Nearly six in 10 new COVID-19 infections are spread by people who show no symptoms of the virus, according to a new study.
The Centers for Disease Control and Prevention (CDC) study found that asymptomatic people made up about 24% of all transmissions. Meanwhile, pre-symptomatic individuals, those who have contracted the virus but do not yet have symptoms, accounted for 35% of new cases.
“In the absence of effective and widespread use of therapeutics or vaccines that can shorten or eliminate infectivity, successful control of SARS-CoV-2 cannot rely solely on identifying and isolating symptomatic cases; even if implemented effectively, this strategy would be insufficient,” the CDC researchers wrote in their study. “These findings suggest that effective control also requires reducing the risk of transmission from people with infection who do not have symptoms.”
Jay Butler, CDC deputy director for infectious diseases and a lead author of the study, said the study findings support public health guidelines that call for