ALDEN WILLIAMS/StuffA person who tested positive for Covid-19 in Tonga after flying from Christchurch last Wednesday has returned a negative result following a second test. (File photo).A person who tested positive for Covid-19 in Tonga after flying from Christchurch has returned a negative result following a second test, Tongan media is reporting. Matangi Tonga said in an article on Wednesday that the person, referred to as “patient zero”, had tested negative for Covid-19 following a second test. Tonga Ministry of Health chief executive Dr Siale ‘Akau’ola told Matangi Tonga the person would be retested again on Friday. “[If it is] reaffirmed to be negative, then that is really good news.” He said a genomic study still needed to be done to check if the virus was the Delta variant. READ MORE:* Covid-19: No new cases in Christchurch, wastewater test results to be revealed Thursday* Extra Covid testing centre to open in east Christchurch after positive wastewater sample* Latest wastewater tests reveal no new traces of Covid-19 in ChristchurchSTUFFStuff visited Bishopdale Village Mall to see how Cantabrians are feeling about the new cases of Covid-19 in Christchurch. The person flew from Christchurch to Tonga last Wednesday after returning a negative pre-departure test. A test upon arrival in Tonga came back positive last Friday. A New Zealand Ministry of Health spokesman previously told Stuff household and work contacts of the case had all returned negative tests so far. The case had been in New Zealand for at least a week before flying out and the ministry said the risk to the New Zealand public was considered low. It was earlier reported that the person was a young missionary of the Church of Jesus Christ of Latter-day Saints who had been overseas and stayed in New Zealand for several weeks before flying to Tonga. Wastewater test results due Meanwhile, with no new cases of Covid-19 in Christchurch in recent days, the results of wastewater tests due on Thursday should explain how two positive samples of the virus were found in the city.ESR/SuppliedNew wastewater samples have been taken from 14 sites across Canterbury after two earlier wastewater samples came back positive for Covid-19. (File photo). One hundred new community cases of Covid-19 across the country – 97 in Auckland and three in Waikato – were confirmed by the Ministry of Health in a media statement released at 1pm on Wednesday. New wastewater samples had been taken from 14 sites across Canterbury after two earlier samples came back positive for Covid-19. One of those samples, collected from east Christchurch on Friday, still has no definite explanation. The other positive sample, from southern Christchurch, was put down to a known case living in the area. The ministry initially said the results would be released later on Wednesday afternoon, but when Stuff asked when exactly that would be, it said the results of the tests would now be released at 1pm on Thursday. No reason was given for the delay. It is possible for positive wastewater results to be caused by a person who had Covid-19 in the past few weeks or someone who is currently infectious. The sample results do not show which scenario is more likely. The results also do not indicate how many people have – or have had – Covid-19. Director-General of Health Dr Ashley Bloomfield said on Monday the unexplained east Christchurch wastewater was “likely” caused by someone who recently left managed isolation and quarantine. In response to that positive test, health officials set up an extra pop-up testing centre in east Christchurch. It will only open on Wednesday and Thursday from 10am to 4pm. It has been set up at the New Brighton Club and is doing drive-through and walk-in tests. East Christchurch has some of the city’s lowest vaccination rates. In the past week, more than 47,000 people in Canterbury got vaccinated, about 13,000 of which were first doses.CHRIS SKELTON/StuffAs of Thursday, 92 per cent of the eligible population living in the Canterbury health board area have had at least one dose of the vaccine, while 75 cent are fully vaccinated. (File photo). East Christchurch leaders, health providers and advocates are encouraged by the jump in Covid-19 vaccinations, which they say was likely spurred by the city’s recent community cases. As of Thursday, 92 per cent of the eligible population living in the Canterbury health board area have had at least one dose of the vaccine, while 75 cent are fully vaccinated. Just over 71,000 people still need to get their second jab for the region’s population to become 90 per cent fully immunised.