A woman who traveled from China to Illinois in mid-January likely transmitted novel coronavirus to her husband through “prolonged, unprotected contact,” according to research released Thursday.
None of more than 300 people who came into contact with the two patients after they showed symptoms, however, developed symptoms of their own.
The findings, published in the medical journal The Lancet, detail the first known transmission of novel coronavirus in the United States, and suggest that the virus may transmit most easily through extended contact with infected people, not brief or casual exposures.
Dr. Jennifer Layden, the chief medical officer of the Chicago Department of Public Health, who co-led the research, stressed that health care providers should still “rapidly triage and isolate individuals suspected of having [the virus]” and notify local health departments.
That’s because, according to the study, “infection control measures within the hospital setting and an aggressive public health response” to these first cases might have prevented widespread coronavirus exposure. And it’s possible that other patients — those with more severe illness, for example — may transmit the virus more easily.
The researchers cautioned that their findings are preliminary and based on a single transmission event, which might not represent the population at large.
The study had other limitations, too. Because they relied on memories to reconstruct people’s movements, investigators might not have identified everybody who came into contact with the coronavirus patients.