Health experts are criticising the Government's new COVID-19 testing strategy, believing the sustained high focus on community tests is diverting staff and resources away from usual care.
Minister of Health Dr David Clark announced on Tuesday anyone who goes to primary or secondary care with COVID-19 symptoms will be offered a test, even if they have no history of international travel or contact with travellers. It was also revealed border staff, air and maritime crew, and workers in manage isolation and quarantine facilities will now be prioritised for virus tests.
Associate professor Lynn McBain from the University of Otago in Wellington says the enhanced regulations that will see border workers and those working in quarantine facilities tested more frequently is a good step forward since the border "is clearly the weakest point".
But she's concerned a test will be offered to anyone who has symptoms consistent with COVID-19, because there's currently an increasing number of low-level respiratory infections circulating that will spread throughout communities.
"This means that there will be increasing numbers presenting for testing as the current case definition for COVID-19 is very broad," she says.
The Ministry of Health's current case definition is: "Any acute respiratory infection with at least one of the following symptoms: cough, sore throat, shortness of breath, coryza, anosmia with or without fever."
Prof McBain says she agrees with community testing, but believes there's a risk that the number of tests required to test everyone with all symptoms will mean health services "are diverting staff and resources to testing and away from usual care".
"A way forward might possibly be looking at alternative modelling for community testing - perhaps sentinel testing, or other ways to have continued confidence in the lack of community spread - but not needing to test everyone with a runny nose or sore throat. There is not a simple solution."
Canterbury District Health Board clinical director of microbiology Dr Joshua Freeman says the case definition is due for an update.
"The latest COVID-19 testing strategy announced today by David Clark is a mixed bag. It certainly makes sense to increase systematic testing of those working at our borders and those exempted from quarantine.
"However, the suspect case definition used to determine who should get tested more generally, is overdue for change and is no longer fit for purpose. Testing everyone presenting to hospital with a runny nose or sore throat is, in our experience, having negative downstream consequences on the delivery of healthcare."
He says when the current suspect case definition was introduced several months ago, there was more uncertainty about community transmission and "it made sense" to test everyone who had symptoms. However, now the probability of undetected chains of community transmission is "vanishingly low", broad and undirected testing doesn't have its benefits and there's risk of harmful flow-on effects.
These effects occur because a large number of patients incidentally meet the COVID-19 case definition since the symptoms are non-specific and they could be due to unrelated health conditions.
"In accordance with Ministry of Health advice, these patients tend to be managed in single rooms with full PPE [personal protective equipment] until test results become available. This leads to unnecessary consumption of PPE and laboratory resources, but more importantly, slows patient transfer to specialty wards where they can be managed most appropriately," Dr Freeman says.
But Massey University senior lecturer Dr Nikki Freed in the School of Natural and Computational Sciences believes having a broad definition for testing underscores how vigilant New Zealanders will need to be in keeping COVID-19 case numbers low.
"There are several important steps in these new changes which will help the Ministry of Health catch cases at the border, and importantly, find any COVID-19 cases that might be circulating in the community.
"The first is setting a low bar for testing, so that anyone presenting with symptoms is able to get tested, and second is identifying groups who are under-tested. Knowing where the 'holes' are in community testing is an important step to making sure the surveillance is working."
Nearly 350,000 people have been tested for the virus in New Zealand to date, which Clark says is the "highest rate of tests per confirmed COVID-19 case in the world".