers per day. This estimate is derived from the 3,418 foreign passengers per day in the top 20 country destinations based on 2018 IATA data, and uses 2016 IATA data held by Imperial College to correct for the travel surge at Chinese New Year present in the latter data (which has not happened yet this year) and for travel to countries outside the top 20 destination list.

Caveats

1. We assume that outbound trip durations are long enough that an infected Wuhan resident travelling internationally will develop symptoms and be detected overseas, rather than being detected after returning to Wuhan. We also do not account for the fact that international visitors to Wuhan (such as the case who was detected in Japan) might be expected to have a shorter duration of exposure and thus a lower infection risk than residents. Accounting for either factor correctly requires additional data but would increase our estimate of the total number of cases.
2. We estimate the potential number of symptomatic cases with disease severity of a level requiring hospitalisation (both the cases detected in Thailand and Japan were moderately severe). Our estimates do not include cases with mild or no symptoms.
3. The incubation period of 2019-nCov is not known and has been approximated with the estimates obtained for MERS-CoV and SARS [8,9].
4. We assume that international travel is independent of the risk of exposure to 2019n-CoV or infection status. If zoonotic exposure was biased towards wealthier people, travel frequency may be correlated with exposure. Also, some travel might be causally linked to infection status (to seek healthcare overseas) or the infection status of contacts in Wuhan (this may apply to the case detected in Japan) [10]. Accounting for either association would increase the probability of a case travelling and therefore reduce our estimates of the total number of cases.

Sensitivity analysis

We explore the sensitivity of estimates of total cases to our assumptions about: i) the duration of the detection window (exploring a lower value of 8 days); ii) the catchment population size of Wuhan airport (assuming it might be 11 million, the population of Wuhan city, rather than 19 million, the population of the entire metropolitan area); and iii) true exportations reported internationally (2, 3 and 4 cases). Table 1 summarises the baseline assumptions and alternative scenarios explored. We note that the currently reported number of cases (44) is substantially lower than the lower bound of our most conservative scenario (190 cases, Scenario 3).

Conclusions

It is likely that the Wuhan outbreak of a novel coronavirus has caused substantially more cases of moderate or severe respiratory illness than currently reported. The estimates presented here suggest surveillance should be expanded to include all hospitalised cases of pneumonia or severe respiratory disease in the Wuhan area and other well-connected Chinese cities. This analysis does not directly address transmission routes, but past experience with SARS and MERS-CoV outbreaks of similar scale suggests currently self-sustaining human-to-human transmission should not be ruled out. MRC Centre for Global Infectious Disease

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