Zoono and SARS, page-570

https://medicalxpress.com/news/2020-03-person-to-person-transmission-coronavirus-usa.html

New research published in The Lancet, describes in detail the first locally-transmitted case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, in the USA
Person-to-person transmission of SARS-CoV-2 occurred between two people with prolonged, unprotected exposure while the first patient was symptomatic. Despite active monitoring and testing of 372 contacts of both cases, no further transmission was detected.

On December 25, 2019, the female patient travelled to Wuhan where she visited a hospitalised relative and other family members with undiagnosed respiratory illness. On her return to the USA on January 13, 2020, she experienced six days of mild fever, fatigue, and cough before being hospitalised with pneumonia and testing positive for SARS-CoV-2 (figure 1). Prior to hospitalisation she was living with her husband who has chronic obstructive pulmonary disease (COPD) and chronic cough. These conditions made it difficult to determine the timing of his symptom onset related to COVID-19. Eight days after his wife was admitted to hospital, the husband was also hospitalised with worsening shortness of breath and coughing up blood, and also tested positive for SARS-CoV-2Both patients recovered and were discharged to home isolation, which was lifted 33 days after the woman returned from Wuhan, following two negative tests for SARS-CoV-2 taken 24 hours apart.
"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", says Dr. Jennifer Layden, Chief Medical Officer of the Chicago Department of Public Health, USA, who co-led the research. "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."