Most people who were likely infected with the Omicron variant of SARS-CoV-2, the virus that causes Covid-19, they did not know they had the virusaccording to a new study from Cedars-Sinai researchers, which is published in “JAMA Network Open.”
“More than one in two people who were infected with Omicron didn’t know they had it,” says Susan Cheng, director of the Institute for Research on Healthy Aging in the Department of Cardiology at the Smidt Heart Institute at Cedars-Sinai and senior author. of the studio.
Previous studies have estimated that at least 25% and possibly as many as 80% of people infected with SARS-CoV-2 may not experience symptoms. Compared to other SARS-CoV-2 variants, the Omicron variant is associated with generally less severe symptoms that may include fatigue, cough, headache, sore throat, or runny nose.
“The findings of our study add to the evidence that undiagnosed infections can increase transmission of the virus. Low awareness of the infection likely contributed to Omicron’s rapid spread,” said Sandy Y. Joung, a Cedars-Sinai researcher and first author of the study.
As part of research into the effects of Covid-19 and the impact of vaccines, researchers began collecting blood samples from healthcare workers more than two years ago. In the fall of 2021, just before the start of the Omicron variant surge, researchers were able to expand enrollment to include patients.
Among the health workers and patients who participated in the investigation, the researchers identified 2,479 people who had contributed blood samples just before or after the start of the Omicron wave. Of these, they identified 210 people who were likely infected with the Omicron variant based on new positive levels of SARS-CoV-2 antibodies in their blood.
They then invited study participants to provide health status updates through surveys and interviews. Only 44% of study participants with newly positive SARS-CoV-2 antibodies knew they were infected with the virus. Most (56%) he was unaware of any recent Covid-19 infection. Of the study participants who were unaware, only 10% reported having recent symptoms that they attributed to a common cold or other type of infection.
Further studies involving larger numbers of people from various ethnicities and communities are needed to learn what specific factors are associated with a lack of awareness of infections, according to the researchers.
“We hope that people will read these findings and think, ‘I was just in a meeting where someone tested positive,’ or ‘I’m starting to feel a little sick.’ Maybe I should get a quick test.’ The better we understand our own risks, the better we are at protecting the health of the public and ourselves,” says Cheng.