Today the ministry reported that four wastewater testing samples — three from a site linked to Papatoetoe and one from a wider wastewater collection point, which includes Papatoetoe — last night returned negative results for Covid detection.
This followed a weak positive test result detected on Friday in routine wastewater sampling at the site linked to Papatoetoe, which has been assessed as not posing a risk to the community.
The ministry said the most likely explanation for the weak positive detection was continued shedding of the virus from those who had recovered from covid in the February cluster who had returned home from the Auckland quarantine facility.
"We know that people who have recently had Covid-19 may continue to shed fragments of the virus for some weeks after they have recovered, without being infectious to others. Wastewater sampling can detect these fragments, which are not infectious and their presence is not considered a risk to the community," said the ministry.
This was supported by results from geospatial mapping linking the homes and residential addresses of the individuals to the catchment area where the sample was taken, said the ministry. The new negative wastewater testing results also provided good evidence to support this.
"The recovered cases are no longer infectious and there is no evidence that the wastewater is infectious," said the ministry.
The health ministry also sounded a word of warning about the low number of tests being carried out in the community. On Monday, 2,822 tests were processed.
"It's important testing levels in the community remain high so we continue to have confidence in our surveillance and detection," said the ministry.
The ministry said there were more than 2,753,053 registered users of the covid app, with an increase of more than 38,000 users in the past fortnight. There had been 1,103,685 poster scans in the last 24 hours alone.
"It's great to see ongoing good use of the NZ Covid Tracer app and it's vitally important that Kiwis continue to do so. Please scan QR codes wherever you go and turn on Bluetooth tracing in the app dashboard if you haven't already done so."
New Zealand has enjoyed 15 days straight with no new community cases after 15 people were infected in February's Valentine's Day outbreak.
The last infection in the cluster to emerge was on February 28, with the person in Auckland's quarantine facility when it started spreading among their household.
Thanks to a week-long alert level 3 lockdown across Auckland, the cluster was limited to four Papatoetoe families.
There has since been a border-related covid case involving an Air New Zealand flight attendant but tests from three household close contacts and 14 cabin crew have returned negative.
One person is in hospital, but not requiring intensive care treatment.
Yesterday there were seven new positive cases of Covid-19 in managed isolation. All had arrived in the country between March 11-13 and all but one was detected on day 0 or 1 of routine testing.
One person who arrived from the Netherlands on March 11 tested positive on day 2 after developing Covid symptoms. They were currently in a managed isolation facility in Hamilton.
Health officials yesterday reported a marked increase in new users of the COVID Tracer app in the past fortnight with an additional 47,000 people registering.
"It's great to see ongoing good use of the NZ COVID Tracer app and it's vitally important that Kiwis continue to do so," said the Health Ministry.