MRINZ: NZ data adds more pieces to the COVID puzzle

Dr Nethmi Kearns from MRINZ

Dr Nethmi Kearns, MRINZ Clinical Research Fellow. Photo: Rebecca McMillan.

While clinicians and researchers worldwide have been looking closely at all aspects of COVID-19, the majority of data has been limited to patients admitted to hospital and intensive care units. This has provided insights in severe COVID, but leaves out those with less-severe disease. New Aotearoa New Zealand research published on 17 September has sought to redress the balance.

The Medical Research Institute of New Zealand (MRINZ) COVID team, led by Dr Nethmi Kearns, Clinical Research Fellow, working in partnership with Regional Public Health (RPH), have analysed data on the progression, prognosis, and management of the 2020 alpha strain of all community COVID-19 cases in the Greater Wellington region.

The team’s study, ‘Clinical and epidemiological characteristics of COVID-19 in Wellington, New Zealand 2020: a retrospective, observational study’ was published in The New Zealand Medical Journal.

The Greater Wellington Region had 96 confirmed COVID-19 cases during the first wave of the pandemic from January-August 2020. Dr Kearns and her team investigated crucial data from these cases, ranging from how and when symptoms presented, the rates of secondary infection within households, the frequency of worsening asthma, and the countries from which COVID-19 was imported.

Key study findings show that the majority of these first wave cases were those travelling to Aotearoa New Zealand from overseas, and there was no set of overarching symptoms that could accurately predict infection, with a variety of different symptoms presenting from cough to stomach pain. The study also clearly shows how COVID does not provoke severe asthma attacks, a significant and crucial finding for Aotearoa New Zealand, given our high national prevalence of asthma.

Over 90% of confirmed COVID-19 cases experienced a non-life threatening form of the disease and were managed in the community. Dr Kearns, says that the majority of people with COVID do not need hospital-level care and information on this group obtained from the 2020 alpha outbreak will enable Aotearoa New Zealand to be better prepared for Delta and other subsequent strains.

Non hospitalised COVID cases pose challenges to those immediately affected, their whānau, their household, social and workplace contacts and the paramedic and primary care health professionals who provide care during the uncertain period when it is difficult to predict who could deteriorate rapidly. “It is important that the progression of COVID-19 at the less severe end of the spectrum is further explored with new variants of COVID-19,” says Dr Kearns.

Early border restrictions, mandatory quarantine of international arrivals and clear communication of risk, as seen in Wellington and in New Zealand overall during the first wave, minimised transmission from arriving travellers to at-risk communities. The study supports the assertion that by following the Alert Level guidelines and other public health advice through this first 2020 wave, New Zealand managed to keep transmission within communities to a minimum and protect our most vulnerable population members.

Dr Kearns, who returned from NHS Scotland to join the MRINZ, says, “The COVID-19 pandemic disproportionately affects our most vulnerable global communities, such as minority ethnic groups, migrant workers, women and gender-diverse communities, and those with lower socioeconomic status.”

Multiple risk factors intersect to intensify existing inequities, compounded by the structural imbalance present within many worldwide health and support systems. “Ongoing research into preventing and tackling inequity in the diagnosis and management of COVID-19 is a priority,” says Dr Kearns.

Dr Annette Nesdale, Medical Officer of Health, Regional Public Health, says, “Our collaboration with the MRINZ COVID team supports our public health and equity goals to understand and mitigate the severe impacts of the global pandemic for our local communities.”

MRINZ and RPH are currently embarking on an observational study into the impacts of Long COVID on physical and mental health across these same community cases, one year after their illness. This is a new and important extension of this research, set to continue to inform public health interventions both here in Aotearoa New Zealand, and internationally, during this and future pandemics.

Professor Richard Beasley, MRINZ Director says, “The work of Dr Kearns and our MRINZ COVID team is providing important knowledge of the wide range of symptoms in people presenting with mild COVID-19, and the difficulties in developing diagnostic clinical criteria. This research contributes to worldwide efforts to better understand and manage COVID-19, across the spectrum of its severity.”

Key points at a glance

The ‘Clinical and epidemiological characteristics of COVID-19 in Wellington, New Zealand: a retrospective, observational study’, is a community-based review, reporting on the alpha COVID-19 cases in Wellington during the first wave, January-August 2020.

The study, published in the New Zealand Medical Journal on Friday, 17 September, was authored by Dr Nethmi Kearns, Allie Eathorne, Dr Tessa Luff, Dr Ciléin Kearns, Dr Craig Thornley, Dr Alex Semprini, Professor Richard Beasley, and Dr Annette Nesdale.

The study provides community-derived data from Wellington, New Zealand, a country that at the time of writing, managed to minimise the community transmission and remain ‘ahead of the curve’, exemplifying how public health measures protected vulnerable communities.

The study illustrates how the profile of symptoms in COVID-19 was highly variable and there was no particular symptom or set of symptoms that could accurately predict infection.

The study showed that COVID does not provoke severe asthma attacks, an important finding given New Zealand has such a high prevalence of asthma.

An observational study into the long-term impacts of Long COVID on physical and mental health for these same community cases, one year after their illness, is a new and important extension of this research.

Background study details

The aim of the ‘Clinical and epidemiological characteristics of COVID-19 in Wellington, New Zealand: a retrospective, observational study’ was to review the demographic and clinical characteristics of confirmed COVID-19 cases within the Greater Wellington Region (GWR).

This was a retrospective, observational study of all 96 confirmed COVID-19 cases in the GWR between January 1-August 1, 2020. The primary outcome was time taken from onset to complete resolution of symptoms. Secondary outcomes were the epidemiological and clinical characteristics of cases.

The mean (SD) time from symptom onset to complete resolution was 19.1 (1.1) days. The mean (SD) age was 43.1 (16.9). 51% were male. The majority were of European ethnicity (84%), resided in the top five decile neighbourhoods (76%) and had travelled to New Zealand (69%). The mean (SD) time from onset of symptoms to obtaining RT-PCR testing results was 5.3 (0.4) days. The most common symptoms at onset were cough (36%), sore throat (22%) and fatigue (21%); the overall most common symptoms were cough (65%), sore throat (43%), headache (43%) and fatigue (42%); many symptoms were late manifestations. The most common co-morbidity reported was asthma (20%), with no reported exacerbations. The rate of secondary infections within households was 0.05 per primary infection.

The demography of COVID-19 cases reflected the imported nature of cases. The clinical presentation of COVID-19 was highly variable and there were no particular symptoms that could accurately predict infection.


Medical Research Institute of New Zealand

The Medical Research Institute of New Zealand (MRINZ) is Aotearoa New Zealand’s leading independent medical research institute, committed to research that changes clinical practice for the better. The MRINZ is an internationally recognised academic institution and operates under a charitable trust pursuing advances in clinical practice. MRINZ’s research teams are dedicated to investigating the causes of important public health problems, to delivering high quality evidence on which to improve the management of diseases and patient care across a wide range of fields, and providing a base for specialist training in medical research.

Dr Nethmi Kerns

Nethmi is a Clinical Research Fellow at the Medical Research Institute of New Zealand (MRINZ) and a Registrar in Public Health Medicine. She grew up in Auckland but completed her undergraduate medical training at the University of Edinburgh in Scotland before returning to Aotearoa New Zealand. She is currently completing her M.D at MRINZ investigating the use of inhaled steroids in acute asthma. She is also undertaking a Master of Public Health at the University of Otago Wellington where her dissertation focuses on the effects of COVID-19 response measures on the epidemiology of infectious diseases in Aotearoa New Zealand. Currently, Nethmi is supporting the COVID-19 response at Regional Public Health alongside her research and university papers.

Date posted: 20 September 2021

Facebook Feed