The study found that recessive transmission is the main mode of human-to-human transmission of the new coronavirus

6, local time, the
Academy of Sciences (PNAS) published an academic paper, "Hidden transmission of the response to the outbreak of neo-coronary pneumonia" (The financials of the silent transmission for the control of COVID-19 outbreaks). The study found that the spread of the new coronavirus is mainly caused by latent and asymptomatic infections. The study was conducted by scientists from York University in Canada, Yale University in the United States, and the University of Maryland School of Medicine., a key way to control the spread of the virus is to isolate patients with symptoms, but not ignore the large number of asymptomatic and latent infections, the paper said. By modelling, the researchers found that most of the transmission of the new coronavirus is recessive transmission, which is caused by a joint incubation period infection with an asymptomatic infection.
According to the "New Coronavirus Asymptomatic Infection Management Code" issued by the
Joint Prevention and Control Mechanism, asymptomatic infected persons have two conditions: First, after 14 days of isolation medical observation, there are no self-aware or clinically identifiable symptoms and signs;
Professor Jennifer Wright, of N.Y. Langone Medical Center, says the "incubation period" refers to the time period when an asymptomatic infected person does not show symptoms. Previous studies have confirmed that patients in the incubation period of neo-crown pneumonia are the most contagious, which is not common in respiratory diseases. Photo Source: ForbesPrevious studies have found that about 17.9% to 30.8% of all infected people do not show symptoms. Based on the proportion of asymptomatic patients in different cases, the study calculated the corresponding scale of recessive transmission.
assumes that 17.9 per cent of cases in the outbreak did not show symptoms, in which case transmission caused by latent infections can account for 48 per cent of transmission and asymptomatic infections account for 3.4 per cent of transmission. Assuming that 30.8 per cent of cases in the outbreak showed no symptoms, in this case transmission caused by latent infections could account for 47 per cent of transmission and asymptomatic infections by 6.6 per cent of transmission.
, the study concluded that even if people with symptoms were immediately isolated, the outbreak could not be fully controlled and a subsequent large-scale outbreak could still occur.
study found that at least one-third of hidden transmitters must be identified and isolated if the rate of attack is to be kept below 1% if the outbreak is to be brought under control.
authors argue that the results of the study suggest that the government needs to expand testing to screen asymptomatic suspected cases, and that for confirmed cases, their exposure history needs to be tracked as soon as possible to identify patients in the incubation period.
authors say that because asymptomatic infections are difficult to track and various omissions may occur during the isolation period, the study's estimates of the recessive spread of the new coronavirus tend to be conservative, and the actual risk of recessive transmission is likely to be greater. Therefore, the Government should take these risks into account when considering whether to relax preventive measures.
, CNN cites other recent research that says the public can help protect themselves from hidden transmission by wearing masks properly where necessary.