The latest case of Covid-19 community transmission has raised questions about the restrictions for staff at managed isolation and quarantine facilities.
But a nurses union spokesman and infectious diseases expert say the rules could not realistically be any tougher.
A health worker at the Sudima Christchurch Airport hotel tested positive for the virus on Monday sparking fears of more community transmission. Since then a colleague, who was a close contact of the person, has also tested positive.
A managed isolation and quarantine spokesperson said all workers followed strict infection prevention controls developed by the Ministry of Health to manage the risks of spreading Covid-19.
Staff working in the facilities were encouraged to change into work clothes when they arrived at work and take them off before leaving for the day, the spokesperson said.
"When staff return home they are encouraged to leave shoes outside or in a specific area, wash their work clothes and refrain from hugging loved ones until after they have washed and dried hands and arms, or taken a shower."
They were also advised to use hand sanitiser when leaving and keep their phones and other personal belongings in staff areas.
Rules for New Zealand Defence Force staff working at the Sudima Christchurch Airport hotel were more strict when at Burnham Military Camp. Those staff were not allowed to eat in the mess hall, go to the gym, go to a bar or congregate with other groups in Burnham.
Barrack accommodation has been made available to any Defence Force staff who preferred not to return home while working in managed isolation facilities. Two Burnham personnel have taken up the offer.
The spokesperson said Managed Isolation and Quarantine continued to work with the Ministry of Health around the implementation and adherence to infection prevention control protocols.
Nurses Society of New Zealand director David Wills said staff at the facilities were taking all possible precautions to avoid catching and spreading the virus.
He said it was not "realistic" for nurses working in isolation facilities to be expected not to have any engagement with people outside of work for the months or even years they remained in the job.
"This is a very, very contagious virus. Even with the strictest protocols some cross-infection and occupational transmission can occur," he said. "Nurses that are working in those facilities are very committed to having best practise.
"They have their own families to consider and they are not wanting to take that infection home or spread it to the whole community."
He said the most important restriction to stop the spread was that nurses working in the facilities were no longer allowed to work anywhere else.
Wills said nurses at the facilities were hyper aware of the symptoms and the need to isolate and get tested at the first sign of any sickness.
They were also subject to daily health checks and weekly Covid-19 tests, he said.
The Ministry of Health's website stipulates that all staff working in or transporting people to quarantine facilities must be tested every week while those working in or transporting people to managed isolation facilities should be tested every fortnight.
Infectious diseases expert Professor Michael Baker said imposing restrictions on workers' activities outside of work would be a very big ask for very little benefit.
"Adding more burdensome restrictions may make it harder to recruit and retain people," he said.
Rather, he said the emphasis should be on making sure protocols were followed at work and making sure workers self-quarantined and got tested as soon as any signs of the illness appeared.
He believed the best method of preventing community transmission was reducing the number of people entering the country with the illness to start with by requiring self-isolation and testing before people boarded a New Zealand-bound aeroplane from high risk countries.