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A systematic review suggests that at least one-third of SARS-CoV-2 infections occur in people who have never developed symptoms, providing strong evidence of the prevalence of asymptomatic infections. Provide.
The finding that one in three infected people remains asymptomatic suggests that tests need to be changed, the researchers point out.
“To reduce infections from presymptomatic or asymptomatic people, we need to shift the focus of testing to home screening,” said lead author Daniel Oran, AM. Medscape Medical News.. “Inexpensive rapid antigen testing, which is offered to millions of people for frequent use, can help significantly reduce the spread of the virus.”
The· Systematic review Published online on January 22nd Annual report of internal medicine.
The findings are at a dire time when the official number of COVID-19 cases in the United States exceeds 25 million for the first time. Public health officials have expressed concern about the higher infectivity. Probably more deadly, A variant of SARS-CoV-2, the new presidential administration Improve vaccine distribution And acceptance rate.
The results are also based on previous findings published by the same research team (Oran and senior author Eric Topol, MD). Review See asymptomatic COVID-19 cases. Initial data were more limited, but they also suggested that a wider range of tests was justified, pointing out that asymptomatic individuals could transmit SARS-CoV-2 for up to 14 days. did.Topol is also the editor-in-chief Medscape..
In the current systematic review, the highest quality evidence comes from extensive studies in the United Kingdom and Spain. Nationally representative evidence included serological studies from more than 365,000 people in the United Kingdom and more than 61,000 people in Spain. When analyzed individually, approximately the same proportion of asymptomatic cases emerged. It is 32.4% in the United Kingdom and 33% in Spain.
“It’s very noteworthy that national antibody testing studies in the UK and Spain, including hundreds of thousands, gave almost the same results,” said researcher Oran. About SARS-CoV-2 infection. One-third were completely asymptomatic. ” At the Scripps Research Translational Institute in La Jolla, California.
The systematic review included 43 studies with PCR testing for active SARS-CoV-2 infection and another 18 studies with antibody results indicating current or previous infection. The study was published until November 17, 2020.
Through Twitter, Topol said the assessment of SARS-CoV-2 infection for asymptomatic infections has made great strides since the initial dismissal of its importance. “When Dr. @camilla_rothe reported asymptomatic transmission a year ago, @ NEJM’s report was refuted and despised. She was later named TIME 100 Person of the Year.”
8. When Dr @camilla_rothe reported an asymptomatic transmission a year ago, the @NEJM report was refuted and disparaged. She was later named a TIME 100 Person of the Yearhttps://t.co/vSgQsx1qj8 pic.twitter.com/keNVF2misD
— Eric Topol (@EricTopol) January 24, 2021
No symptom vs no symptom
The term “asymptomatic” can be misleading because some people in this group progress to develop signs of infection. The authors state that this “presymptomatic” patient group is probably a minority. Longitudinal studies show that about three-quarters of people who are asymptomatic with SARS-CoV-2 remain.
Topol predicted that one-third of asymptomatic findings could provide feedback on distinguishing between asymptomatic and asymptomatic individuals. “Some people claim that there is a mix with presymptomatic cases, but a review of all the data confirms that this estimate is conservative,” he tweeted.
5. Based on the totality of the data, we conclude that asymptomatic covid occurs in at least one-third of infections.
Some will argue that there is admixture with presymptomatic cases, but review of all the data supports this estimate as being a conservative one.— Eric Topol (@EricTopol) January 23, 2021
Due to the heterogeneity of study settings, population, and other characteristics, the author was unable to perform a meta-analysis of findings.
Where is the house test?
Based on their findings, Oran and Topol wrote that “the COVID-19 control strategy needs to be modified to take into account the prevalence and risk of asymptomatic SARS-CoV-2 infection.” I will. They provide frequent use of cheap and rapid home examinations to identify asymptomatic or presymptomatic people, as well as financial support, allowing people in this group to isolate themselves. We propose programs and housing offered by the government.
Further research is needed to determine if and to what extent the SARS-CoV-2 vaccine can prevent asymptomatic infections.
Topol and Oran Short video To emphasize the findings from their systematic review.
This study was supported by a grant from the National Institutes of Health.
Intern Med. Published online on January 22, 2021. Full text
Damian McNamara It is a staff A journalist based in Miami. He covers a wide range of medical specialties, including infectious diseases, gastroenterology and critical care. Follow Damian on Twitter: @MedReporter..
