The wastewater of locations throughout Aotearoa New Zealand was tested over the week ending 22 January and highlighted new detections of the virus in Motueka, Napier, Hastings, Gisborne, Whangamata, Kawakawa Bay, Opononi and Kaitaia.
A positive detection in the wastewater indicates that at least one person has been shedding SARS-CoV-2 into the wastewater in the 24 hours before each sample was collected. Just as a negative finding does not necessarily guarantee an absence of COVID-19 in the community, it should be noted that a positive finding does not necessarily mean that active COVID-19 infections are present in the community.
A positive detection in the wastewater could also be due to a case in a managed isolation facility and/or a non-infectious historical case or a non-infectious recently recovered case who is still shedding low levels of SARS-CoV-2.
Read more here(external link).