N.S. Health shares investigation update, lessons learned from COVID-19 outbreak at Halifax infirmary

Nova Scotia Health has released an update on their investigation into an outbreak of COVID-19 at the Queen Elizabeth II Health Sciences Centre’s infirmary site.

During the spring outbreak, 21 people in the affected unit tested positive for COVID-19 and three people died because of the disease. An additional three people also died with COVID-19, but “other health factors were responsible for their deaths,” according to a release from Nova Scotia Health.

The outbreak was declared on May 12, 2021, after a second inpatient in a non-COVID-19 unit at the QEII tested positive for the virus. The first patient who tested positive initially tested negative at the time of their admission a few days prior, although they were admitted with respiratory symptoms.

In the following two weeks, 19 other patients in the same unit would test positive. The last positive result was recorded on May 25 and the outbreak was declared over on June 22 when two incubation periods had passed with no new cases.

The hospital put “immediate outbreak measures” in place once the outbreak was declared, which included:

• Closing the unit to admissions and sending home patients who were ready for discharge.
• Transferring patients who tested positive to the COVID-19 unit.
• Putting patients remaining in the outbreak unit, along with any who had been transferred to other units and hospitals, on contact and droplet precautions.
• Keeping patients to their room/bedspace and having patients maintain physical distancing and masking when outside of their room/bedspace.
• Implementing facility-wide re-education “on the importance of not over-relying on a negative COVID-19 test to remove precautions on symptomatic patients.”
• Testing everyone in the facility, which did not reveal any additional cases outside of the outbreak unit.

The investigation into the cause of the outbreak was launched while the outbreak was still active, the release said. It included a review of patient charts, room placements, staffing assignments, staff testing for COVID-19, and molecular analysis of viruses that were isolated from patients and health-care workers.

“This information was analyzed to identify factors that contributed to the outbreak,” it said. “When the results of the molecular analysis returned in July, the infection prevention and control team was able to confirm hypotheses that were formed during the initial investigation.”

They found that of the 21 cases, two were community-acquired cases that were not linked to the outbreak and did not spread to other patients, and there were two patients whose typing of their COVID-19 strain could not be done for laboratory-related reasons.

The remaining 17 people who tested positive “all belonged to one of two groupings of genetically linked viruses,” the release said.

“In each of these two groupings, there was a patient who had been admitted with respiratory symptoms, but initially tested negative for COVID-19, and who was likely the source of infection for the other patients in the molecular grouping,” it said.

It said most of the patients in the unit were unvaccinated at the time of the outbreak and had at least one co-morbidity “that made them vulnerable to infection and severe illness from infection.”

As well, it said sharing a room with a patient who developed COVID-19 or with a patient who had “wandering behaviours” was a risk for infection during the outbreak.

Lessons learned

Nova Scotia Health included a list of lessons they “learned or relearned,” which included not relying on a negative test for COVID-19 for a reason to remove a symptomatic patient from contact and droplet precautions.

It also said shared rooms are a risk factor for infection transmission, and said all inpatient units should be “appropriately resourced to implement strategies to manage wandering patients that are commonly used in settings that care for persons with dementia and other conditions that impede infection prevention and control practices.”

As well, vaccination, use of masks and physical distancing remain critical measures to prevent the spread of COVID-19.

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It said Nova Scotia Health is implementing actions, which include:

• A province-wide re-education program and reinforcement of learned and relearned best practices for acute care facilities.
• A review of policies and inclusion of learned best practices of COVID-19 infection prevention and control, as well as patient care protocols.
• And recommendation for single-patient rooms as the standard for new or renovated hospital builds.

Nova Scotia Health said COVID-19 outbreaks have been common in health-care facilities like hospitals during the pandemic “and could continue to occur if preventative efforts do not remain at the forefront.”

“Infection prevention and control measures must remain at the centre of all we do in order to keep our patients, visitors, and health care workers safe,” the release said.

“We all have a role to play in these efforts and look to our patients and their families assisting us as we work to prevent the spread of infection in our facilities.”