A storm of a new pneumonia outbreak from the beef and mutton hall of the Xinfadi wholesale market in Beijing is calming down.
From 0:00 to 24:00 on July 11th, there were no newly confirmed or suspected cases in Beijing. There have been no newly diagnosed cases for 6 consecutive days, and the number of confirmed cases has temporarily stopped at 335.
A month ago, on June 11, "Uncle Xicheng" Mr. Tang was diagnosed with new coronary pneumonia at Xuanwu Hospital in Beijing, breaking the calm in Beijing with no new cases for 56 days and opening the "second season" of the Beijing epidemic. It's just that this season is like a fixed-point annihilation battle, and the troops are quickly withdrawn.
After the diagnosis of "Uncle Xicheng", Beijing locked the beef and mutton hall of the Xinfadi wholesale market as a high-risk location within 22 hours, and conducted quarantine observation on the epidemic-related personnel. This is considered to be the initial short-term victory of the epidemic. The key move.
Subsequent facts prove that almost all the confirmed cases are inextricably linked to the new wholesale market.
Judging from the itinerary tracked by Mr. Tang for the first time released by Beijing Municipal Center for Disease Control, 10 days before the diagnosis, in addition to the new place, there are forest parks, playgrounds, supermarkets, shopping malls, and restaurants. Can you determine the source of the infection?
Staff of the Beijing Center for Disease Control and Prevention, who participated in the epidemic and the handling of major epidemics, said that this was the result of almost 200 hours of sleeplessness among more than 200 disease control personnel.
The last night shift call opened the second season of the epidemic
In the "first season" of the epidemic that began at the beginning of the year, the Beijing Center for Disease Control has assembled a team of two or three hundred people from its affiliated units to form an epidemic special class. Round by round with the new crown virus that is constantly emerging: the epidemic of patients Conduct scientific investigations, determine close contacts, cut off the source of infection, and handle major epidemics.
Around June 10, two or three hundred disease control personnel returned to their posts one after another because of the stable epidemic. Unexpectedly, a call in the early hours of June 11th became the prelude to everyone's return to the "battlefield."
Dou Xiangfeng, who was involved in the last night shift of the new crown epidemic, was the one who answered the phone.
Dou Xiangfeng's record is clearly recorded in the book. At 0:30 on June 11, he received a notice from Wang Quanyi, director of the Center for Infectious Diseases and Endemic Disease Control of the Beijing Center for Disease Control and Prevention: Xicheng District Center for Disease Control reported a positive case of new coronavirus nucleic acid test .
Dou Xiangfeng recalled his mood at the time when he received the notification. If he hadn’t taken into account the other person’s physical condition, he wished he could immediately stand in front of the “Uncle Xicheng” and ask the “three ultimate questions” that the translators are good at: “Who are you?” “Go Where have you been?""Who have you seen?"
While waiting for the dawn, Xicheng District Disease Control Center's first rotation report to Mr. Tang also passed on. Dou Xiangfeng pondered over the trajectory of Mr. Tang 10 days before the onset of illness, and constantly marked his doubts. Mr. Tang should clear every minute.
At 6 a.m. on June 11th, Mr. Tang's retest report for nucleic acid test came out, which was still positive and was officially diagnosed as a case of new coronary pneumonia. From this moment on, the scout squad that traced the source of Mr. Tang's infection quickly entered the "battlefield."
Dou Xiangfeng did not want to wait for a moment. At 7 a.m., he appeared in the fever outpatient clinic of Beijing Xuanwu Hospital, and said to Mr. Tang apologetically, he couldn't wait for a minute, so he should target the high-risk areas as soon as possible.
Colleagues from the Beijing Center for Disease Control commented on Dou Xiangfeng: Fast and quick speech, although the appearance is strong, but the heart is meticulous; there is a set of tricks to do the tune, which can quickly obtain the trust of the investigator and capture the clues of key information to help the investigation The personnel recalled the forgotten key information.
Every piece of memory picked up may be a breakthrough point. Dou Xiangfeng said he would pay special attention to some blank spots on the timeline. For example, Mr. Tang said that taking the child to the playground, Dou Xiangfeng will continue to ask: "What do you do when the child is playing?" Such a reminder reminds him that when the child is playing, he meets an acquaintance, and then Played a game of billiards in the underground billiard hall.
Dou Xiangfeng asked very carefully: When he arrived at the billiard hall, did he set the table himself or the waiter? Is there anyone at the next table? How many people did you contact during this period?
When asked about the details of Xinfa, Dou Xiangfeng even asked which stall he bought something from. Mr. Tang turned over the payment record and confirmed at which stalls he bought fish and meat. These details are the key points for the subsequent sampling personnel to quickly find positive samples in the environment outside the new site.
Dou Xiangfeng and Mr. Tang chatted face-to-face for two or three hours, and later chased several calls, even dating back to his experience at the beginning of the year. Every contact point may be a clue. While chatting, Dou Xiangfeng marked suspicious clues, and these clues should be handed over to other colleagues for investigation.
When Dou Xiangfeng, a fat figure, walked out of Xuanwu Hospital's hot clinic, the clothes in his protective clothing were already soaked.
Expanding the sampling of the trajectory of "Uncle Xicheng", there is a little light in the mist
At 4 pm on June 11th, the Beijing Municipal Government Information Office epidemic situation briefing was held suddenly for several days. Pang Xinghuo, deputy director of the Beijing Center for Disease Control, issued a brief message, which was quite explosive. She informed that a new case of new pneumonia was diagnosed in Beijing, and emphasized that the patient had no recent history of Beijing.
Despite this, several rumors about Mr. Tang were quickly circulating on the Internet. Hundreds of disease control personnel in Beijing are burning brain investigations based on Mr. Tang's track for more than 10 days, and the city is hunting down the virus. The more rumors are flying, the more the disease control personnel must sink their minds to trace the source as soon as possible, and not let go of the clues.
Ren Zhenyong of the Infectious Diseases and Endemic Disease Control Center of the Beijing Center for Disease Control and the New Crown Prevention and Control Field Team is one of hundreds of on-site tracers. Early in the morning on June 11, the group he led was stationed in the community where Mr. Tang's house is located. The main task is to conduct rheology, nucleic acid detection and external environment sampling for all residents in the community.
The mystery to be solved in this session includes whether Mr. Tang was infected in the community, or whether Mr. Tang was infected by him among the close contacts in the community.
Ren Zhenyong carefully observed the community where Mr. Tang lives. Strictly speaking, it is not a large-scale community. In addition to the building where Mr. Tang's house is located, there are two doorways, and there is another building next to it. "At that time, consideration was given to sharing channels, fitness equipment, etc., and increased inspection efforts." Ren Zhenyong recalled.
The hard task of this day is to perform nucleic acid detection on 430 people and nucleic acid sampling on the outside environment of the community, as well as to tune Mr. Tang's close contacts to see if there are suspicious clues.
It is a big project to complete the nucleic acid sampling of more than 400 people in the shortest possible time. For Ren Zhenyong, there are many issues to consider. At that time, the situation was unclear, and it was uncertain whether there was a source of infection in the neighbors, so it was necessary to carefully consider where to sample and how to effectively prevent potential cross-infection.
More than 400 people, including Mr. Tang’s family, had negative test results, and there was no clue about the community’s affiliation. There appeared to be no source of infection in the community and among those in close contact with Mr. Tang. After chasing for most of the day, I was both happy and worried. Fortunately, the community is safe; worryingly, there is no clue to the source.
Simultaneously with the community's tune-up, there is also a survey of Mr. Tang's recent close contacts, but it seems that there is no trace of the virus. None of the people around him have a history of direct contact with the new coronavirus. There are no diagnosed patients or suspects. There are no patients, no people from the epidemic area, and no foreign personnel.
The clue is broken. So the disease control personnel decided to expand the sampling range and find new breakthroughs. At this time, the detailed tunes made by Dou Xiangfeng and the Xicheng District Disease Control Center came in handy. Mr. Tang went to 3 stalls in the beef and mutton hall of Xinfadi. These 3 stalls were sampled by the Disease Control Center of Fengtai District; the forest park where Mr. Tang went was sampled by the Disease Control Center of Haidian District...
In the evening of June 11, Beijing’s Daxing District also reported a patient who had a positive nasal coronavirus nucleic acid detected by a pharyngeal swab. This patient also had a history of new contact. This intersects with Mr. Tang’s many trajectories. The investigators on the scene seem to sniff It's the breath of the virus. This night, thousands of data came together, and almost all the disease control personnel at the scene were picking up lights at night.
At around 4 a.m. on June 12, a test report completed by the Fengtai District CDC was sent to the Beijing CDC, and a positive nucleic acid was detected in the environment outside the beef and mutton hall in the Xinfadi wholesale market.
Ren Zhenyong said that when he saw the report, everyone was very excited. Combining with the confirmed cases in Daxing District, I felt that I would get to the source.
At this time, only 22 hours had passed since Mr. Tang was diagnosed.
The high-risk point is in the Xinfadi wholesale market
Although the information obtained in 22 hours is relatively thin, it is enough to conduct a detailed investigation of the beef and mutton hall in Xinfadi.
Zhai Shuguang, the team leader of the on-site working group of the Beijing CDC's epidemic prevention and control team, remembers that at 6 or 7 in the morning on June 12, a call order was issued in the working group of the already silent on-site group. Carry out flow adjustment and on-site sampling at the development site. Zhai Shuguang said that one or two hundred people quickly said they would join the second season of fighting.
In the first batch, the Beijing CDC almost went to a team of 50 or 60 people, some of them collected throat swabs from 500 merchants in the beef and mutton hall, and the other part of each group was a group of 3 people. Sampling outside.
Ren Zhenyong said that all the most experienced team members of the Beijing Center for Disease Control and Prevention went to the scene, especially those who collected pharyngeal swabs for merchants were stable and fast masters.
On June 12, the highest temperature in Beijing was 34 degrees Celsius. The beef and mutton hall was not well ventilated. The humidity and temperature were high. The secondary protection was almost suffocating. But in order to give clear information as soon as possible, the work of the disease control staff has almost never stopped.
The colleague who took the throat swab with Ren Zhenyong was Li Shuang, a well-known "female man" from the Beijing Center for Disease Control. She used to enter the isolation ward, and it was nothing to say about 30 or 40 people. The iron man she was almost knocked down by continuous combat. She recalled that her mask was sweaty at the time, and she was choked with sweat when she lowered her head.
Despite wearing protective clothing, the people they face directly and the environment they are in are extremely high risk. Ren Zhenyong said that when the 100th person was collected, Li Shuang could not hold on. As a result, the 101st merchant who collected throat swabs tested positive for nucleic acid.
Ren Zhenyong remembered that they had exhausted pharyngeal swab sampling on the semi-ground slope of the beef and mutton hall at that time, and colleagues in the environmental sampling group were even hotter and hotter in the hall.
The team of Ye Yan, deputy director of the Occupational Health Center of Beijing Center for Disease Control, is responsible for collecting samples of the environment outside the beef and mutton hall in Xinfadi. Since the outbreak of the new epidemic, they have countless times walked into the "Red Zone" beef and mutton hall, each time has a different focus, such as a newly diagnosed case, may have to go to the stall operated by the patient again Check again. But the scene of walking into the Xinfadi beef and mutton hall for the first time was the most impressive.
Ye Yan recalled that the first feeling was big, but it was damp, dark and airtight, and it was really suitable for virus concealment.
Environmental sampling requires that every stall be collected, such as knives, cutting boards, sewers, floor drains, freezers, parts that people often touch, and parts that are not easily disinfected by daily disinfection, as well as toilets and door handles. A group of two or three people, one to smear, one to record and label. Thousands of samples were collected in one day.
At the press conference on the afternoon of June 13, Pang Xinghuo reported that on June 12, the disease control personnel conducted sampling and testing of the environment and practitioners in the new market, and found that 40 environmental specimens tested positive for nucleic acid, and 45 people swallowed The swab nucleic acid was positive, all from the environment and practitioners on the negative floor of the trading floor of the Xinfadi market.
Such a clear piece of evidence is the "real hammer" given by fifty or sixty disease control personnel after locking the new site as the source on June 12.
In the early morning of June 13, the relevant departments of Beijing Fengtai District made a decision to temporarily suspend the market for the new development.
On June 18, the chief expert in epidemiology of the Chinese Center for Disease Control and Prevention judged that the epidemic in Beijing had been brought under control only 7 days after the outbreak. In his view, quickly locking the new land as a high-risk point is the basis for the Beijing epidemic to be controlled quickly and accurately.
Some professionals commented that it took only 22 hours to locate the source of the epidemic, which is a classic case of textbook level. In this regard, Ren Zhenyong said that we do trace the source according to the logic of the textbook. For the control of infectious diseases, the logic of the textbook is to find and cut off the source of infection as soon as possible.
China Youth Daily · China Youth Daily reporter Liu Shixin Hu Ning Source: China Youth Daily
Edition 03 July 2020