No new cases of COVID-19, 22 September
There are no new cases of COVID-19 to report in New Zealand today.
There are 39 people isolating in the Auckland quarantine facility from the community, which includes 18 people who have tested positive for COVID-19 and their household contacts.
Three people are in hospital with COVID-19 – one each at Auckland City, Middlemore and North Shore hospitals. All three patients are in isolation on a general ward.
Since August 11, our contact tracing team has identified 4,003 close contacts of cases, of which 3,992 have been contacted and are self-isolating or have completed self-isolation. We are in the process of contacting the rest.
There is one additional previously reported case that is now considered to have recovered from COVID-19.
Our total number of active cases is 61; of those, 29 are imported cases in MIQ facilities, and 32 are community cases.
Our total number of confirmed cases of COVID-19 remains at 1,464.
Yesterday our laboratories processed 3,278 tests, bringing the total number of tests completed to date to 917,699.
It is worth reiterating here that even with the shifts in Alert Levels we should remain vigilant as the risk, although small, remains.
In particular, people should monitor their health and if symptoms appear, stay home and seek a test.
Historical cases
We are seeing test results that are coming through from time to time that indicate a historical infection. In these instances, the test result comes back positive but with a high “cycle threshold”, or CT value, which we call a weak positive result. Importantly, there is research internationally that shows such people are not infectious.
Sometimes these people seek testing because they have a respiratory illness, and it seems that an acute non-COVID respiratory illness then creates the condition where a residual COVID-19 virus is detected.
Over the past two months we have seen four different examples of this.
First, there have been people who have travelled from New Zealand and have returned a positive PCR result on arrival in another country. On further follow-up, it is apparent that these people are not acutely infected, and they were not recently infectious before leaving New Zealand.
The second group are people who arrive into New Zealand and who return a positive test in managed isolation – or subsequent to leaving managed isolation after testing negative during their period there – without acute symptoms.
A third group are people who have been in New Zealand throughout the pandemic who return a positive PCR result and who had a documented infection earlier in the year, and are already in our case count.
Finally, there is a fourth group of people who have been in New Zealand throughout the pandemic who return a positive PCR result and who do not have a documented infection earlier in the year, so they are not in our case count. These people have a clear history of a previous acute illness consistent with COVID-19 but were not tested at the time, and follow-up serology testing confirms that they (and possibly other members of their family) have been infected in the past with COVID-19.
In all these cases, the test result is often a ‘weak positive’ and the CT value of the person’s PCR test suggests an old infection.
The Ministry of Health is developing a protocol and setting up an expert panel to help standardise the way these cases are managed and reported.
In particular, the panel and protocol will help ensure a consistent approach to cases that are effectively borderline cases that are being further investigated.
The panel and protocol will assess individuals returning a weak positive PCR test with a high CT value to determine whether the infection is historical or recent and guide public health measures, especially regarding contact management and any steps required to limit risk to the community.
These historic cases under investigation will be included in our future reporting. Where it is concluded they have definitely been infected with COVID-19, but are not already included in either New Zealand’s or another country’s case numbers, they will be added to our total number of either confirmed or probable cases.
To reiterate, these people are not infectious and don’t pose a risk to others.
Contacts from Auckland flight
An update now on the case of the man who left MIQ in Christchurch having returned negative tests for COVID-19 and then tested positive in Auckland.
We have recorded 85 close contacts from the charter flight from Christchurch to Auckland.
Of those, 29 have been tested. These include the people closest to the person on the flight. 28 have returned a negative result. The remaining person returned a positive test with a high CT value yesterday, which suggests an old infection.
The person, who has had no symptoms since arriving in New Zealand, was retested and returned a negative result this morning and serology testing is also being undertaken
This person had also already returned negative day 3 and day 12 tests while in managed isolation.
This person remains under investigation to confirm that this is an historic case, and whether it has already reported as a case in India.
Meanwhile, a precautionary approach is being taken and the person has been transferred to the Auckland quarantine facility.
The remaining people on the flight are in the process of being contacted and will be tested as appropriate.
