A new study of younger adults in the U.S. military found nearly a fifth of individuals with COVID-19 are asymptomatic and reinforced the importance of social distancing measures, according to the CDC's Morbidity and Mortality Weekly Report published June 9.
The U.S. Navy and CDC investigated an outbreak on the aircraft carrier USS Theodore Roosevelt from April 20-24, analyzing findings from a convenience sample of 382 service members. Among the respondents, 75.7 percent were male; 58.4 percent were non-Hispanic white; 7.3 percent reported a history of asthma, hypertension, diabetes or immunosuppression; and the median age was 30 years.
Five report takeaways:
1. In total, 60 percent of respondents had reactive antibodies indicating exposure to the coronavirus, and 59 percent of those also had neutralizing antibodies, a promising indicator of at least short-term immunity.
2. Nearly a fifth of infected participants were asymptomatic. Among 238 participants with previous or current infection, 81.5 percent reported one or more symptoms, 18.5 percent were asymptomatic and 0.8 percent (two individuals) were hospitalized for COVID-19.
3. The prevalence of previous or current infection was higher among men than women but did not differ significantly by age, race, ethnicity or medical history.
4. About 56 percent of respondents wearing face coverings reported infection, compared to 80.8 percent who did not wear one. Respondents who avoided common areas reported a 53.8 percent infection rate, versus 67.5 percent, while those who said they followed social distancing measures had a 54.7 percent infection rate, versus 70 percent for those who didn't socially distance.
5. Among 284 symptomatic participants, loss of taste or smell were the symptoms most strongly associated with previous or current infection, followed by fever, chills and muscle aches.