Public Health Expert

Pandemic terminology: getting it right matters for effective risk communication and management - Public Health Expert

Jun 30, 2020

Prof Nick Wilson, Dr Amanda Kvalsvig, Prof Michael Baker Compared with other OECD countries NZ is a stand-out success story by ending community transmission of COVID-19. While there have been some well-publicised recent deficiencies (eg, quarantine organisation), there has still been no evidence of community transmission for many weeks. Nevertheless, further improvements in NZ’s response are possible and in this blog we detail how pandemic terminology could be upgraded. Consistent, accurate terminology could assist effective communication between political leaders, officials, scientists, international collaborators and the NZ public on key COVID-19 risk management issues. Clear communication with the public is critical for managing the COVID-19 pandemic. Indeed, it appears to have been a major strength to date by NZ political leaders and officials (eg, Prime Minister Jacinda Ardern and Director General Ashley Bloomfield). Nevertheless, there is further scope for improvement. In … Read More

Preventing Outbreaks of COVID-19 in NZ Associated with Air Travel from Australia: New Modelling Study of Alternatives to Quarantine - Public Health Expert

Jun 17, 2020

Prof Nick Wilson, Prof Michael Baker, Prof Martin Eichner (*author details) In this new study, we estimated the risk of COVID-19 outbreaks associated with air travel from Australia (with a low prevalence of COVID-19 infection) to NZ. We found that the combined use of exit and entry screening, two PCR tests (on days 3 and 12 in NZ), mask use and contact tracing, reduced the risk from one outbreak every 1.7 years (no interventions) to every 29.8 years (95% uncertainty interval: 0.8 to 110). This risk is similar to that achieved by the current system of 14 days quarantine, at one outbreak every 34.1 years (0.06 to 125). In conclusion, multi-layered interventions can markedly reduce the risk of importing the pandemic virus into a COVID-19-free nation like NZ. Whatever approach is chosen, careful management and evaluation will be needed. Read More

After the new law for smokefree cars for Kiwi kids, what next? - Public Health Expert

Jun 04, 2020

George Thomson, Nick Wilson, Richard Edwards This blog discusses the passing of the Smoke-free Environments (Prohibiting Smoking in Motor Vehicles Carrying Children) Amendment Act last week. We briefly review some lessons from this legislation’s long journey and explore future smokefree possibilities in Aotearoa / New Zealand.   A law providing smokefree cars for children is a matter for delight. Many have worked hard and long for this, community workers, advocates, researchers, officials and policymakers. As we celebrate the passing of legislation which will require cars carrying those under 18 years to be smokefree, what can we learn from the process for smokefree and wider health matters? Why was the policy process for the law so long? It is over 45 years since the first smokefree places law in the world,1 over 35 years after there was clear evidence … Read More

When can COVID-19 be Declared Eliminated from NZ? New Modelling Study - Public Health Expert

May 25, 2020

Prof Nick Wilson, Dr Matthew Parry, Dr Ayesha Verrall, Prof Michael Baker, Prof Martin Eichner (author details*) This blog details a recent modelling study we conducted. In it, we estimated that it would take between 27 and 33 days of no new detected cases of COVID-19 for there to be a 95% probability of epidemic extinction in NZ (at around current testing levels). For a 99% probability of epidemic extinction, the equivalent time-period was 37 to 44 days. So now the country urgently needs the Ministry of Health to provide an official definition of elimination and to upgrade the data on its website so that the public, the media and researchers can monitor progress towards achieving the goal. NZ is a rare example of a country to clearly articulate an elimination goal for the SARS-CoV-2 pandemic virus that causes … Read More

Monitoring and Forecasting the COVID-19 Pandemic in New Zealand Including the Successful Impact of the Lockdown - Public Health Expert

May 22, 2020

Dr Jaijus Pallippadan-Johny1, Dr John McDermott2, Rodney Jones1 and Michael Duddin1 (1 Wigram Capital Advisors, Auckland; 2Motu Economic and Policy Research, Wellington) In this blog, we introduce our modelling approach to estimating the transmissibility of the SARS-CoV-2 virus, the cause of the COVID-19 pandemic. We demonstrate the usefulness of the Wallinga model for the calculation of the effective reproduction number and show the major impact of the lockdown on containing the pandemic in New Zealand. The global COVID-19 pandemic represents an unprecedented public health and economic crisis. As the SARS-CoV-2 virus spread across the globe in early 2020, there was a clear need to find a modelling approach that could be used by policymakers and non-specialists to monitor the spread of the virus, and allow timely risk assessments to be made at critical times. The reproduction number (R0) is an … Read More

Why a “mouth and nose” lockdown with masks might help avoid a “full body” lockdown at home - Public Health Expert

May 20, 2020

Prof Nick Wilson, Dr Sophie Febery, Dr Ling Chan, Dr Jennifer Summers, Prof Michael Baker The concepts of an Alert Level system, household “bubbles”, and social event size limits are all valuable pandemic control measures. Nevertheless, better “source control” of COVID-19 at various Alert Levels by requiring masks in public indoor spaces could reduce the risk of outbreaks (should there be border control failures) and reduce the likelihood that we would need to move back to tighter restrictions and lockdowns with the associated adverse economic, social and mental health effects.   Typical street/shopping scene in Hong Kong with everyone wearing a mask (photo from author [LC] personal collection) The spread of the SARS-CoV-2 virus appears to be mainly through conversational contact, at home and at social events. Both internationally and in New Zealand, large clusters are usually initiated by … Read More

The Strong Case for Mask Requirements in Public Transportation and Border Control Settings in NZ’s Current COVID-19 Pandemic Context - Public Health Expert

May 11, 2020

Prof Nick Wilson, Dr Sophie Febery, Dr Ling Chan, Dr Amanda Kvalsvig, Prof Michael Baker In this blog we identify six likely benefits from requiring fabric mask use in public transportation and border control settings in the “peri-elimination” context that New Zealand is currently in. Given these likely benefits and the relatively low costs (especially if the Government provides free masks as per Hong Kong), such a policy should be given very serious consideration by health authorities in the transition to level 2. As detailed in a previous blog post, the case for mass masking (i.e., wearing masks for source control as a population health intervention) for SARS-CoV-2 control is becoming increasingly compelling and many countries are adding masking policies to their pandemic response. High quality randomised controlled trial (RCT) evidence on mass masking is not available. However, there … Read More

The need for a robust scientific definition for the elimination of COVID-19 from New Zealand - Public Health Expert

May 05, 2020

Prof Michael Baker, Prof Nick Wilson, Prof Shaun Hendy, Prof David Skegg New Zealand is making good progress towards its elimination goal for COVID-19 at the country-level. In this blog we present the case for a scientific definition of elimination to help guide our national COVID-19 response. The definition must be objectively verifiable, with appropriate levels of testing and surveillance systems in place. It should ideally be refined in collaboration with Australian health authorities, as part of a strategy of opening up our shared borders for easier travel between the two countries. In common language, the words “elimination” and “eradication” are often used interchangeably, but a distinction is made in the field of infectious disease epidemiology. Eradication is the “permanent reduction to zero of the worldwide incidence of infection caused by a specific agent…” [1]. The global eradication … Read More

What we would like to see on the Ministry of Health’s website to better inform progress on COVID-19 elimination - Public Health Expert

May 03, 2020

Gordon Purdie, Nick Wilson, Michael G Baker In this blog we analyse data from the Ministry of Health’s COVID-19 website and display a key graph that we think should be routinely on that website. We also detail a potentially more useful way to categorise case data so that the public and research community can better track progress on the path to COVID-19 elimination. Both the graphical and tabular presentation of case data need to emphasise the critical distinction between imported cases (who should be safely isolated in supervised quarantine facilities) and transmission within NZ that would threaten elimination status. People infected with the coronavirus SARS-CoV-2 that causes COVID-19, and detected in NZ, belong to one of two broad groups: infected overseas or infected within NZ. The Ministry of Health (MoH) provides some data on confirmed and probable cases. Read More

Why NZ should consider adopting “mass masking” as an additional step to speed elimination of the Covid-19 pandemic - Public Health Expert

Apr 22, 2020

Dr Ling Chan, Dr Sophie Febery Widespread public mask use is common in some Asian countries as a control measure in the current Covid-19 pandemic. There is some suggestive laboratory and epidemiological evidence of benefit for such mask use. Since the costs of mass masking are relatively low and there are no apparent substantial down-sides, it should be given serious consideration by the NZ Government to speed progress towards the elimination goal. There is no doubt that surgical masks can be used to reduce the spread of respiratory infections [1]. In health care settings masks are used widely for infection control – though it is still not proven that N95 respirator masks are superior to surgical masks eg, for preventing influenza infection [2]. In this blog we focus more on the potential role of masks in contributing to reducing the spread … Read More