ESR’s expansion of its wastewater testing in response to the recent outbreak of COVID-19 has seen samples collected from
148 locations covering an estimated 3.8 million people, and 95 percent of the New Zealand population connected to
reticulated wastewater systems.
Dr Joanne Hewitt, Senior Scientist and project co-lead at ESR said there were no unexpected detections to report based
on the testing from 98 locations in the North Island and 50 locations in South Island over the past two weeks.
“The team in ESR’s Porirua laboratory and those helping with sampling and transportation around Aotearoa have pulled out
all the stops to ensure there is unprecedented coverage of wastewater for testing.
“While the latest results continue to detect SARS-CoV-2 (that causes COVID-19) in the Auckland region, there have been
no unexpected detections around New Zealand. This includes from 26 sampling locations in Northland.”
Increased sampling in Northland took place as soon as possible following notification of the first community cases in
Auckland. Over the past two weeks, samples have been taken from small populations of just over 100 to much larger areas
such as Whangārei. Locations included Kerikeri, Dargaville, Hāruru, Hihi, Kaikohe, Kaitaia, Paihia, Rawene, Ruakaka and
Russell. However, it is important to remember that wastewater testing doesn’t capture people who are on septic tanks.
“While we believe that it is possible to identify the virus from potentially just a single infected person, the
likelihood of detection becomes much higher, the more cases in a community there are. So, while the absence of the virus
in wastewater doesn’t guarantee that there isn’t someone potentially infectious present, but it does suggest that there
aren’t lots of infected people.
“It is important to remember that wastewater sampling is just one part of New Zealand’s response to COVID-19. Community
testing, genome sequencing and the actions of all of us to follow public health guidelines remains crucial,” said Dr
Hewitt.