An Auckland hospital where staff spoke out about transmission concerns about treating both Covid-19 patients and people on different wards has changed its protocols.
Waitematā District Health Board is also urgently investigating how three nurses at Waitakere Hospital were infected with the coronavirus leading to 57 staff being temporarily stood down.
And a nursing union says, because of the blunder, patients have been subjected to unnecessary stress and unpleasant tests.
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Last week, three nurses at Waitakere Hospital tested positive for Covid-19 after working with patients transferred from the St Margaret's residential aged care home where there was an outbreak.
More than 50 staff were temporarily stood down and after contact-tracing 37 are being treated as close contacts and are in isolation as a precaution. More than 140 staff were tested.
The hospital's protocol meant nurses who'd treated the coronavirus patients could work on different wards on subsequent shifts, providing "appropriate precautions" were taken.
Staff have since spoken out about their concerns and the NZ Nurses' Organisation said the health boards protocols weren't good enough.
An urgent review into the source of the staff members' infections was launched at the weekend and the results will be released at the end of next week.
The Waitematā DHB said its policy fully complied with its advisory group's guidance on staffing but had changed its procedures in light of concerns and was changing its rosters.
It was now seeking to have staff work in "bubbles" to ensure those who work with Covid-19 patients didn't work on other wards on subsequent days.
NZ Nurses' Organisation kaiwhakahaere Keri Nuku said this policy was already in place in other district health boards which had clusters break out.
But Waitakere Hospital clearly hadn't taken that approach and because of that patients had been subjected to unnecessary tests, which could be very unpleasant, and stressful, she said.
"In this situation, it was avoidable."
The NZ Nurses' Organisation is part of the review into the nurses' infections, along with the Director of Nursing and Midwifery at Waikato DHB.
"What we've got to see is the learnings that we take from this external investigation are implemented so this type of thing does not happen tomorrow, in a week's time or in two months' time," Nuku said.
She didn't think there was a need for the Ministry of Health to issue specific guidance on staffing as there was already clear expectations around health and safety and PPE use.
"They should be responsible for something that's happening in their regions. It shouldn't have to be something that's micro-managed by the Ministry.
"But certainly DHBs have to be accountable back to the Ministry."
Director-General of Health Ashley Bloomfield said the Waitematā DHB relied on the advice of its clinicians' who had experience "day in, day out" in its hospitals.
"And I would imagine that - like me - they would consider what would be paramount would be ensuring that staff and other patients in the hospital were kept safe."