Covid-19 is dividing Dunedin in two, the city's student quarter and the rest of town experiencing very different pandemics.

The central city WellSouth testing centre has been giving out 1000-plus test kits a day since Thursday, but the Te Kaika testing centre in Victoria Rd — a location which at previous weekends has had hundreds of people queuing up outside — was almost idle at the weekend.

Health authorities suspect that people in Dunedin's suburbs rushed to get rapid antigen tests (Rats) as soon as they became available and are still working their way through their supplies.

In the student areas, however, where cases are known to be rife and where more than 1000 university college residents have been confirmed as having become infected with Covid-19, demand for test kits remains strong.

"The Malcolm St site has provided 5000 [rapid antigen] tests total since Thursday," a WellSouth spokeswoman said.

"It has also continued to provide 20 to 30 PCR tests a day to healthcare workers, for pre-admission testing for anyone going into hospital, or when the swabbing clinicians on-site believe it is the clinically appropriate method of testing."

On the other side of town, at the Te Kaika testing site, the health provider's systems innovator Raewyn Nafatali said demand was markedly lower.

At the beginning of the current Covid wave there had been a lot of anxiety in the community, people being on high alert, but rapid testing had decreased that demand.

The DIY tests were good for staff and people visiting the site, as they meant shorter wait times in the drive-through, she said.

"Wait times for PCR tests used to be over an hour, but today a visitor would be lucky to wait 10 minutes to get seen."

Yesterday, Otago and Southland reported 444 cases of Covid-19 from a national total of 15,161.

On Saturday, the regions reported 558 cases out of the national figure of 18,833.

University of Canterbury Covid modeller Prof Michael Plank said overseas experience suggested demand for tests did fluctuate.

The availability of Rats now meant that demand was more spread out, as people could order the tests online or buy them at supermarkets, Prof Plank said.

There was also a well-known drop in demand for tests at weekends which could have affected numbers.

However, Prof Plank stressed it was important that positive results be reported to the Ministry of Health, as that two-minute job allowed the spread of Covid-19 to be tracked.

Despite people talking about them as being less accurate than PCR tests, Rats were really accurate if done at the right time — around the time of the onset of symptoms, and again a few days later.

Nationwide hospital admission rates continued to slowly climb over the weekend, from 562 on Friday to 618 yesterday, 10 of whom were in intensive care.

In the South, four people were in hospital with Covid-19.

Meanwhile, the virus has reached one of the most far-flung places in New Zealand — two cases were yesterday confirmed on the Chatham Islands, about 800km east of the mainland.

Canterbury District Health Board Covid-10 emergency co-ordination centre controller Helen Skinner said the cases, both Chathams residents, were in isolation there, being supported.

Dr Skinner urged islanders to get vaccinated and boosted.

"The DHB will be distributing Rats to all households on the islands early this week as a precaution to allow early detection of positive cases."