Why some COVID-19 infections may be free of symptoms but not free of harm

Eric Topol was worried when he first saw images of the lungs of people who had been infected with COVID-19 aboard the Diamond Princess, a cruise ship that was quarantined off the coast of Japan in the earliest weeks of the pandemic. A study of 104 passengers found that 76 of them had COVID but were asymptomatic. Of that group, CT scans showed that 54 percent had lung abnormalities—patchy grey spots known as ground glass opacities that signal fluid build-up in the lungs. These CT scans were “disturbing,” wrote Topol, founder and director of the Scripps Research Translational Institute, with co-author Daniel Oran in a narrative review of asymptomatic disease published in the Annals of Internal Medicine. “If confirmed, this finding suggests that the absence of symptoms might not necessarily mean the absence of harm.”