High temperature in summer may not inhibit the survival of new coronavirus on plastic for 72 hours

category:Global
 High temperature in summer may not inhibit the survival of new coronavirus on plastic for 72 hours


So, how long can the new coronavirus survive in various environments, especially in refrigerated environment? How strong is the ability of the virus to infect people? Since the outbreak of novel coronavirus pneumonia earlier this year, the relevant research and experiments of scientists have never ceased. We specially invite Zhang tiankan, a famous biological science writer, to answer the questions to the readers.

Q: how strong is the new coronavirus in different environments?

A: a widely cited study can provide some evidence for the survival time of the new coronavirus in different environments.

An article published in the American New England Journal of Medicine on March 17, 2020 compares the survival time of new coronavirus and SARS coronavirus in a variety of substances in the environment at a specific temperature. The experimental environment is 21 u2103 - 23 u2103 and 40% humidity. There are five kinds of substances in the environment, which are aerosol, plastic surface, stainless steel surface, copper surface and cardboard surface.

The results showed that the survival time of the new coronavirus was similar to that of SARS virus in aerosols, and it could survive within 3 hours, and the infectivity decreased slightly with the increase of time.

In the other four environmental substances, the survival and infectivity of the new coronavirus are from high to low: plastic, stainless steel, cardboard and copper.

On the plastic surface, the new coronavirus 72 is active (infective). On the surface of stainless steel, the new coronavirus can survive for 48 hours, but the infective viral load is significantly reduced. On the cardboard, the new coronavirus has no infectivity after 24 hours. On the copper surface, the new coronavirus could not detect infectivity after 4 hours.

Q: how long can the new coronavirus survive in refrigerated environment? This is a matter of great concern to many readers. Is there any experimental research in this field?

A: the research mentioned above only shows the survival time and infectivity of the new coronavirus at room temperature (21 u2103 - 23 u2103), and does not indicate whether the new coronavirus can maintain its vitality for a longer time and is more infectious at low temperature. So, how long can the new coronavirus survive in refrigerated environment? At present, there seems to be no relevant literature to record the experimental research in this area.

In the past, there have been tests on other viruses. In May 2010, an experimental study was published in the Journal of applied environmental microorganisms. The original research goal was to point to SARS coronavirus. However, due to the high infectivity and difficulty in obtaining SARS virus, researchers carried out a substitution test with two other viruses, gastroenteritis virus (TGEV) and mouse hepatitis virus (MHV), and concluded that the two viruses were at a certain temperature and humidity Survival on stainless steel surface.

In general, TGEV and MHV can survive for 28 days at 4 u2103 and 20% RH, and the degree of inactivation is the lowest at 20% RH. At all humidity levels, virus inactivation was faster at 20 u2103 than at 4 u2103, and faster at 40 u2103 than at 20 u2103. In a certain range, the higher the relative humidity, the faster the virus inactivation. When the relative humidity is 50%, the virus inactivation is the fastest. This study shows that the higher the temperature is, the worse the survival of TGEV and MHV, and the higher the relative humidity is, the worse the survival of these two viruses.

On June 19, Beijing inspectors took the inactivated samples out of the freezer for the next experiment.

However, this study is not aimed at the new coronavirus and SARS virus, it is only the result of the study on the replacement virus gastroenteritis virus and mouse hepatitis virus, so it can not fully explain the problem. Li Lanjuan, academician of the Chinese Academy of engineering, also pointed out recently that the new coronavirus is a new virus, and it has only been 8 months since its emergence. Further research is needed on its understanding and cold resistance.

Q: how infectious is the new coronavirus in summer? Is there any relevant case study at present?

A: when the SARS epidemic broke out in 2003, the SARS virus disappeared in June, and the SARS epidemic also ceased. Novel coronavirus pneumonia is also a common hope. Many people have a hope that the new crown virus will disappear in the hot season.

But now the novel coronavirus pneumonia is rising in Beijing.

It shows that high temperature in summer may not inhibit the survival and infectivity of the virus. Another study on the new coronavirus also gives some scientific evidence.

Shen Hongbing, academician of Chinese Academy of engineering, Wang Qilong, affiliated Huaian First Hospital of Nanjing Medical University, and others published a research result online in the Journal of American Medical Association on March 30, 2020. A novel coronavirus pneumonia patient with a history of contact with Jiangsu was infected in 8 cases in a hot and humid environment in a public bathhouse in Huaian, Jiangsu, in mid 1 March. The mens area of this bathing place is about 300 square meters (including a swimming pool, shower and sauna), the temperature is as high as 25 u2103 to 41 u2103, and the humidity is about 60%. The first patient confirmed by the bathhouse has been to Wuhan and has a history of contact with Wuhan. He began to cough on January 15, took a bath in the bathhouse on January 18, and began to have fever and was diagnosed on January 19. The other eight patients had no contact history in Wuhan. They took a bath and sauna in the same bath center on January 19 (patients 2, 3, 4), January 20 (patients 5), January 23 (patients 6, 7), January 24 (patients 8). Patients 9 worked in the bath center, and they fell ill on January 30. Therefore, the researchers believe that the new coronavirus can survive in high temperature and humidity environment, not disappear with high temperature.

Q: how many new coronaviruses can cause disease? Is there any relevant research findings at present?

A: the living space of the new coronavirus is large, so what about its infectivity or infectivity? There are two aspects. One is whether the virus load (titer) in the secretion of patients or infected persons is more or less, and the other is whether the load of new coronavirus on environmental objects is more or less. According to the general law of virus transmission, if the viral load is high, the infectivity will be strong, otherwise, the infectivity will be low. However, this situation is not absolute, because even if the number of viruses discharged by patients is large, if some of them are not strong, they will not be infectious, and the infectivity will not be high; on the contrary, even if the viral load is low, but the activity of all viruses is strong, and the infectivity will become strong.

On June 19, the staff of Wanyuan Jiqing agricultural and sideline products market in Daxing District, Beijing were killing the market environment in an all-round way.

23 novel coronavirus pneumonia patients in University of Hong Kong research team found that

The novel coronavirus pneumonia in patients with salivary gland showed the highest viral load in the first week of fever and cough.

The results were published in the Lancet Infectious Diseases on March 23, 2020. Among the 23 patients, 10 were severe and 13 were mild. Saliva test showed that 3 of 23 patients did not detect viral RNA, and the median saliva viral load of the other 20 patients was 5.2 times of 10 copies / ml. The viral load will gradually decrease after the peak in the first week after symptoms, but there is no such trend in the detection of tracheal aspirates such as pharyngeal swabs in severe patients.

Novel coronavirus pneumonia was released in June 16th in Hebeis male New District. 3 of the 2 confirmed cases have a fever of 10 months in June 11th (with a quilt), and fever in June 13th.

(function(){( window.slotbydup=window .slotbydup||[]).push({id:u6056789,container:ssp_ 6056789, async:true (February 25, 2020), novel coronavirus pneumonia confirmed in Hongkong, eighty-third cases of new crown pneumonia confirmed in Hongkong, where the 7 cases were confirmed by the Fu Hui house Buddhist hall in the Mei Lou building, North Point. 2 novel coronavirus positive samples were detected in the Buddha Hall, one of which was on the surface of the classics, the cover and kneeling pad, and the other one in the restroom faucet handle. The above cases mean that new coronavirus can be left on objects in public places. Therefore, no matter whether the virus load in the environment is more or less, wearing masks, washing hands frequently, not gathering, talking about hygiene, reducing touching eyes and mouth with hands are the best way to prevent new crown virus infection. Relevant recommendations India launched a new crown magic medicine to treat the positive patients, claiming that the shortest three days to turn negative in Beijing: food will not be infected with the new crown virus, but it may be polluted. In the UK, saliva will be used to test the new crown virus for 48 hours, and the test results can be obtained. Source: Beijing Daily, editor in charge: Yao Yu_ NBJS10892

In February 25, 2020, novel coronavirus pneumonia was confirmed by eighty-third new cases of new crown pneumonia in Hongkong, Hongkong, and 7 cases were confirmed by the center for health protection in the North American corner. 2 novel coronavirus positive samples were detected in the Buddha Hall, one of which was on the surface of the classics, the cover and kneeling pad, and the other one in the restroom faucet handle.

The above cases mean that new coronavirus can be left on objects in public places. Therefore, no matter whether the virus load in the environment is more or less, wearing masks, washing hands frequently, not gathering, talking about hygiene, reducing touching eyes and mouth with hands are the best way to prevent new crown virus infection.