via Scripps Research
Analysis of data from 16 groups of COVID-19 patients suggest “silent” carriers may exacerbate efforts to stop spread of the disease.
An extraordinary percentage of people infected by the virus behind the ongoing deadly COVID-19 pandemic—up to 45 percent—are people who never show symptoms of the disease, according to the results of a Scripps Research analysis of public datasets on asymptomatic infections.
The findings, recently published in Annals of Internal Medicine, suggest that asymptomatic infections may have played a significant role in the early and ongoing spread of COVID-19 and highlight the need for expansive testing and contact tracing to mitigate the pandemic.
“The silent spread of the virus makes it all the more challenging to control,” says Eric Topol, MD, founder and director of the Scripps Research Translational Institute and professor of Molecular Medicine at Scripps Research. “Our review really highlights the importance of testing. It’s clear that with such a high asymptomatic rate, we need to cast a very wide net, otherwise the virus will continue to evade us.”
Together with behavioral scientist Daniel Oran, Topol collected information from testing studies on 16 diverse cohorts from around the world. These datasets—gathered via keyword searches of PubMed, bioRxiv and medRxiv, as well as Google searches of relevant news reports—included data on nursing home residents, cruise ship passengers, prison inmates and various other groups.
“What virtually all of them had in common was that a very large proportion of infected individuals had no symptoms,” says Oran. “Among more than 3,000 prison inmates in four states who tested positive for the coronavirus, the figure was astronomical: 96 percent asymptomatic.”
The review further suggests that asymptomatic individuals are able to transmit the virus for an extended period of time, perhaps longer than 14 days. The viral loads are very similar in people with or without symptoms, but it remains unclear whether their infectiousness is of the same magnitude. To resolve that issue, we’ll need large-scale studies that include sufficient numbers of asymptomatic people.
The authors also conclude that the absence of symptoms may not imply an absence of harm. CT scans conducted on 54 percent of 76 asymptomatic individuals on the Diamond Princess cruise ship, appear to show significant subclinical lung abnormalities raising the possibility of SARS-CoV-2 infection impacting lung function that might not be immediately apparent. The scientists say further research is needed to confirm the potential significance of this finding.
The authors also acknowledge that the lack of longitudinal data makes distinguishing between asymptomatic and presymptomatic individuals difficult. An asymptomatic individual is someone who is infected with SARS-CoV-2, but never develops symptoms of COVID-19, while a presymptomatic person is similarly infected, but will eventually develop symptoms. Longitudinal testing, which refers to repeated testing of individuals over time, would help differentiate between the two.
“Our estimate of 40 to 45 percent asymptomatic means that, if you’re unlucky enough to get infected, the probability is almost a flip of a coin on whether you’re going to have symptoms. So to protect others, we think that wearing a mask makes a lot of sense,” Oran concludes.
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Asymptomatic Covid-19 infections
- World's weekly COVID-19 cases down 17%; Japan sets 247,830 daily infections record
The COVID-19 situation is easing worldwide with a weekly 17% cases decline and 11% deaths decrease though Japan had one-quarter of the infections and daily record 247,830 cases plus 215 daily deaths.
- For those who have coronavirus, how do you determine when you are no longer contagious?
And the tests are much more available now than they were when the CDC first released its guidance and provided its online self-checking calculator for patients to determine where they are in the ...
- COVID-19 in Shanghai: no new local cases, 11 imported infections
The city reported no local confirmed or asymptomatic cases, three imported confirmed cases and eight imported asymptomatic infections on Saturday, said the Shanghai Health Commission on Sunday morning ...
- What looser COVID-19 safety guidelines could look like
Reports indicate the U.S. Centers for Disease Control and Prevention could loosen some COVID-19 guidelines regarding quarantining and social distancing in the near future, but some health officials ...
- The future of long COVID-19 has societal and financial implications
Earlier this week, the Biden administration released two long-awaited reports, both focused on the understanding and treatment of long COVID-19. The phenomenon is still difficult to understand, both ...
Go deeper with Google Headlines on:
Asymptomatic Covid-19 infections
Go deeper with Bing News on:
- Be the first to know
Get local news delivered to your inbox! Here is everything you need to know about the 2022 Pinnacle Bank Championship. Online ticketing available at thepinnaclebankchampionship.com. Tickets also sold ...
- Ukraine Live Briefing: Fresh shelling at nuclear plant as U.N. warns of possible ‘disaster’
The shelling of the Zaporizhzhia nuclear power plant in southeastern Ukraine highlights the potential for “catastrophic consequences” ...
- China Makes ‘Simulated Attack’ On Taiwan As Beijing-Washington Communications Go Silent
Chinese jets cross the Taiwan Strait's median line and warships shadow each other as Beijing's military drills continue around the island.
- OnePlus Nord 20 SE Surprises Everyone With A Silent Launch
Another OnePlus smartphone has been launched, kind of. The OnePlus Nord 20 SE has appeared on AliExpress, and this basically represents the launch of this ...
- Lennox Vs. Trane Vs. Carrier: Which Is Best For You?
Choosing the best HVAC system for your home isn’t always easy. Comparing the best HVAC companies can be challenging with so many excellent brands in the market. Homeowners value features differently ...