Atypical COVID-19: Preventing transmission from unexpected cases

Transmission most likely occurs via droplets from infected individuals with respiratory symptoms, but it remains unclear whether SARS-CoV-2 is just as transmissible by patients who do not have respiratory symptoms. Since January 23, 2020, the 1,600-bed Tan Tock Seng Hospital, co-located with the 330-bed National Centre for Infectious Diseases (NCID), has managed >9,000 COVID-19 patients.6 Contact tracing was immediately performed for every COVID-19 patient not managed at designated COVID-19 areas (fever zones) in the emergency department or clinic, or not pre-emptively admitted to an airborne infection isolation room (AIIR). [...]3 close patient contacts and a caregiver developed ARI symptoms, as well as another close patient contact whose chest x-ray showed worsening of air-space changes. [...]we have reported 5 patients not initially suspected with COVID-19 and thus not managed at COVID-19–designated areas or AIIRs. [...]19 symptomatic contacts and 48 asymptomatic staff contacts were tested for SARS-CoV-2; none were positive for the virus. Because the same vigilance for ARI patients cannot realistically be implemented for the smaller proportion of patients with atypical symptoms, the following measures are crucial for preventing nosocomial transmission of SARS-CoV-2: a robust hospital system with risk-based personal protective equipment, staff sickness surveillance,7 and rapid identification of COVID-19 patients with immediate contact tracing and management.