A revealing study from The Lancet, published last week, revealed previously unknown details of the first case of person-to-person transmission of SARS-CoV-2 — the cause of COVID-19 — in the United States.
In this case, a woman who had recently traveled to China transmitted the infection to her husband, following prolonged, unprotected exposure between the two. Her husband had not joined her in China. The woman had been symptomatic, but infected only her husband — active monitoring was conducted of 372 contacts of both husband and wife, but no further transmission was found.
“This report suggests that person-to-person transmission of SARS-CoV-2 might be most likely to occur through unprotected, prolonged exposure to an individual with symptomatic COVID-19,” said Dr. Jennifer Layden, chief medical officer of the Chicago Department of Public Health and research co-lead. “Our experience of limited transmission of SARS-CoV-2 differs from Wuhan where transmission has been reported to occur across the wider community and among healthcare professionals, and from experiences of other similar coronaviruses. Nevertheless, healthcare facilities should rapidly triage and isolate individuals suspected of having COVID-19, and notify infection prevention services and local health departments for support in testing, management, and containment efforts.”
The case was logged back in January, when Illinois reported it as its first lab-confirmed case and, consequently, when the husband became the first case of secondary transmission in the United States. She had experienced six days of mild fever, fatigue, and cough before being initially hospitalized with pneumonia and, later, diagnosed with SARS-CoV-2. Her husband made it another eight days before being admitted due to shortness of breath and coughing up blood.
The new study from the Lancet detailed the assessment and monitoring of the individuals potentially exposed by the pair, charting data through both clinical and laboratory settings. Those traced included 152 community contacts and 195 healthcare professionals, along with 32 asymptomatic healthcare personnel contacts. All underwent symptom monitoring for 14 days following their last exposure.
During monitoring, 43 contacts did develop fever, cough, or shortness of breath and were promptly isolated and tested, but neither they nor the asymptomatic healthcare professionals tested positive for SARS-CoV-2. Both initial patients also recovered and were discharged into home isolation, which lasted 33 days after the woman had returned from Wuhan, China.