Study: First known person-to-person transmission of COVID-19

Editor's Note

The first person-to person transmission of COVID-19 occurred between two people in Illinois with prolonged, unprotected exposure while Patient 1 was symptomatic, this study finds.

Patient 1, a woman in her 60s, returned from China in mid-January. One week later, she was admitted to the hospital with pneumonia and tested positive for COVID-19.

Patient 2, her husband, did not travel but had frequent close contact with his wife. He was admitted to the hospital 8 days later and tested positive for COVID-19.

A total of 372 contacts (152 community, 195 healthcare personnel) of both patients were identified and had active symptom monitoring. Of monitored contacts, 43 became persons under investigation. These 43, who were symptomatic, and 32 asymptomatic healthcare personnel, who were tested after their highest-risk exposure, all tested negative for COVID-19. No further transmissions were detected.

The data suggest that person-to-person transmission of COVID-19 is most likely to occur through unprotected, prolonged exposure to a patient with symptomatic COVID-19, the researchers say.