How did the frightening SARS finally disappear? I think everyone still has an impression of SARS in 2003. SARS, the full name of clinical medicine is critical subacute respiratory syndrome, which is a subacute respiratory infection caused by SARS coronavirus infection. At that time, SARS was an unforgettable disaster for mankind. In a short time, 32 countries and regions around the world fell on all sides, with a mortality rate of 1 1%.
According to the data analysis, during the spread of SARS, 8422 people were tragically infected with SARS virus in the world, and the total death toll reached 9 19. When it was more serious in China, the number of influenza cases reached 4,986, and the total death toll reached 694, mainly including many medical staff who fought in the front line. Also on July 5, 2003, the World Health Organization announced that the global SARS epidemic was basically over, and no medical records of the group and its animals have been seen since then.
Although we finally defeated the SARS virus, the test never ended. The occurrence of COVID-19 once again revealed people's sufferings and caught them off guard. Compared with the situation when SARS spread for several months, COVID-19's existence time has obviously increased. By 2022, it is the third year, and there is no sign of fading.
Why didn't SARS spread around the world, but COVID-19 broke out around the world? In fact, the biggest difference lies in the spread after the onset of SARS, and COVID-19 can spread it just by touching it. The intensity of COVID-19's disease depends on the fact that both patients in the waiting period and asymptomatic infected people may be infected on a large scale.
We can make a comparison. We assume that the critical period of the virus is one week, and one person can infect two people in one day. These diseases all occur on the eighth day. On the eighth day, SARS patients will cause two people to be infected, and COVID-19 virus carriers may have caused more than 120 people to feel unwell.
From the perspective of SARS prevention and control, as long as the sick patients can be found out at the first time and the close contacts not long ago can be found out, martial law is not needed, and most of them can be stopped. COVID-19, on the other hand, is different. Once the diagnosis is made, it is necessary to check all the contacts of the patient in the past 14 days, and at the same time, it is necessary to check the close contacts of secondary minerals of such contacts again in order to resist COVID-19 under normal circumstances.
However, this is only an ideal situation, which is actually much more complicated than these. With the acceleration of social development and the enhancement of mobility, it is difficult for you to check the relevant close people immediately and then verify their action trajectory. Therefore, if a country conducts an all-round inspection of all close contacts of a geographical error, it can't stop COVID-19 at all.
At the same time, COVID-19 is constantly changing and needs popular science. In epidemiology, we often use an index value R0 (basically the number of infected people) to evaluate the infectivity of a disease, that is to say, a per capita value of a disease will infect several people. If the R0 value is large, it means that the disease is highly contagious.
The average value of R0 in COVID-19 is 3.7, while seasonal influenza is around 1.3. However, such an infectious disease with a R0 value of only 1.3 can affect the business scale of hundreds of millions of people every year. In that case, COVID-19, whose R0 value is 3.7, obviously has a much greater total impact than this one. This means that the population of COVID-19 is unlikely to exceed 1 100 million unless it is controlled immediately.
How the virus will change in the future is difficult to predict at this stage, and strict supervision can only be continued. In addition, among many fashionable infectious viruses, perhaps the only one that people can overcome is smallpox virus. And SARS suddenly disappeared in the right time range. However, reading human history, many viruses will continue to spread from scratch after two years or decades of silence, and the high incidence rate is higher. This means that the SARS virus that we once regarded as defeated does not mean that it is not easy to make a comeback in the future.