10% of cases lead to 80% of the spread of COVID-19 super-transmitters why?

Since the outbreak of COVID-19, "super-transmitters" have been a topic of worldwide attentionHowever, due to the lack of understanding of super-transmission events, there are many difficulties in studying and analyzing themMay 20, Science published a newsletter that analyzed "super-transmitters" and revealed why some people become super-communicators, while most people don't cause large-scale infectionsMuch of the study of the new coronavirus (SARS-CoV-2) has focused more on its basic number of reproductives (R0), which is the average number of new infections per infected personIt is estimated that in the absence of social isolation measures, R0 is 3, i.ean average of 3 people per patientBut in fact, some people will bring the virus to others, while others will notthat is why, the researchers also used a value called "dispersion factor" (K) to describe the extent of disease aggregationThe lower the K value, the more propagation caused by a few peopleIn 2005, James Lloyd-Smith, a professor in the Department of Environmental Sciences at the University of California, published a study in Nature, found that the K value was 0.16 in the 2003 SARS outbreakLater, researchers estimated that the MERSK outbreak in 2012 had a value of 0.25, compared with 1 K in the 1918 influenza pandemicthe K-value of COVID-19, the researchers differIn January, a study published in Eurosurvese by University of Bern epidemiologists Julien Riou and Christian Althaus suggested that SARS-CoV-2 had a K-value slightly higher than SARS and MERSHowever, a study published in April in the preprinted journal Wellcome Open Research estimated that SARS-CoV-2 had a k-value as low as 0.1, and one of the report's authors, Adam Kucharski of the London School of Hygiene and Tropical Medicine, said, "About 10 percent of cases contribute to 80 percent of transmission." "
a small number of patients causing greater transmission may also reveal some questions about the COVID-19 epidemic, such as why the virus did not spread rapidly globally after its emergence in December, and why cases in France in December did not trigger a widespread outbreak at that timeIf the K value of SARS-CoV-2 is 1, most of the infection chains will disappear on their ownAdam Kucharski believes SARS-CoV-2 needs to be introduced to a new country at least four times without being discovered in order to have a chance to establish itself Why SARS-CoV-2 is more contagious than other coronaviruses, Professor Christophe Fraser of Oxford University School of Medicine suggests that the way the virus is transmitted may be an important factor Studies have shown that SARS-CoV-2 can be transmitted by aerosols, which can be suspended in the air, causing multiple infections, and most group infections seem to suggest this in addition, the different characteristics of patients are also an important reason, some people may spread more viruses than others A 2019 study published in Scientific Reports found that some people exhale more particles when they speak In addition, not washing hands or engaging in too many social activities is also the reason why a person spreads more viruses most of the group infections appear to occur indoors A recent study published by Japanese scholars on the preprinted website medRxiv suggested that the risk of indoor infection was almost 19 times higher than that of outdoor infections, while another report from Chinese scholars suggested that most infections outside Hubei Province occurred indoors time also seems to be a contributing factor On May 19th Chinese academics published a report in Emerging Diseases that two Chinese students who had been quarantined at the hotel appeared to have the ability to transmit the virus before symptoms appeared, and that the samples in the hotel had tested positive Some countries, including China, have initially brought the outbreak under control, but the super-transmission event is likely to undermine these hard-won gains After the outbreak became apparent, South Korea relaxed controls, and a patient who later tested positive for SARS-CoV-2 participated in social activities, so officials tracked down thousands of people and identified 170 new cases it is worth noting that South Korea's large-scale detection capabilities are difficult to achieve in some countries, and that memory bias may also lead to some close contacts not being detected, so some patients may "escape" tracking, in unknown circumstances to cause new transmission The new corona outbreak has infected more than 4.9 million people worldwide, and we still need to be vigilant before this "pandemic" is over (Original title: Science Concern: Why do some COVID-19 patients become super spreaders?) )