New Zealand competition to eliminate the coronavirus again

A week ago, New Zealand was an example of how quick and decisive behavior could control the spread of coronaviruses. No locally acquired cases of COVID-19 have been reported since the beginning of May. However, the emergence of this week’s collection of incidents (now 30) surprised the country and hit the government’s strategy to eliminate the virus.

Amanda Kvarsbig, an epidemiologist at the University of Otago in Wellington, is helping the country respond to COVID-19. She spoke Nature Respond quickly to new cases and see if eradication strategies are still possible.

How has the mood in New Zealand changed?

The new case was a shock. When they were announced, New Zealand had over 100 days of uncommitted community infection despite extensive testing. The country is at the lowest level of alert and is capable of nearly normal activity despite the strict controls that require foreign travelers to remain in quarantine for two weeks. There was a general sentiment that we had beaten the virus — government officials and public health experts were warning about self-satisfaction.

Now that anxiety is widespread, there are long lines of people at the COVID-19 test station, and some even panic buying in supermarkets.

What is the public health reaction to these new infectious diseases?

The response, backed by decisive government action, was swift. The Auckland region where the case was identified is currently at alert level 3 (the second highest of the four levels) and people are instructed to stay home except for essential movements. The rest of the country is at alert level 2. This includes physical distance measurements and gathering limits.

COVID-19 people and their contacts have been tested and tracked. These are familiar measures, but there are some new approaches. For example, the government currently recommends the use of face masks, and people with COVID-19 in the community spend isolation periods in private facilities rather than at home.

Me and other public health advocates strongly recommend the use of masks throughout the population. This could help the country avoid future blockades. Clear risk advice is also helpful. For example, there is evidence that the virus can spread quickly in a closed environment where people are talking, laughing, and singing. This changes the way we think about “mass gathering” and gives a more subtle sense of where the risk lies.

What do you know about the original source?

A new case became apparent when a person in his 50s developed symptoms and was presented for examination. Following that first positive test, their household and other contacts were tested to identify additional cases.

The new cases all appear to be part of the same cluster, but they are not linked at the time of their introduction into the country. I’m worried because I don’t yet know how long this problem has spread and how many other cases may have been missed. Ideally, a survey would allow the public health system to “backtrack” to identify each source of known cases, and then “forward trace” to identify other close contacts of that source. Become.

Authorities are exploring the possibility that the virus arrived in refrigerated packaging. It’s certainly worth investigating, but the global experience of COVID-19 outbreaks has so far led to close contact between individuals on their way to New Zealand or during quarantine at the border. It has been suggested that it is much more likely to have done so.

Did the virus go undetected in the community for some time?

The current case may be several generations above the original introduced case. Approximately one-third of COVID-19 cases do not cause symptoms, so the transmission chain can propagate for several generations before someone feels ill enough to be tested.

Another factor is that winter coughs and colds make it difficult to detect a surge in COVID-19 infections in the community. New Zealand uses surveillance systems to track flu-like illnesses. There has been no major rise in these diseases over the last few weeks. In fact, the incidence is still much lower than normally seen at this time. While it is certain that more cases will be detected in the future, this is encouraging, as it suggests that a large number of undetected COVID-19s is unlikely.

What somehow crossed the border seems to be a more recent infection. But it’s good to know exactly when and how it arrived.

What can genomics tell us about this latest outbreak?

Genomic epidemiology is a particularly powerful tool for tracing outbreaks to their source, so it is particularly relevant to the current situation where the original case is still unknown. Genome sequencing Survey New Zealand’s COVID-19 Cluster Earlier this year, and in some cases, investigators were able to link cases to known clusters when traditional public health methods could not. You can also identify situations where the cases appear to be closely related, but actually belong to different clusters.

If all the Auckland cases turn out to be from one cluster, that’s good news for outbreak control. If you have multiple clusters, more widespread transmission is suggested.

New Zealand has adopted an elimination strategy. Does this latest fashion suggest that it is impossible?

New Zealand has previously eliminated community infections and knows that they can. I hope to get out of elimination in the near future. The goal is to keep the spread of the community at zero, but the country is always at risk of cross-border transmission. There is no border control system that is 100% failsafe. But since we’re starting with a baseline of exclusion, each new epidemic will be done using all the controls we have at our disposal, including case and contact management, physical distance and mass masking. It is feasible to extinguish.

We were fortunate to have demonstrated outstanding political and scientific leadership in New Zealand. This has created swift and decisive action to protect the health of the population. A key element of New Zealand’s response was good communication with the public about what is happening and what is expected.

High levels of compliance are proof of the trust people now hold in government, as strict control measures have made many people difficult. We have also seen a great deal of compassion and innovative spirit throughout the country. Control measures place a heavy burden on low-income communities, especially the Maori and Pacific populations. However, community organizations, especially Maori-led organizations, have provided significant support, provided food parcels, and realigned health and social services to make them accessible to those who need them most.

This interview has been edited for length and clarity.