Long-term care staff inadvertently spread coronavirus as they traveled between an operator’s facilities in the early days of the first U.S. outbreak in King County, Washington, according to public health officials.

The illness, first detected in a resident in early February, eventually spread to 81 residents, 34 staff, and 14 visitors. Fully 23 had died by March 9, reported investigators with the Centers for Disease Control and Prevention.

Onsite visits and surveys uncovered the vulnerabilities that likely contributed to the quick escalation in cases. Factors included:

  • Staff members who worked while symptomatic
  • Staff members who worked in more than one facility
  • Inadequate familiarity and adherence to standard, droplet, and contact precautions and eye protection recommendations
  • Challenges to implementing infection control practices including inadequate supplies of personal protective equipment and other items (e.g., alcohol-based hand sanitizer)
  • Delayed recognition of cases due to low index of suspicion
  • Limited testing availability
  • Difficulty identifying persons with COVID-19 based on signs and symptoms alone.

“Limitations in effective infection control and prevention and staff members working in multiple facilities contributed to intra- and interfacility spread,” wrote Temet McMichael, Ph.D., and colleagues.

Long-term care facilities can take proactive steps to prevent a similar outbreak, the researchers concluded. These include: identifying potentially infected staff members; restricting visitation except in compassionate care situations; ensuring early recognition of potentially infected patients; and implementing appropriate infection control measures.

The study was publicly released by the CDC on Wednesday.