As of the early morning of this morning, 75 cases of local positive infections have been detected in Beijing, and the cases have spilled over to 4 provinces and 7 places.
It was a sudden outbreak, with the new poison king Aomi Kerong and the old drug king Delta getting together and spreading in a city at the same time, and the source of the virus is still controversial.
By January 26, Fengtai District has launched the third round of full nucleic acids, other areas of Beijing related to infected people have also begun small-scale full nucleic acids, and outside of Beijing, many provinces and cities are urgently adjusting the policy of returning from Beijing...
Near the end of the year, in Beijing, a city of more than 20 million people, although this wave of epidemic has not yet erupted, the cases of continuous climbing have made many citizens worry that the epidemic before the Spring Festival will become a protracted battle.
The two-line outbreak of Aumichron and Delta
From the perspective of the chain of transmission, the current round of the epidemic in Beijing is a two-line epidemic jointly initiated by the Olmi kerong strain and the Delta strain.
The case of the Omiljung strain that appeared on January 15 was regarded as the first time of the current round of the epidemic, fortunately cut off in time, and the new cases in the following days were basically from the controlled population, with a cumulative case of 6 cases, and no new cases since the 22nd.
On January 18, another "Delta strain cold storage transmission chain" marked by a chaoyang searching uncle who tested positive began and quickly became the main chain of spread of this round of the epidemic.
The transmission chain caused by this Delta virus revolves around three cold storage ("cold storage at No. 8 North Guangyangcheng Street, Fangshan District", "Yuquanying Fruit Cold Storage in Fengtai District" and "Cold Storage in the Southwest Suburbs of Fengtai District"), and the concentrated characteristics are: the cases have been directly or indirectly related to cold chain items or related practitioners, multi-point objects are transmitted to people, and the transmission trajectory is clear.
Since January 19, two cold storage stevedores in Fangshan Cold Storage were the first to be tested positive; on January 21, the relevant staff of Yuquanying Fruit Cold Storage and Southwest Suburb cold storage were tested positive for the first time. Since then, Delta virus has gradually spread among neighbors, colleagues and family members of cold storage workers.
It is worth noting that the cold storage at No. 8 North Guangyangcheng Street in Fangshan District is about 28 kilometers away from the other two cold storages, and from the current public epidemic notification, the only meeting point for the 3 cold storage personnel is the Huaxing Restaurant in Fengtai District. Up to now, many infected people have gone to Huaxing Restaurant.
Since then, Daxing District, Chaoyang District and Xicheng District have maintained zero new records for 100 days, which have been broken one after another.
As of press time, there have been 69 cumulative cases in the delta virus transmission chain, of which the largest number of related cases are located in cold storage in the southwest suburbs.
Transmission is suspected to be related to the cold chain, making the already severe and complex prevention and control situation in Beijing, with a population of more than 20 million, more strained.
Wang Peiyu, a professor at the School of Public Health of Peking University, told Eight Point Jianwen that one of the epidemics in Beijing was caused by contaminated international mail, and the other transmission chain was transmitted to people through the cold chain, and it was spread to several people who came to the cold storage, and then infected their families and close contacts.
The impact of the cold chain is also reflected in the spillover. In just 10 days, the epidemic has spilled from Beijing to Jinan and Liaocheng in Shandong, Datong in Shanxi, Shenyang in Liaoning and Xiong'an, Baoding and Sanhe in Hebei Province, a total of 4 provinces and 7 places, and the trajectory of infected people released in these areas shows that most of these spillovers are related to cold chain or cold chain practitioners.
Zhao Dahai, professor at the School of International and Public Affairs of Shanghai Jiao Tong University and executive director of the Shanghai Jiao Tong University-Yale University Joint Research Center for Health Policy, told Eight Point Jianwen that the current round of epidemic in Beijing is not unexpected, whether in Beijing or other parts of the country, cold storage is a weak link in epidemic prevention and may become a "blast window" for the epidemic.
People who are undergoing nucleic acid testing Image source: Visual China
The cold storage in the north that has been repeatedly breached
After Xinfadi, the outbreaks caused by the cold chain have been repeatedly staged, becoming the source of local transmission alongside imported cases.
Virology expert Chang Rongshan analysis, cold storage of quick-frozen and low temperature storage at -22 ° C ~ -30 ° C below, under this temperature conditions, studies have shown that the new crown virus can be stored at -20 ° C chicken surface, 20 days later is still active, and the cold and humid environment is conducive to the virus to maintain activity, workers in the cold storage and expired meat food discarded stacking point (contacted by animals) frequent exchanges, there is a risk of being "material-to-human".
And compared to the normal temperature conditions, the cold storage disinfection effect will also be discounted, Wang Peiyu explained to eight points of Jianwen, frozen items are difficult to completely kill, disinfectant can only act on the surface of the items, ice and places covered by ice are difficult to reach.
In July 2020, an outbreak of 118 people broke out in Dalian, which is suspected to have originated in the processing workshop of a seafood company.
In November, there were 2 cases of infection associated with The cold storage of Tianjin Hailian, and Zhang Ying, deputy director of the Tianjin Municipal Center for Disease Control and Prevention, introduced at the press conference that the source of infection of the epidemic was the pig head imported from North America.
In December, an outbreak of community transmission triggered by an infection spillover from cold chain workers in Dalian caused a total of 83 people to be infected.
After repeatedly breaking the defense, Dalian requires cold chain products to "batch testing, piece disinfection", closed-loop management of the whole process from the port to the cold storage transfer, the implementation of the stationary system for the cold storage of cold chain enterprises, the listing is responsible, the front-line personnel of the cold storage are fixed and centralized, and the people and the environment do nucleic acid testing at least once a week to ensure full coverage and no omission.
"Not allowing cold storage staff to go home and live in a concentrated way, everywhere is operating like this, in principle, it is so required, but it is difficult to achieve, and a long period of closed loop will cause trouble to the daily life of workers," Zhao Dahai said.
In November 2021, Dalian broke through the defense again, and a worker of Dalian Keqiang Food Co., Ltd., the first station of the designated cold storage, was diagnosed and pulled out of the food factory, university town and other places to gather the epidemic situation, and in December, 42 responsible persons of the food factory, testing clinic, killing company and related functional departments were held responsible.
"Although it is difficult to confirm the specific transmission path scientifically, this phenomenon exists objectively," Chang Rongshan told Eight Point Jianwen, "The risk of cold chain, especially cold storage infection, has been underestimated before, and the beijing cold storage epidemic has once again reminded that northern cities where similar epidemics have occurred should focus on monitoring cold chain workers as high-risk groups."
A number of experts suggest that the frequency of nucleic acid testing for cold chain workers should be increased from at least once a week to once every 3-4 days.
An epidemiologist also suggested that routine testing should also focus on environmental sampling of cold chain waste, because it is not excluded that expired frozen meat treated by cold storage, cats, dogs, rats and other animals attracted by food waste play a certain role in the transmission.
"Once the cold storage infected person is found, the nucleic acid of all the relevant practitioners in the city can be quickly started", Chang Rongshan told Eight Point Jianwen, the work and life trajectory of the cold storage practitioners is relatively single and concentrated, and early detection of fast screening may avoid spillage.
Ended after the Spring Festival?
When will the outbreak in Beijing end?
"It should take about 1-2 weeks to be able to control";
"It could last for another 10 days or so"...
A number of experts told eight points of jianwen that the current round of epidemic in Beijing has reached the middle and late stages, the transmission chain is relatively clear, there has been no community transmission, it is expected that there will be no large-scale transmission, and it can end a few days after the Spring Festival.
Zhao Dahai explained that fortunately, the epidemic is mainly transmitted by cold storage, which is a relatively narrow transmission chain, not a wide-caliber community outbreak.
Wang Peiyu told Eight Points Jianwen: The current situation of this wave of epidemic in Beijing, on the one hand, is that Beijing's control of the transmission chain is relatively rapid and has not spread to the community; on the other hand, the chain of cold storage transmission is the Delta strain, if it is the Omicron strain, the possible spread range will be greater than the current.
Of course, at the moment of the large population flow during the Spring Festival, there is also a risk of spillover that makes the public and various places nervous.
It has spilled over to 4 provinces and 7 places, which has made many provinces and cities urgently adjust the policy of returning from Beijing, and the most commonly heard sentence in the phone between local community control personnel and returnees is often: "The policy is changing every day, and we must confirm it with us again before returning home." ”
Wang Peiyu believes that at present, the transmission chain of the epidemic in Beijing has been investigated relatively clearly, and the close connection and sub-close connection have been controlled, and the risk of further spillover and spread is not large.
Zhao Dahai said that There is still room for improvement in the early monitoring and accurate prevention and control of the epidemic in Beijing, but the time for the control of close and sub-close connection, and the time to find out the source and transmission chain is not too late, otherwise the sporadic cases that are currently spilling out in Beijing have long become "major outbreaks".
Migrant workers who have been drifting north for a whole year are also paying attention to the changes in the epidemic situation in Beijing in real time, and the hope of the returnees is very simple, only hoping that a small piece of the world where they work and live, not because of the new cases are classified into medium and high-risk areas, and they can return to their hometowns safely and steadily for the Spring Festival.
Li Lin and Yu Huanhuan wrote
Li Shanshan and Xu Zhuojun are responsible for editing
This article was first published on the WeChat public account "Eight Points Health" (ID: HealthInsight)
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