Wednesday, May. 12, 2021
Do a small number of patients carry high loads of the coronavirus even if they don’t show any symptoms?
Multiple studies have found that people showing no COVID-19 symptoms can carry as much of a transmissible load of the coronavirus as evidently ill patients. Since the load, or amount of virus present in an infected person’s body, is the biggest factor in transmitting the disease, this adds to the challenge of trying to track and manage the spread of COVID-19.
Studies published in leading medical journals in the U.S. and the U.K. have found viral presence to be similar whether infected people are symptomatic or asymptomatic. A third study found that “viral loads of asymptomatic patients were…significantly higher.”
A 2021 study noted that high viral loads are concentrated among a very small number of infected people, both symptomatic and asymptomatic, for reasons not yet understood. “Just 2% of infected individuals carry 90% of the virions circulating within communities,” it found.
This fact brief is responsive to conversations such as this one.
Sources
- News Medical Viral load the main driver of SARS-CoV-2 transmission
- JAMA Network Clinical course and molecular viral shedding among asymptomatic and symptomatic patients with SARS-CoV-2 infection in a community treatment center in South Korea
- The BMJ Upper respiratory viral load in asymptomatic individuals and mildly symptomatic patients with SARS-CoV-2 infection
- Nature Public Health Emergency Collection Higher viral loads in asymptomatic COVID-19 patients might be the invisible part of the iceberg
- Proceedings of the National Academy of Sciences Just 2% of SARS-CoV-2−positive individuals carry 90% of the virus circulating in communities
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Fact briefs are bite-sized, well-sourced explanations that offer clear "yes" or "no" answers to questions, confusions, and unsupported claims circulating online. They rely on publicly available data and documents, often from the original source. Fact briefs are written and published by Gigafact contributor publications.
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Between 2020 and 2022, under close editorial supervision, Gigafact contracted a group of freelance writers and editors to test the concepts for fact briefs and provide inputs to our software development process. We call this effort Gigafact Foundry. Over the course of these two years, Gigafact Foundry writers published over 1500 fact briefs in response to claims they found online. Their important work forms the basis of Gigafact formats and editorial guidelines, and is available to the public on Gigafact.org. Readers should be aware that while there is still a lot of relevant information to be found, not all fact briefs produced by Gigafact Foundry reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date and need to be looked at with fresh eyes, don't hesitate to contact us at support@gigafact.org.
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