The air transmission rate of the new coronavirus is 1,000 times that of the contact surface

Writing in the recently published “Journal of Exposure Science and Environmental Epidemiology”, scientists in the United States pointed out that after testing samples collected from the air and surfaces around campuses, they found that the probability of people contracting the new coronavirus from the air they breathe is 1000 times the infection from touching surfaces.

Between August 2020 and April 2021, University of Michigan environmental health sciences and global public health professor Richard Naizer and colleagues collected samples using gas pumps and swabs at various locations on the enclosed campus. In total, they collected more than 250 air samples, of which 1.6% tested positive for the new coronavirus. And of the more than 500 surface samples, 1.4% were positive.

The results showed that the most dangerous environment was the gym, where 75% of the air samples and 50% of the surface samples tested positive. None of the samples were positive. Also, samples taken from an office or computer keyboard, light switch, table top, microwave oven, refrigerator handle, or student desk are much less likely to be positive.

The researchers then compared the positive samples to actual Covid-19 cases on campus and found that the probability of contracting airborne Covid-19 particles was about 1 in 100; the probability of contacting contaminated surfaces was 1 in 100,000. The former is 1000 times the latter.

“Our findings suggest that exposure to the virus from the air is much higher than the risk of contracting the virus from surfaces such as doorknobs, drinking fountains, keyboards, desks, sinks and light switches,” Naizer said. While school settings may not be the same as other settings, our findings suggest that people should be more concerned about the risk of inhalation of coronavirus.”

Elizabeth Scott, a professor emeritus at Simmons University who was not involved in the study, said: “There is a growing recognition that Covid-19 is primarily airborne.” But she also cautioned that “when people live together and come into contact repeatedly, The relative chance of COVID-19 transmission through surfaces is also high in homes and dorms on the same surface, and the latest study did not assess this private space risk.”

She further pointed out that it is worth noting that “other respiratory viruses and other bacterial infections are mainly transmitted through contact surfaces, and we need to continue to implement effective and comprehensive hygiene measures on surfaces and the air to prevent the spread of the new coronavirus in the community”.

The global epidemic is still at a high level, and the virus is still mutating

At present, the absolute number of confirmed cases of new coronary pneumonia in the world is still high, the new coronavirus is still spreading rapidly and constantly changing, and the situation of epidemic prevention and control is facing great uncertainty. The WHO emphasized that the epidemic is still a global problem, and now is not the time to retreat from epidemic prevention and control, but to really strengthen the epidemic prevention work that has been put in place. This will keep people’s lives safe and get the economy back on track.

According to the latest data released by the World Health Organization on May 4, the cumulative number of confirmed cases of new coronary pneumonia in the world has reached 512,607,587. WHO Director-General Tedros Adhanom Ghebreyesus called on all countries to continue to monitor the corona virus, “in the face of a deadly virus, we must not turn a blind eye.” Public health experts from many countries have pointed out that the epidemic is not over yet, and it is still necessary to remain vigilant. Some countries choose to “lay flat” as a disregard for life, and those countries that “lay flat” have paid a heavy price.

On May 4, Tedros said at a press conference that the number of confirmed cases of new coronary pneumonia reported in the Americas and Africa was increasing due to the Omicron subtype strain. Van Kerckhofer, technical director of the WHO Health Emergencies Program, said that several countries have detected the BA.4 and BA.5 strains of the Omicron subtype, and researchers have obtained hundreds of gene sequences. The two new subtype strains are being evaluated by WHO. She reiterated her call for countries to continue monitoring and testing for the new coronavirus so that WHO can conduct relevant research and make the best recommendations.

According to the weekly epidemic report released by the WHO recently, the Omicron strain is the mainstream variant that is prevalent in the world. Among the more than 250,000 new coronavirus sequences recorded so far, 99.7% are the Omicron strain. Since its emergence in November 2021, the Omicron strain has evolved numerous subtypes and recombinant strains. Epidemiologists say that the rate of mutation of the new coronavirus has not slowed down, and as the mutation continues, its infectivity may continue to increase.

“The threat of virus variants is very real. The long-term impact of the new coronavirus infection is still unclear. It is necessary to continue to monitor the new coronavirus.” The number of reported cases and deaths continues to decline, and WHO is receiving less information about the spread and genetic sequencing of the new coronavirus, compromising its ability to monitor the trend of the outbreak. “We are getting more and more blind to the patterns of (new coronavirus) transmission and evolution. The virus is not going away because countries stop tracking it. It is still spreading, it is still changing, it is still taking people’s lives,” Tedros said.

“We must strive to achieve large-scale coverage of vaccination, and continue to do a good job in epidemic monitoring and clinical management”

Globally reported cases and deaths have continued to decline since the end of March this year. The WHO said that as some countries drastically reduced the number of tests, the actual level of infection far exceeded the numbers reported by countries to the WHO.

According to estimates, 60% to 80% of the EU population has been infected with the corona virus as of now, Kiriakidis, the European Commissioner responsible for health and food safety, said at a press conference recently. EU member states need to be highly vigilant and prepared for new outbreaks and mutated viruses “because the COVID-19 pandemic is not over yet”. Kyriakidis once again warned member states on May 4 that there are still 90 million people in EU countries who have not been vaccinated, and there can be no complacency in dealing with this epidemic. The danger of a new round of outbreaks always exists.

Affected by the outbreak in South Africa, the number of new diagnoses and deaths in the previously slowed African region has recently risen again, the WHO Regional Office for Africa said a few days ago. African countries should remain vigilant. Machidiso Muti, WHO Regional Director for Africa, believes that the new coronavirus is still circulating, and even more deadly mutant strains may emerge, and surveillance measures still need to be retained while promoting vaccination.

Michael Ryan, executive director of the WHO Health Emergencies Program, said that the new coronavirus and its potential to continue to mutate cannot be ignored at this stage. People are eager to get out of the pandemic, but the undeniable fact is that “the epidemic is still raging. We are still not out of the epidemic.” Van Kerckhoffer also emphasized that now is not the time to retreat from epidemic prevention and control, but to really strengthen the epidemic prevention work that has been put in place. This will keep people’s lives safe and get the economy back on track.

Seth Berkeley, CEO of the Gavi Alliance for Vaccines and Immunization, said that the current world’s immunization gap has eased, but there are still huge differences in immunization levels between countries. Globally, 59% of people have received at least two doses of the covid vaccine, in low-income countries the figure is 44%, and 18 countries have a covid vaccination rate of less than 10%.

Ciro Ugarte, director of the Pan American Health Organization’s emergency health department, warned recently: “We have not reached the point of complete control of infections and deaths, both at the regional and global levels. To end this critical phase, The only way is to strive to achieve large-scale vaccination coverage, and continue to do a good job in epidemic monitoring and clinical management.”

“Abandoning epidemic prevention and control is a disregard for life, and relevant countries have paid a heavier price.”

Public health experts have repeatedly warned that humans still do not fully understand the new coronavirus and cannot predict how the virus will evolve. The British Government’s Scientific Advisory Group on Emergencies believes that considerable uncertainty remains about the pandemic, the higher global prevalence of the new coronavirus provides more opportunities for virus mutation, and humans face a higher risk of emerging new mutant strains. The rationale is to assume that all mutant strains that emerge in the future will be mild.”

However, because some countries and regions could not find an ideal strategy to control the epidemic, coupled with complex factors such as economic downturn and anti-epidemic fatigue, in addition to strengthening vaccination, they no longer emphasized or simply did not take other prevention and control measures. The result has been a surge in cases and a high number of deaths. This approach has been questioned and criticized by many parties.

Mark van Lanster, a well-known Belgian virologist, said in an interview with this reporter recently: “Some countries have not chosen the strategy of maximizing the containment of the virus from the beginning. Some countries have tried, but failed. Controlling the epidemic is not only It tests the government’s social governance ability and the determination of policy makers. Abandoning epidemic prevention and control is a disregard for life, and the relevant countries have paid a heavier price.”

In the United States, which has the largest number of confirmed cases in the world, the U.S. Centers for Disease Control and Prevention’s epidemic curve chart shows that the highest number of new deaths in a single day in the United States appeared on February 1 this year, with 4,184 deaths, and this data occurred in Omic At the peak of the outbreak caused by the Rong strain, after more than 65% of the American population was fully vaccinated. The U.S. death toll from COVID-19 has surpassed 1 million as the virus was allowed to spread.

The Humanities and Social Sciences Correspondence, a subsidiary of the British “Nature” magazine, recently published an article criticizing Sweden’s anti-epidemic strategy, arguing that Sweden’s “natural” herd immunity strategy led to higher mortality. The article pointed out that Sweden’s covid pneumonia mortality rate in 2020 is 10 times that of neighboring Norway. “If Sweden wants to do better in future pandemics, it must re-establish the scientific method.”

In February this year, the UK announced its “Coexistence with Covid-19” plan, lifting all restrictions in a legal sense. Since then, the epidemic in the UK has continued to deteriorate, with infection levels rising to record highs, putting heavy pressure on the health care system. Right now, the UK healthcare system is struggling.

Experts remind that giving up prevention and control poses greater risks to groups such as the elderly, people with underlying diseases and immune-compromised people. South Korean data show that in the first week of April, people over the age of 60 accounted for 85.7% and 94.4% of the severe and fatal cases of new coronary pneumonia, respectively. In addition, more than half of South Korean children aged 9 and under have been infected with the corona virus, and some children suffer from sequelae such as loss of smell.

Viola, a professor of pathology at the University of Padova in Italy, pointed out that the problem of new coronavirus reinfection should not be ignored. After infection with the Delta strain, it is still possible to re-infect with the Omicron strain.

Wendy Buckley, a virologist at Imperial College London, has a negative view on whether the new coronavirus will “continue to weaken its toxicity” after it mutates. Buckley believes that in addition to common mutations, the new coronavirus will evolve rapidly through recombination. If one Omicron variant recombines with another SARS-CoV-2 variant, it is possible to produce a strain that can both immune evasion and cause more severe disease. “It would be good news if these emerging mutants could herald a milder course of the virus, but biology tells us it won’t be like this forever,” Buckley said.

Public health experts emphasized that human understanding of the new coronavirus is still insufficient, the current epidemic is not over, and it is far from the time when the fight against the epidemic is relaxed.

U.S. government agency conceals suspected “virus spillover” incident

The U.S. Centers for Disease Control and Prevention recently confirmed that at least four people in Michigan, U.S., were infected with a strain of the new coronavirus primarily observed in minks in 2020. This is also the first known case in the United States of the possible transmission of the new coronavirus from animals to humans. U.S. media previously disclosed that the U.S. Centers for Disease Control and Prevention concealed the information and delayed it for several months before partially releasing it. The researchers said that the late reporting and concealment of this incident may have hindered the effective monitoring of the spread of the new coronavirus by humans.

According to the website of the National Geographic magazine in the United States, they obtained a batch of US government documents. The documents include emails between the CDC and Michigan public health officials that disclosed a late 2020 CDC investigation into suspected animal-to-human transmission of the coronavirus in Michigan. On October 8, 2020, Michigan public health officials officially sought help from the U.S. Centers for Disease Control and Prevention after it was confirmed that a mink on a mink farm had contracted the new coronavirus and died, documents show. Within days, the CDC sent four veterinary epidemiologists to Michigan to take virus samples for analysis from minks and surrounding residents on the farm.

The report pointed out that of the four new coronavirus infections in Michigan, two were employees of the mink farm, and the other two were not associated with the farm. Experts believe that because the two people who are not related to the mink farm also have related viruses in their bodies, it means that the mutant strain has spread to areas outside the farm. Genetic analysis found that these people were infected with a special mutated strain of the new coronavirus, which had previously been found in minks in Europe and had experienced “mink-to-human transmission”. However, the U.S. Centers for Disease Control and Prevention did not announce the results of the investigation in time, and it was not until March 2021 that in its website information update, it was mentioned that a “small number of people” had been infected with a “unique mink-related coronavirus variant”, “This suggests that minks may have transmitted the virus to humans.”

The report also pointed out that during the investigation, CDC spokesman Nick Spinelli responded that there were similar cases in Europe, so the incident was not “surprising or unexpected.” He has also repeatedly denied that minks have spread the virus to humans in the United States, and that the virus has been circulating in local communities for a long time.

Regarding this incident, the researchers pointed out that delaying the release of relevant information is not conducive to effective monitoring of the spread of the virus. The virus could mutate in another species and then infect humans as a more dangerous or more contagious mutated strain. “This event is a constant reminder that transparency is important,” said Scott Weiss, director of the Centre for Public Health and Zoonotic Diseases at the University of Guelph in Canada. “The sooner people understand the situation, the faster they can act.” He noted , early information on suspected “spillover” cases could have helped other countries improve outbreak surveillance and response.

Earlier, a report released by the U.S. Government Accountability Office pointed out that under the increasingly serious situation of the new crown pneumonia epidemic in the United States, the U.S. Department of Health and Human Services has not played its leadership and coordination role, and it has long had a series of shortcomings. , including failure to clarify the roles and responsibilities of federal, state and regional prevention and control, failure to reasonably collect and analyze epidemic data, lack of transparency in work, and lack of communication and communication with the public. The report believes that these defects not only hinder the current epidemic prevention and control work, but also seriously interfere with the protection and treatment of a series of previous public health problems. “The U.S. federal government has a shameful record of failure in fighting the pandemic,” said Robert Moffett, a senior fellow at the Heritage Foundation.

All 51 cases in Beijing were sequenced as Omicron

On May 1, Pang Xinghuo, deputy director of The Beijing Municipal Center for Disease Control and Prevention and a member of the National COVID-19 expert group, introduced that the Municipal Center for Disease Control and Prevention sequenced the whole genomes of 51 newly infected samples, including 303, 323 and 342, at the 321st press conference on COVID-19 prevention and control in Beijing. The results indicated that all the viruses belonged to omicron variant strains and were highly homologous with the virus sequences of the cluster epidemic in Chaoyang district.

Up to now, 158 locally infected samples have been sequenced since April 22, and sequence comparison results indicate that there are two independent transmission chains in The city, which are completely consistent with the sequence of the recent cluster of cases outside Beijing and the virus spilled to other provinces and cities.