CHRIS SKELTON/StuffMore than 10,000 Covid-19 tests have been processed in Canterbury since the emergence of community cases last Thursday. (File photo)An extra Covid-19 testing centre will open in east Christchurch for two days as health officials work to explain a positive wastewater sample from that area. The Ministry of Health announced on Tuesday there were no new cases of Covid-19 in the city. But questions remain over the cause of the Covid-positive wastewater result detected in samples taken from eastern suburbs. The result was collected on Friday. Director-general of health Dr Ashley Bloomfield said on Monday the result was “likely” caused by someone who recently left managed isolation and quarantine, but this is yet to be definitively confirmed. READ MORE:* No new Covid cases in Christchurch, questions remain on Tongan case and wastewater results* Covid-19: Unexplained east Christchurch wastewater result ‘likely’ a historical case* Covid-19: 162 new cases in Delta outbreak, alert level review for Auckland, Waikato Later that day a Ministry of Health spokesman said wastewater testing “is regarded as a signal of possible cases”. No update on the east Christchurch wastewater test was given in the ministry’s public statement on Tuesday, except to say that results from additional samples were expected on Wednesday.STUFFStuff visited Bishopdale Village Mall to see how Cantabrians are feeling about the new cases of Covid-19 in Christchurch. Stuff has approached the ministry for further comment. Following the wastewater detection, a pop-up Covid-19 testing centre will open in east Christchurch at the New Brighton Club. It will run on Wednesday and Thursday this week, between 10am and 4pm, and will offer drive-through or walk-in tests. “This provides another convenient testing option for those in Christchurch’s eastern suburbs, following the wastewater detection on that side of the city,” Canterbury District Health Board’s emergency co-ordination centre controller, Tracey Maisey, said. “We want to make this as easy as possible.” Maisey said it was important any Cantabrians with Covid-19 symptoms get a test, “no matter how mild”. It is possible the wastewater result was caused by a person who had Covid-19 in the past few weeks or someone who is currently infectious. The result does not show which scenario is more likely. It also does not indicate how many people have – or have had – Covid-19. Meanwhile, health officials are continuing to look at whether the person who tested positive for Covid-19 in Tonga after flying there from Christchurch on Wednesday is actually a historical case.CHRIS SKELTON/StuffQueues at a Covid-19 testing station in Orchard Rd, near Christchurch Airport, stretched about one kilometre last Thursday morning after news of two new community cases in the city. Four New Zealand-based household contacts of the case have tested negative. The person, who is fully vaccinated, is understood to be a young missionary of the Church of Jesus Christ of Latter-Day Saints who arrived in New Zealand from South Africa in early September. They completed a stay in an Auckland MIQ facility before travelling to Christchurch. Their subsequent flight from Christchurch to Tonga was a repatriation flight. Experts have previously said both the positive wastewater test and the unexplained origin of the Tonga case could be a sign of undetected community transmission, but health officials do not think that is likely and say the risk to the public from both cases is low. Christchurch has not had a new community case of Covid-19 since Friday. One case reported on Saturday has been reclassified as a historical infection. There are presently only four community cases linked to the city. More than 10,000 Covid-19 tests have been processed in Canterbury since the first two community cases were confirmed on Thursday. There were 4345 Covid-19 vaccinations in Canterbury on Monday – 1170 first doses, 3160 second doses and 15 third doses for immunocompromised people. By the end of Monday, 91.4 per cent of the eligible population living in the CDHB area had received their first dose while 74.5 per cent were fully vaccinated. About 78,000 people still need to get their second jab for the region’s population to become 90 per cent fully immunised.