A worker at a Christchurch managed isolation facility is the second staffer to become infected with Covid on the job in recent months and the garden city's second community outbreak since April.
The latest case is a staff member working in the Christchurch managed isolation facility, the Sudima Christchurch Airport, where a large group of international mariners have been staying.
The hotel is currently a Covid hotspot, with 31 seaman falling ill with the virus in the past fortnight. Even as late as yesterday the Ministry of Health reported a new case from the group on the eve of their scheduled quarantined stay.
The ministry has revealed the unidentified sick worker had developed symptoms for Covid-19 on Saturday and sought a further test on Sunday.
Sudima management last night confirmed the worker was not on the hotel payroll, but linked to an organisation running the managed isolation facility.
A Countdown supermarket in the city had since been deep cleaned and a school community was put on alert after a Cashmere High School student was identified as a close contact to the infected worker.
The startling development comes just two days after the cluster known as the Christchurch rubbish bin infection was closed.
That cluster began with the report on September 19 of a person who developed symptoms and was tested after finishing 14 days in managed isolation and returning two negative tests on days three and 12.
At the time health officials said an extensive inquiry had revealed it had come from the hotel where the infected person was isolating when they returned to New Zealand.
"As a result of an investigation within the managed isolation facility, the most likely source of infection was thought to be as a result of transfer of the infection via a rubbish bin with a lid shared with their neighbour who had developed the infection between the two tests in the facility," the ministry said.
"There are seven cases linked to the cluster - six announced as cases in the community (on September 19, 20 and 23) and the seventh (September 9) detected while still in managed isolation, but subsequently linked to the other six cases.
"Lessons from this cluster have resulted in changes being made, including informing our ongoing auditing and strengthening of our managed isolation procedures and processes."
This followed an earlier infection of where a healthcare worker at Auckland's Jet Park Hotel tested positive for Covid-19 on September 12.
A nurse was tested as part of routine testing for border staff and returned a positive result.
Five household contacts connected to the health worker went into isolation at their home.
Hospital-grade cleaning of medical and operational staff rooms was carried out using a Bioquell machine, which sanitised the spaces with hydrogen peroxide vapour.
At the time the person was the first Jet Park worker to test positive in the five-and-a-half months that the facility had been operational.
Director general of health Ashley Bloomfield said the nurse's case had been epidemiologically linked to a person being quarantined at the hotel and needed treatment before being hospitalised.
"The healthcare worker went into their room to provide care and assess them ahead of hospitalisation," he said.
"A review is under way at this very point and time to have a good look as to what happened and the circumstances to see if there are any lessons to be learned, any changes to protocols."
A month earlier, a maintenance worker at an Auckland managed isolation facility contracted Covid-19 from a guest, an investigation concluded likely came from using the same lift shortly after an infected returnee travelled in the same space a few minutes earlier.
The maintenance worker tested positive to Covid-19 on August 13, but his strain of the virus was found to be different to that involved in the large Auckland August cluster that forced the city into a two-week level-3 lockdown.
Instead, it matched the strain of a resident at the Rydges hotel - a woman who flew in from the United States before testing positive for Covid-19 and then being transferred a quarantine facility.
Bloomfield later said investigations had revealed the worker used a lift "very shortly" after the Covid-positive woman from the US used it.
He said if the worker had been infected in the lift, it would most likely have been from a contaminated surface rather than droplets circulating in the air.
The worker had been in the lift only a "matter of minutes" after the woman, data from swipe cards showed, Bloomfield said.