International fishing crew sharing rooms and walking through corridors to go smoke outside is what led to two managed isolation staff contracting Covid-19, a new report has found.
Two healthcare workers at The Sudima Hotel in Christchurch contracted the virus from Russian and Ukrainian fishing crew who were isolating in November last year.
Canterbury District Health Board clinicians working at managed isolation facilities wrote a report documenting their experience for the Ministry of Health.
It found that prior to getting their first test results back, the crew were able to move back and forth through corridors to out go out to the smoking area.
It said during the first 2-3 days the fishing crew cohort were a challenging group of guests to manage in isolation as only three of the 235 guests spoke English, and two thirds of them were chain smokers who went out to smoke up to four times an hour.
"Compliance with requests to physically distance from other crew was patchy and in the first couple of days there was frequent exchanges of cigarettes, lighters, cell phones etc," the report said.
Report co-author, clinical director of infection prevention and control Dr Josh Freeman, said that was likely how the two staff caught the virus.
"In a hotel environment with poor ventilation in corridors, these factors all added up to being conducive to the inhalation of Covid-19 aerosols (extremely small microdroplets)," Freeman said.
"It's believed these identified risks led to two health staff contracting Covid-19 at work. Both staff became infected despite exemplary adherence to the PPE recommendations and infection prevention protocols that were in place at the time."
Another risk identified in the report was the fact the crew were sharing rooms - with two people in each room.
Another co-author Dr Anna Stevenson said as a result of the two staff testing positive, the CDHB worked closely with MIQ staff to introduce changes to the way the second group of fishing crew - which arrived earlier this month - were managed.
"Many changes were introduced immediately and we're happy to report that the stay of the second group of mariners, has been conducted with no issues arising," Stevenson said.
"They each had their own room. We identified those who smoked and ensured they had rooms with balconies and opening windows to ensure fresh air-flow, and to eliminate the need for these guests so have to move through the corridors to a smoking area outside."