Earlier on Friday the Institute of Environmental Science and Research - ESR - reported there had been a positive Covid-19 test result detected from a wastewater sample in New Plymouth.
A follow-up sample, taken yesterday, returned a second positive result last night.
"Based on previous incidences, it is most likely that the two positive wastewater results are due to recently recovered cases continuing to shed the virus," says a Ministry of Health spokesperson.
The Ministry of Health is investigating whether any recovered cases who live in the New Plymouth area have recently left a managed isolation facility.
"Additionally, it is also possible that other recently recovered cases from elsewhere in the country could have travelled to New Plymouth," says a Ministry of Health spokesperson.
"ESR consider a single recovered person shedding the virus may be detected in wastewater.
"While the mariners aboard the Playa Zahara and Viking Bay vessels recently docked at Port Taranaki, in New Plymouth, the dates of their brief visits, and the activity of the crew, do not appear to be a factor in these wastewater detections."
Additional testing is being carried out for a small number of port workers and nurses, who have been in possible contact with the mariners. The nurses have previously been tested for COVID-19 and returned negative test results.
As an additional precautionary measure, and to help rule out possible undetected COVID-19 infection, the Ministry is encouraging anyone with symptoms, especially if they are in the New Plymouth area, to get tested. Additional testing capacity is being stood up in New Plymouth to support potential demand.
This advice also applies to recent visitors to the New Plymouth area.
Anyone with symptoms consistent with COVID-19 should call Healthline (0800 358 5453) for advice on getting a test.
For a list of all testing locations nationwide visit the Healthpoint website.
"We are closely monitoring this situation and additional public health advice will be provided if, and when, required," says a Ministry of Health spokesperson.
ESR undertakes regular wastewater testing across the country, as an additional surveillance tool in the fight against COVID-19.
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