Human challenge study of novel coronavirus disease (COVID-19) reveals further insight into how the virus spreads | Teikoku News

A new analysis shows how the SARS-CoV-2 virus spreads from the nose to the air and to surrounding surfaces.

The results of this survey are COVID-19 Human Challenge ProgramLed by Imperial College London and partners*, it provides in-depth insight into how a person infected with SARS-CoV-2 spreads the virus into their immediate surroundings.

In February 2021, 36 healthy young participants who had no previous immunity to the virus became infected with SARS-CoV-2 under controlled clinical conditions that could be closely monitored in the residential facility of the Royal Free Hospital, London. bottom. They remained at the facility until they were no longer contagious.

The facility will allow the clinical team to take swabs from the participants’ noses and mouths daily, as well as environmental samples of the air and swabs from the surfaces of the room, allowing researchers to closely track the course of the infection. I was able to

virus release

A total of 18 of the original 36 participants became infected. Analysis showed that the two released significantly more virus into the air than the other infected participants, but did not show significantly worse symptoms. Researchers suggest that this may represent a small number of individuals who are highly contagious and can sometimes be described as “superspread”.

The analysis found high amounts of viral RNA in air samples, exhaled breath, participants’ wipes, and surrounding surfaces, including frequently touched surfaces such as door handles and TV remote controls, to demonstrate how infected individuals interact with their environment. It can contaminate and spread viruses.

Viral shedding correlated more strongly with levels of virus detected in the nose than in the throat, highlighting that the nose is an important route through which infected individuals shed virus into the air and environment.

According to the researchers, the most recent analysis suggests that the virus can be transmitted from person to person by being released directly into the air, onto nearby surfaces, and from contaminated hands to frequently touched surfaces such as door handles and remote controls. It is said that the route to be transferred to is further highlighted. .

“Reliable indicators”

They also showed that a positive lateral flow test and visible symptoms are reliable indicators of when people are infected and shedding virus into the air and environment. Most of the virus was released after people noticed their first symptoms, and very little was released into the environment before that (before symptoms appeared). They found no significant association between the severity of participants’ symptoms and the amount of virus they shed into the environment.

According to the researchers, the findings highlight the need to reinforce public health messages about proper mask use, hand washing and surface cleaning, and how human stress testing can help combat COVID-19. It is said that it highlights whether it continues to increase knowledge about infection transmission.

Dr. Anika Singanayagam, said NIHR Academic Clinical Lecturer in the Department of Infectious Diseases at Imperial College London and co-first author of the study. Studying infections in a controlled environment allows us to collect unique and detailed measurements of the virus released, which will help us understand when and how COVID-19 patients infect others. You will be able to understand how to These kinds of measurements are difficult to collect in a real study.

“Our data show that many of the viruses people shed originate from the nose, further highlighting the importance of covering not only the mouth but also the nose when using a face mask. But it also shows how the virus can be transferred from hands to contaminated surfaces such as door handles and remote controls and become a source of infection.”

Dr. Jay, Zhou JieA researcher in the Department of Infectious Diseases at Imperial College London and co-first author of the study, said: Make face masks and social distancing more effective. Data from our study highlight that recognizing and addressing the first mild symptoms indicative of infection, combined with frequent self-examination by lateral flow testing, can effectively limit subsequent spread of infection. doing. ”

Professor Wendy BerkleyThe Dean of Infectious Diseases at Imperial College London said: Is the virus most likely to infect others? That information can help us understand how the virus spreads and how best to intervene to stop it from spreading.

“Human challenge studies provide detailed insights into infectious diseases that may not otherwise be available. should be considered as part of our preparedness for

Previous findings

The latest findings add to some important clinical insights already gained from the COVID-19 Human Challenge Program. Published February 2022.

These include that symptoms begin to appear on average two days after contact with the virus, that the infection first appears in the throat, that the infectious virus peaks about five days after infection, and that the throat For example, the nose is much more abundant than the

In the first analysis, the lateral flow test (LFT) is a definitive and reliable indicator of whether infectious virus is present in the nose and throat (i.e., whether it can infect others). I also understand.

“SARS-CoV-2 Viral Release to Air and Environment after Human Attack: Phase 1, Open 1 Label, First Inhumane Study,” published in The Lancet Microbe. DOIs: xxxxxxxxxxxxx

*The Human Challenge Program is a partnership between Imperial College London, the Vaccine Task Force, the Department of Health and Human Services (DHSC), hVIVO and the Royal Free London NHS Foundation Trust.