Public health expert Nick Wilson is calling on the government to introduce masks on flights - and says its current advice is outdated.
His call comes after the International Civil Aviation Organisation this week adopted a number of health measures to enable safe travel during the Covid-19 pandemic.
Aside from the use of masks, the recommendations include testing, distancing, screening, contact tracing, health declarations, and regular sanitation.
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The Ministry of Health said it was reviewing the guidance - and had some measures, such as declarations, screening and tracing, already in place.
University of Otago public health expert Professor Wilson said based on overseas evidence, wearing masks onboard aircraft made a lot of sense.
"The idea about requiring masks on flights is a very good one," he said.
"We have actually seen in literature some examples of Covid-19 spread on planes."
Some airlines around the world already require masks.
Wilson said research from Hong Kong showed that 99 per cent of people who went outside covered their faces - and despite its dense population, the city has had only four deaths from Covid-19.
He urged the Ministry of Health to update its advice on masks.
"There was some very poor advice I think provided by the ministry and it was partly based on the fear that we would run out of masks and there wouldn't be masks available for health workers," Wilson said.
"That is no longer a valid concern."
The Ministry of Health told RNZ in a statement that it was currently reviewing the guidelines by ICAO.
"The Ministry of Health is continuing to work closely with border stakeholders and the aviation sector to implement, review, and where necessary, strengthen border measures," the ministry said.
Aviation commentator Peter Clark said with New Zealand having gone two weeks without a single coronavirus case and with alert level one looming, ICAO's advice was not needed.
Wearing masks on long-haul flights would be a struggle, he said.
"It would be very hard sometimes to be wearing masks for 14-odd hours," he said.
"You have to eat, you have to blow your nose, you have to do things and it's only reducing the potential risk - it doesn't alleviate the risks."
Clark said the proposals should only affect countries with high density populations.
"Certain people may want to do these things and there are aspects of cleaning the aircraft - and that sort of thing is quite essential."
Wilson said people would wear masks on flights if they were required.
"People can hook up the masks for meal times and so on but pull them down afterwards, and with proper mask design it's very comfortable to... sleep," he said.
New Zealand must learn lessons in managing Covid-19 from countries, such as like Taiwan, which avoided a lockdown by using masks, digital technology and smart quarantining, Wilson said.