Scientists who analyzed viral loads for individuals tested through the University of Colorado at Boulder’s asymptomatic COVID-19 screening program found that “just two percent of infected individuals carry ninety percent of the virions circulating within communities, serving as viral ‘supercarriers’ and likely also superspreaders.”
The CU Boulder-based researchers also found that, regardless of symptomatic status, approximately 50 percent of individuals who test positive “seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated.”
An article summarizing their findings was published Monday in the Proceedings of the National Academy of Sciences. The lead author of the study is Qing Yang, of Boulder’s BioFrontiers Institute and the Department of Molecular, Cellular and Developmental Biology.
The data set used by the researchers was unique in that all infected individuals reported no symptoms of COVID-19 at the time of the saliva-based screening test and were therefore either asymptomatic or presymptomatic.
Notably, the researchers found that “the distribution of SARS-CoV-2 viral loads on our campus is indistinguishable from what has previously been observed in symptomatic and hospitalized individuals. Strikingly, these datasets demonstrate dramatic differences in viral levels between individuals, with a very small minority of the infected individuals harboring the vast majority of the infectious virions.”