Investigation of nosocomial SARS-CoV-2 transmission from two patients to healthcare workers identifies close contact but not airborne transmission events.

OBJECTIVE: To describe the pattern of transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) during 2 nosocomial outbreaks of coronavirus disease 2019 (COVID-19) with regard to the possibility of airborne transmission. DESIGN: Contact investigations with active case finding were used to assess the pattern of spread from 2 COVID-19 index patients. SETTING: A community hospital and university medical center in the United States, in February and March, 2020, early in the COVID-19 pandemic. PATIENTS: Two index patients and 421 exposed healthcare workers. METHODS: Exposed healthcare workers (HCWs) were identified by analyzing the electronic medical record (EMR) and conducting active case finding in combination with structured interviews. Healthcare coworkers (HCWs) were tested for COVID-19 by obtaining oropharyngeal/nasopharyngeal specimens, and RT-PCR testing was used to detect SARS-CoV-2. RESULTS: Two separate index patients were admitted in February and March 2020, without initial suspicion for COVID-19 and without contact or droplet precautions in place; both patients underwent several aerosol-generating procedures in this context. In total, 421 HCWs were exposed in total, and the results of the case contact investigations identified 8 secondary infections in HCWs. In all 8 cases, the HCWs had close contact with the index patients without sufficient personal protective equipment. Importantly, despite multiple aerosol-generating procedures, there was no evidence of airborne transmission. CONCLUSION: These observations suggest that, at least in a healthcare setting, most SARS-CoV-2 transmission is likely to take place during close contact with infected patients through respiratory droplets, rather than by long-distance airborne transmission.

A Community-transmitted Case of Severe Acute Respiratory Distress Syndrome (SARS) Due to SARS-CoV-2 in the United States.

This is the first known community transmission case of the novel coronavirus disease (COVID-19) in the United States, with significant public health implications. Diagnosis of COVID-19 is currently confirmed with PCR based testing of appropriate respiratory samples. Given the absence of travel or known exposure history, this patient did not meet the criteria for testing according to CDC guidelines at the time of her presentation. Since this case, any patient with severe disease (eg, ARDS or pneumonia) requiring hospitalization without an explanatory diagnosis can be tested even if no clear source of exposure is identified. While influencing national health policies for revising screening criteria, this case also highlighted significant knowledge gaps in diagnosis and treatment and a desperate need for early, widespread, fast and cheap testing for COVID-19.