Dr Malcolm McKellar's office, equipped with a forced air heat-exchange vent (ceiling top left) and a UVC unit on the wall above his desk, sterilising the room's warm expelled air

South Island cataract and refractive surgeon Dr Malcolm McKellar has gone the extra mile to avoid his patients or staff contracting Covid, installing high-efficiency particulate air (HEPA) filtration, germicidal UVC lighting units and extra ventilation at his Christchurch practice.

Together the equipment and fitting exceeded $13,000, said Dr McKellar, with annual maintenance costs of around $1,800. But the benefits extend beyond improving the safety of everyone in the practice, he said. He installed the forced-outside-air ventilation system after his portable CO₂ meter showed the CO₂ level in his room at the end of a busy clinic was 1,200ppm – more than 2.5 times higher than the level outdoors. “At that level we are aware the air is stuffy and cognitive function suffers. So this kills two birds with the one stone!” he said.

A standalone HEPA filter with inbuilt UV sterilising to the practice nurse's right

The investment makes good business sense, said Dr McKellar. “I really don’t understand why people think it’s not worth the effort. It’s a tax-deductible expense and if me or my staff are off sick it costs a lot of money.”

Although the UVC is relatively old technology, Dr McKellar said it rapidly inactivates tuberculosis, the measles virus and Covid, and poses no risk to skin or eyes when used near the ceiling. The forced-air, heat-exchange vent (pictured) works with the UVC unit, which shines a tight beam across the top 25cm of the room, sterilising the room's warm expelled air. The practice also encourages patients and whanau, including those who claim to have a mask exemption, to wear N95 masks, which are compulsory for staff. Plus it pays for staff members’ shingles vaccine, since Covid infection increases the risk of developing it, and Covid sick leave has been added to normal annual sick leave entitlements. “I want my staff to feel no shame in staying away and they can only return to work with a negative rapid antigen test, not at an arbitrary time,” said Dr McKellar.

On a personal level, Dr McKellar said pre-Covid he was always getting upper respiratory tract infections and flare ups of post-viral asthma. “I’ve now been well for three years. Even if Covid magically went away, I would still do all of this. The HEPA filtration also means my workplace is pollen and hayfever free – a real haven.”