The hospitalization rate for influenza-infected people in the United States in 2011-2019 was 1.6%. If all people with flu symptoms are hospitalized, the demand for hospitalization will be multiplied by several tens, and medical staff will be overwhelmed in any city, and even the medical system will collapse. Fortunately, the Chinese government is devoting all its energy to supporting Wuhan and directly increasing medical supply, which has greatly reduced local panic.
Author: Tencent Finance Contributing James Liang (Ctrip Group co-founder, Chairman of the Board), HUANG Wen – zheng (Dr. Biostatistics at Johns Hopkins University, humanities Research Fellow, Economic Society)
The Spring Festival in 2020 is anxious. With the spread of the new coronavirus pneumonia (referred to as new coronary pneumonia) , the traffic control in Wuhan and Hubei has been implemented. There are 30 provincial-level administrative regions in China One-level responses to major public health emergencies have been initiated one after another, and epidemic control measures have been introduced. But with the increasing number of confirmed diagnoses, these powerful measures have not completely reduced the public’s panic.
According to preliminary data, the spread of neo-coronary pneumonia is relatively strong, but the mortality rate is lower than SARS. Many infected people are asymptomatic or have only mild symptoms, and most of the critical cases and deaths are the elderly and those with underlying diseases. These features of neocoronary pneumonia are similar to influenza, both of which are respiratory infectious diseases, although clinical manifestations are different.
Given the similarities between the new crown virus pneumonia and influenza, we can make a simple comparison of the epidemiological data of the two. Due to different flu statistics in China and incomplete data, we use data from the US Centers for Disease Control and Prevention’s (CDC) to understand the status of influenza in the United States . These data are based on professional data sampling and models, which are stable and comparable between different years.
Table 1: Estimated flu burden in the United States from the 2010-2011 flu season to the 2018-2019 flu season:
![]()
(Data source: US Centers for Disease Control / CDC)
Several ratios of U.S. influenza can be calculated based on the above annual average data:
Prevalence = number of patients / total US population = 28,646,765 / 320000000 = 9%
Sickness of death = deaths / patients = 37462/28, 646, 765 = 0.13%
Disease consultation rate = number of consultations / number of patients = 13,313,372 / 28,646,765 = 46%
Sickness hospitalization rate = number of hospitalizations / patients = 446, 729/28, 646, 765 = 1.6%
Let’s take a look at the latest statistics of Chinese new crown pneumonia.
Table 2: 1/27 and previous Hubei Province and areas outside Hubei: case data:
![]()
(Note: Data source: Hubei Provincial Health Commission, National Health Commission and third-party materials)
Sickness is a key indicator of disease toxicity.
Based on:
Sickness of death = deaths / patients
Number of confirmed patients = number of patients * confirmed diagnosis rate
We can conclude:
SickMortality = Number of deaths / diagnosed patients * Confirmed disease rate
Based on data outside Hubei, we can conclude:
Medical mortality rate outside Hubei = 6/1872 * Confirmed disease rate
= 0.32% * diagnosis rate
Assuming that all patients outside Hubei can be accurately diagnosed with new coronary pneumonia, the diagnosis rate is the consultation rate. According to the 46% consultation rate of influenza in the United States, the mortality rate outside Hubei is 0.32% * 46% = 0.14%, which is only slightly higher than the United States influenza mortality rate of 0.13% in the past few years.
However, it must be emphasized that the above calculations are based on the existing data. As the symptoms of new coronary pneumonia will gradually worsen, it usually peaks in the second week. The infection time outside Hubei is generally later than that in Hubei Province, and the cure rate is currently very low. It cannot be ruled out that the mortality rate will increase significantly in the future. may.
Let ’s look at the situation in Hubei again:
Inner mortality in Hubei Province = 100/2714 * Diagnosis rate of disease
= 3.68% * diagnosis rate
If the 46% prevalence rate is also estimated, the mortality rate in Hubei will be as high as 1.69%, which is much higher than that outside Hubei. But the lethality rate of the same virus is unlikely to be hugely different between different regions in China where the population is genetically similar. Therefore, it is more likely that the diagnosis rate in Hubei is much lower than the national diagnosis rate, because Hubei currently lacks sufficient diagnosis and testing capabilities to diagnose the infected population, and many infected people with mild symptoms may follow the advice to self-isolate at home, so Not yet included in statistics.
In other words, the actual number of people infected in Hubei may be much higher than the number of people diagnosed now. Taking into account that most of the death cases will experience critical symptoms and get medical treatment before death, we can reasonably speculate that the final number of deaths in Hubei will not be underestimated. In this case, the actual infection mortality rate in Hubei Province may be much lower than the above estimates.
Since there is no specific cure for flu, most people with flu will rest at home instead of being hospitalized unless they have severe symptoms. According to the data in Table 1, the hospitalization rate of influenza-infected people in the United States in 2011-2019 was 1.6%. If all people with flu symptoms are hospitalized, the demand for hospitalization will be multiplied by several tens, and medical staff will be overwhelmed in any city, and even the medical system will collapse. Fortunately, the Chinese government is devoting all its energy to supporting Wuhan and directly increasing medical supply, which has greatly reduced local panic.
Because the hospitals in Wuhan and Hubei are currently unable to receive a large number of suspected patients, it is generally feared that many infected people have not been counted, so that the actual number of infected people may be much higher than the number of confirmed diagnoses. Rate also seems to support this speculation.
However, if the number of neonatal pneumonia deaths in Hubei does not increase significantly in the future, even if the number of confirmed diagnoses in Hubei increases significantly, it only means that the actual number of infections is more than expected. The more the actual number of infections, the lower the actual mortality rate in Hubei than the estimated mortality rate based on the number of confirmed Hubei patients. In addition, even if the number of confirmed diagnoses in Hubei does not increase significantly, it may be because many asymptomatic or mildly infected people stay at home and follow the advice, which does not mean that infection mortality outside Hubei is underestimated. The most important thing is that as long as the mortality rate outside Hubei does not increase significantly in the future, the lethality of the new crown virus will not be much different from that of the US influenza.
We can also compare the mortality of new coronary pneumonia with SARS: According to the data of the World Health Organization, as of May 29, 2003, a total of 8295 SARS cases were reported worldwide, 750 deaths were reported, and the mortality rate was 9.04%. . It can be seen that among the three infectious diseases of new crown pneumonia, SARS and influenza, the death rate of new crown pneumonia is closer to influenza, and far lower than SARS.
To sum up, as long as there is no major change in mortality, even if the number of confirmed patients will rise rapidly, we are still cautiously optimistic about the epidemic. Of course, this is not a suggestion to relax epidemic prevention measures, but just hope that rational analysis will help alleviate unnecessary panic. The above analysis also supports the current government’s recommendation for self-isolation at home for asymptomatic or mildly infected persons. No country or city can treat all patients with cold symptoms. Panic consultations and hospitalizations will only increase the burden on the medical system, and may increase the risk of self-infection.
It should be noted that the inference of this article is made based on historical influenza data in the United States and the latest outbreak data. In the future, it is necessary to closely observe the global epidemic data, including data from outside Hubei and other countries. Of particular importance is the death data. If deaths outside Hubei, including China, remain at very low levels for a long time, then this article’s relatively cautious and optimistic speculation can help alleviate general panic.
We also note that the World Health Organization stated on January 23 that the outbreak has not yet constituted a public health emergency of international concern and does not recommend any broader travel and trade restrictions. We do not know whether this decision of the World Health Organization is related to the lower mortality rate outside Hubei, especially the zero mortality rate abroad, but we believe that the analysis provided from the perspective of this article will help the World Health Organization and itsGovernments and companies in other countries can better judge the epidemic situation and take appropriate and rational measures.