[Global Times reporter Ni Hao Liu Caiyu] On the morning of the 23rd, Shanghai announced the traceability results of two confirmed cases of new coronary pneumonia on November 9th and 10th. The target was targeted at an aviation container that was shipped back to Shanghai from North America.
This seemingly new way of transmission of the new coronavirus has attracted widespread attention from all walks of life.
Experts told the Global Times reporter on the 23rd that the aerial container is in a cold-chain-like low temperature state when flying at high altitude, which is indeed conducive to the survival of the virus.
In the transportation route of air cargo before arriving at the airport, the number of contacts is numerous, and the risk of overseas import of the epidemic is higher than that of air passengers.
All related to aviation container
Sun Xiaodong, deputy director of the Shanghai Centers for Disease Control and Prevention, reported at a press conference on the morning of the 23rd that the two previous confirmed cases had entered and cleaned an aviation container that had been transported back to Shanghai from North America on October 30.
The container is a closed container with a large amount of shock-absorbing foam, and the internal environment is humid.
When cleaning up, neither of them wore masks.
Sun Xiaodong said, “If we take October 30th as the time for the two of them to be exposed together, then the onset time of the two cases is in line with the incubation period of the onset of new coronary pneumonia. At the same time, after genetic sequencing, the genes of the two cases are highly homologous, and are similar to the North American strain Highly similar, which suggests that the source of infection is foreign input."
Based on epidemiological investigations and gene sequencing, authoritative national and Shanghai experts comprehensively analyzed and judged that the source of infection that led to the two cases can be focused on the simultaneous exposure to the imported aviation container.
Jiang Qing, an epidemiologist and former dean of the School of Public Health of Fudan University, told the Global Times reporter on May 23, “The traceability results of the Shanghai epidemic are very clear, and the two airport workers have not been exposed to the cold chain, so we basically It can be assumed that the two workers were infected while cleaning the aviation container."
How big is the hidden risk of aviation container
The aviation container refers to various types of containers, pallets and auxiliary equipment used to load cargo, luggage and mail on the aircraft.
Although the Shanghai Health Commission did not confirm the type of cargo loaded in the container on the 23rd, Jiang Qingwu believes that general air cargo will not undergo special handling during flight. In the high-altitude and low-temperature environment, the air container is actually in a cold environment. The state of the chain.
Jiang Qingwu said, “The epidemic in North America is severe. It is winter. After the virus in the container was transported to Shanghai in a low temperature environment, it was immediately unpacked, which could easily cause infection of workers.”
Aviation expert Wang Yanan told the Global Times reporter that aircraft cabins are generally divided into two categories, one is pressurized and heated passenger cabins, and the other is non-pressurized or heated cargo compartments.
The new crown virus is at a low temperature of tens of degrees below zero in the latter type of cargo hold, even if the pressure is lacking, it is still a suitable living environment.
Compared with low temperature, a factor that is more conducive to the survival of the virus is that the air circulation speed in the cargo hold is very low, which is conducive to the accumulation and survival of the virus.
Wang Yanan said that the air circulation in the passenger cabin is very fast, but the cargo warehouse lacks the corresponding facilities for rapid air circulation.
In addition, the air circulation system in the passenger cabin has the function of sterilization and disinfection, but the cargo compartment lacks such an environment.
Wang Yanan also reminded that a large number of operators contacted the container before it arrived at the airport, resulting in an extremely complicated transportation environment, and the risk of epidemic input was even greater than that of passengers.
"So for handling goods from areas with high epidemic risk, I suggest that warehouses and cargo handling personnel should have the corresponding knowledge of epidemic prevention and take preventive measures."
Although the results of the epidemic traceability announced in Shanghai this time are different from previous cold chain infections in other places, Jiang Qingwu still believes that the Shanghai epidemic is an epidemic risk similar to cold chain transmission, but the concept of cold chain is carried out. extend.
Jiang Qingwu said, “It reminds us not to focus only on the cold chain of frozen aquatic products, but also to pay attention to the risk of spreading the virus from more goods shipped from overseas.” Wang Yanan reminded us that all except cold chain products Goods shipped overseas should be sampled and tested before they are installed. When the goods arrive at domestic airports, they should be tested to minimize the risk of virus import.
Large-area nucleic acid detection is the key to success
In recent days, confirmed cases have been discovered in Tianjin, Shanghai and Inner Mongolia.
Will the domestic epidemic make a comeback?
Regarding this, Jiang Qingwu believes that these epidemics that have occurred are all independent of each other and related to overseas imports.
"But it also reminds us that there are various channels for the spread of imported epidemic risks. We must be vigilant, especially as we are entering the epidemic period of respiratory diseases, we must not relax our awareness and measures for epidemic prevention and control."
Zhang Boli, academician of the Chinese Academy of Engineering and president of Tianjin University of Traditional Chinese Medicine, said in an interview with the Global Times reporter on the 23rd that large-scale nucleic acid testing is the reason why China has controlled the epidemic in a relatively short time.
He also reminded that with the advent of winter, the general public must not relax their vigilance and insist on wearing masks, washing hands frequently and ventilating frequently.
Zhang Boli told a reporter from the Global Times that after the outbreak, people in high- and medium-risk areas must undergo nucleic acid testing. At the same time, by tracking the recent whereabouts of patients, the places they have visited should be eliminated, and close contacts should be promptly accepted. Isolation and nucleic acid testing.
When the confirmed patient has a wide range of activities and many people in contact, a large area of nucleic acid testing and screening measures are generally adopted.
Zhang Boli told reporters that China would rather check one thousand more than miss one case. This is not a waste of resources, but a scientific cure.
This fully interprets the true meaning of "life is supreme," and it also effectively blocks the source and route of infection.
"The credibility of the government and the sense of responsibility of the masses are the foundation for our smooth progress. Only China in the world can implement such strong prevention and control measures. It is also the reason why we have controlled the epidemic in a relatively short time."
Shanghai reported on the 23rd that on the evening of November 22, Pudong Airport carried out nucleic acid tests on 17,719 relevant personnel, and 17718 had a negative result and 1 had a positive result.
At present, 17 close contacts of the case have been initially investigated, and centralized isolation and sampling and testing are being implemented.
Pudong Airport stated that it will arrange high-risk workers to receive emergency vaccination against new coronary pneumonia on an informed and voluntary basis.
At the same time, strengthen the elimination of inbound cargo, production facilities and working environment in cargo areas.
Zhang Boli believes that patients found in various places and timely and decisive treatment have received good results.
"Cases in many cities also show that my country now has relatively rich experience in dealing with sporadic cases and mature and complete systems and mechanisms, and can control the spread of the epidemic in a timely manner. Compared with the development of epidemic trends in other countries, this can be seen more clearly. ."