Wielding the waste of the nation to combat COVID-19

Dr Joanne Hewitt, Science Leader at the Institute of Environmental Science and Research (ESR), reflects on her career as a virologist and the fundamental role she and her team played in New Zealand’s response to the COVID-19 pandemic in a new podcast from local producers PhD: Unpacked.

ESR and Dr Hewitt had been working with wastewater and viruses for years before COVID-19 came on the scene. So as soon as a new coronavirus started causing global concern in the summer of 2019-2020, Joanne and her team were already thinking ahead.

“Very quickly when we came back after the Christmas break, we were on alert,” Joanne told podcaster Thabi Sibanda in the episode.

“We knew something was happening, but we didn’t know what was going to happen. And we didn’t know if we could use wastewater at that time either.”

Once COVID-19 cases started being reported, ESR got hold of some wastewater samples from sites with known outbreaks.

“Surprisingly, we picked [the virus] up,” Joanne recalled. “That was a good day and I thought, yeah, it does work.”

The New Zealand Government set up the MBIE-administered COVID-19 Innovation Accelerator Fund in April 2020. This fund aimed to accelerate the deployment of innovative solutions in the response to COVID-19 and alleviate direct impacts of the virus threat.

Just over $2 million of this funding was invested in Joanne’s team at ESR to research the risks to public health and opportunities for surveillance in wastewater, something Joanne described as “invaluable”.

At the time, New Zealand was in a unique position globally as most cases were contained to a single quarantine facility, Jet Park Hotel in Auckland. Fortuitously for ESR, the wastewater coming from the hotel could be isolated for testing before it joined the network.

“Every single day for 4 months, we tested wastewater at the hotel and the interceptor downstream, which contained input from an additional 120,000 people. By doing this, we could calculate the sensitivity of wastewater surveillance as we knew exactly how many people we had there with the virus.”

As well as gaining valuable experience, the real-life experiment became a gamechanger for COVID-19 surveillance as it meant scientists understood its potential and its sensitivity. The testing could also precisely and reliably measure the amount of the virus shed in community wastewater, not just detect its presence.

The Government soon tasked ESR to roll out nationwide surveillance and provide a failsafe way to monitor the virus’ spread and prevalence.

“Wastewater surveillance doesn’t rely on people going to the doctors,” Joanne explained. “It doesn’t rely on people reporting their [COVID-19] tests. People don’t have to do anything at all.”

In the podcast, Joanne describes the manic early days to Thabi, when her team was haphazardly receiving 200+ samples a week, testing, analysing and reporting the results the same day, every day.

Despite all the headaches and relentless workload, the capability ESR developed would be paramount when Delta was detected in Auckland on 17 August 2021 after 100 days of no community transmission.

“We had to make sure that [the virus] was only in Auckland so measures could be put in place to contain it. […] We were mid-through our rollout of vaccines, so it was important to have good information on how far it had spread.”

Ironically, the best and most reliable information was what was being flushed down the loo.

Listen to the full podcast to learn more about Joanne’s experience leading the national wastewater surveillance response, the evolution and future of environmental virology, and even how online “COVID sleuths” are using publicly available information like ESR’s to identify new variants and ways the virus is moving around the world.

How did poo save New Zealand from Covid-19? - Dr Joanne Hewitt | S3:E7 with MBIE & ESR(external link) — YouTube