What are the characteristics of the epidemic in Shanghai and the difficulties in epidemic prevention?
Experts: The characteristics of the epidemic in Shanghai are as follows:
First, the main strain of the current outbreak, Omicron BA.2, is spreading very quickly, faster than Delta and past variants. In addition, this strain is highly insidious, and the proportion of asymptomatic infected patients and mild patients is very high, so it is difficult to control it.
Second, the chain of transmission was relatively clear when it was introduced early, but some community transmission gradually emerged. As of today, most communities in Shanghai have had cases, and there has been widespread community transmission. This means that it will be very difficult to attack the Omicron strain in the same way as the Delta strain alone, because it is so widespread that more decisive and determined measures must be taken.
Third, in the prevention and control measures, such as nucleic acid testing, Shanghai has high requirements on its organizational and management capabilities, as well as its prevention and control capabilities. In a city of 25 million people, it is a big challenge for all parties to accomplish a certain action in a certain period of time.
Fourth, traffic in Shanghai. In addition to international exchanges, Shanghai also has frequent exchanges with other parts of China. In addition to preventing the spread of the epidemic in Shanghai, it is also necessary to prevent spillovers and imports from abroad, so it is the pressure of three lines of defense.
Why are there so many asymptomatic cases in Shanghai?
Expert: The omicron variant has a very important related characteristic: the proportion of asymptomatic infected persons is relatively high, which is also fully demonstrated in the current outbreak in Shanghai. There are a number of reasons for the high rate, such as widespread vaccination, which develops effective resistance even after infection. After infection with the virus, patients can become less sick, or even asymptomatic, which is a result of the epidemic prevention.
We’ve been fighting the Omicron mutation for a while, and it’s coming too fast. I have a deep feeling that we can’t beat it with the way we used to fight Delta, Alpha and Beta. Must use faster speed to run, this faster speed is to implement measures to start fast, fast system fast.
Second, the Omicron variant is highly transmissible. Once there, if there is no intervention, it takes 9.5 people per infected person, a figure that is internationally accepted. If measures are not taken firmly and thoroughly, it cannot be less than 1.
So the measures we are taking, whether nucleic acid testing or region-wide static management, are to do everything possible to lower the transmission value below 1. Once it gets below 1, it means that one person can’t transmit to one person, and then there’s an inflection point, and it doesn’t spread continuously.
Moreover, it spreads within a short interval of generations. If the intergenerational interval is long, there is still time to manage and control the discovery; Once it’s a little bit slower, it’s probably not a generational problem, so this is the most difficult thing for us to control.
Doing nucleic acids over and over again, and doing antigens at the same time, is trying to get it clean, trying to expand the scope, finding out all the possible sources of infection, and then managing it, so that we can cut it off. If you miss it a little bit, it will quickly grow exponentially again. Therefore, this is the most important difficulty for prevention and control at present. Shanghai is a megalopolis with a large population density. It will pop up again at some point if you don’t pay attention to it.
As the largest city in China, how difficult is it for Shanghai to carry out the “dynamic zero-out” of the epidemic?
Expert: “Dynamic zero” is the country’s general policy to fight COVID-19. The repeated COVID-19 response has proved that “dynamic clearance” is in line with China’s reality and is the best option for China’s current COVID-19 response.
The core connotation of “dynamic zero clearance” is: when a case or epidemic occurs, it can be quickly detected, quickly contained, cut off the transmission process, and finally detected and extinguished, so that the epidemic does not cause sustained community transmission.
However, “dynamic zero clearance” is not the pursuit of complete “zero infection”. As the Novel Coronavirus has its own uniqueness and strong concealment, there may be no way to prevent the detection of cases at present, but rapid detection, rapid treatment, detection and treatment must be carried out. So it’s not zero infection, zero tolerance. The essence of “dynamic zero clearance” is fast and accurate. The core of fast is to run faster than it for different variants.
This is also the case in Shanghai. We are in a race against the Omicron BA.2 mutant to control it at a faster speed. Really fast, is to discover fast, fast disposal.
Post time: Apr-18-2022