Don't Want To Catch Omicron? Researchers Say Open a Window

By Justin Hu (he/him)

An infectious disease researcher says better ventilation is key to slowing Omicron’s spread as health officials believe the beginning of semester has turned out to be a “nationwide super-spreader event” in uni halls.

Otago University public health researcher Julie Bennett told Debate that universities should improve indoor ventilation if air quality testing shows that current ventilation is poor.

She also says that poor ventilation is playing a key role in how people are continuing to catch the virus. In the past year, Bennett says the scientific community has settled on newer research that shows Covid-19 likely spreads primarily through the air and much less likely through other methods like on surfaces.

“At the very beginning, people were concerned the virus was spread through really close contact with touching and coughing - which it is,” she says.

“But as we’ve gone along, we know now that it's actually spread through really small aerosols.”

Infectious liquid aerosols can be expelled from a person’s mouth or nose and Bennett says they could linger around in a room for hours. The public health researcher says seeking out fresh air when spending time with others is a simple step to reduce your chances of catching Covid – alongside mask-wearing.

“You want to have as many doors and windows open as you can, or being outside if that's possible – essentially you want to have as much fresh air around you as possible,” she says.

“People initially heard at the beginning of the pandemic, and when we didn't know as much, to clean your hands etcetera, and so it took time for people to get their heads around … that it's actually airborne, [which is] why masks are so important too.”

The warning for people to recognise the role indoor fresh air plays in the spread of Covid comes as New Zealand is in the thick of its Omicron wave – which is hitting young people and students hard.

By early March, people who were under 30 made up for over half of all new reported Covid-19 cases. With large outbreaks at several university residence halls, Director- General of Health Ashley Bloomfield has referred to the new uni semester as a "nationwide super-spreader event".

At Victoria University in Wellington, there are over 600 cases of Covid-19 in halls of residence. With 2,500 residents in total, that means over a quarter of all residents have tested positive.

Vice-Chancellor Derek McCormack told the AUT Council in its February meeting that the university was aware there had been positive cases in its affiliated student accommodation.

Speaking to Debate, Bennett says universities should use carbon dioxide as a proxy to test the ventilation of high-capacity rooms and other spaces on campus where students gather.

“In something like a lecture theatre, you could have carbon dioxide monitors, which is what they are starting to do in schools, and the recommended level is that it needs to be below 800 parts per million and that's an indication that the ventilation in the room is doing what it should. And you know that it will be a safer environment to be in,” she said.

“If it goes above that, it's not good and something needs to change.” The public health researcher said larger-capacity environments, like classrooms, should have mechanical ventilation, which would bring outdoor air inside and dilute the quantity of any particles from an infected person.

In a statement, AUT spokesperson Alison Sykora says the university had considered indoor ventilation as part of its response to Covid.

“The majority of our buildings have mechanical ventilation systems which deliver fresh air at levels greater than World Health Organization recommendations,” she says.

“The few buildings that don’t have mechanical ventilation are generally occupied at low levels and have opening windows which the occupants can control.”

Meanwhile, Bennett said other measures would be needed if air quality testing showed a room couldn’t be sufficiently ventilated mechanically or by opening windows.

“There could be behavioural things you can do, like have fewer people in the room, or have people leave the room every hour and let the room try to refresh itself.”

She added that the use of high-quality N95 or equivalent masks would further help slow the spread. Bennett said including booster vaccinations in vaccination passes would also help make a more safer environment.

Sykora says the university had recently installed new systems to improve its provision of fresh air and that it was following Government guidelines on masking and distancing.

“Some of our more modern buildings have UV systems and we have recently fitted more of these systems.”

At AUT, there had already been over two dozen exposure events reported across the university’s campuses before semester one had even begun.

Though under phase three of the Government's Omicron response plan, close contacts at these exposure events, or any others on campus, will not need to isolate if they don’t have symptoms.