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Posts misrepresent study examining household coronavirus transmission

December 28, 2020 GMT

CLAIM: University of Florida researchers found “no asymptomatic or presymptomatic spread of Covid” in a study published by the Journal of the American Medical Association.

AP’S ASSESSMENT: False. A spokesperson for the Journal of the American Medical Association network of publications denied publishing findings that SARS-CoV-2, the virus that causes COVID-19, does not spread without symptoms. University of Florida researchers who authored a recent study called the social media posts a “misrepresentation” of their findings.


THE FACTS: A recent scientific study is being misrepresented online leading to the spread of misinformation about COVID-19.

“University of Florida researchers have found no asymptomatic or presymptomatic spread of Covid. The study was published online by the Journal of the American Medical Association. This could change everything,” reads a false post that was shared on Dec. 27 and had amassed more than 35,000 retweets a day later. 

Social media users shared the false post to justify arguments that shutting down businesses and schools during the pandemic was unnecessary. One such post was shared more than 11,000 times on Facebook as of Monday.

A spokesperson for the network of journals published by the Journal of the American Medical Association confirmed to The Associated Press that no study with such conclusions had been published by the network.

“Numerous reports support transmission of SARS-CoV-2 by individuals who are asymptomatic,” Deanna Bellandi, media relations manager for JAMA Network wrote in an email. “Claims that any JAMA Network journal has published evidence to the contrary is incorrect and misleading.” 

The false claims follow the release of a study by a team of University of Florida researchers titled: “Household Transmission of SARS-CoV-2: A Systematic Review and Meta-analysis,” that was published on Dec. 14 on the website of JAMA Network Open, one of the journals in the JAMA network. 

The study consolidated and analyzed data from 54 previous studies about household spread of SARS-CoV-2, and found rates of transmission to other household members was higher if the infected person had symptoms rather than was asymptomatic. The analysis also found transmission was higher between adults rather than children, and between spouses rather than other family contacts. 


The study did not conclude there is no asymptomatic or presymptomatic spread of COVID-19 as social media users claim it does.

“No, no we didn’t say that,” said Natalie E. Dean, a co-author of the study and a University of Florida assistant professor of biostatistics “This is a misinterpretation of our message of our scientific findings and conclusions.”

Dean said it is important for the public to understand her study was only analyzing household studies and there is limited data at this point. She said “there does seem to be evidence that people who never have symptoms do appear to be less infectious,” but she said that does not mean that people without symptoms cannot transmit the virus that causes COVID-19.  

“Certainly we are seeing presymptomatic transmissions before they develop symptoms,” Dean said, a point that is also made clearly in the article text. She called presymptomatic transmission “an important feature of this virus” and said “our policies need to reflect that.”

People who are infected with COVID-19 but are not experiencing symptoms cannot know whether or not they will develop them. 

Dean noted that even if it is the case that people who have symptoms and are coughing are more infectious, someone without symptoms who may be less infectious could wind up spreading the virus more if they are continuing to interact with other people. 

The published study says “important questions remain” about household spread, including how infectious asymptomatic, mildly ill and severely ill cases are. The conclusion reads: “The findings of this study suggest that households are and will continue to be important venues for transmission, even where community transmission is reduced.”


This is part of The Associated Press’ ongoing effort to fact-check misinformation that is shared widely online, including work with Facebook to identify and reduce the circulation of false stories on the platform.

Here’s more information on Facebook’s fact-checking program: