Prof Nick Wilson, Dr Julie Bennett, Dr Leah Grout, Dr Jin Russell, Dr Jennifer Summers, Prof Michael Baker
Despite some good progress, the persisting Covid-19 outbreak in Auckland still poses risks to health, social wellbeing and the economy. There is a need for accelerated efforts to ensure more rapid elimination of community transmission. In this blog we look at five critical measures to implement immediately, along with a range of other Covid-19 control measures that will help Auckland and the whole country sustain elimination in the medium term.
Image by Luke Pilkinton-Ching, University of Otago Wellington
It is critical that Aotearoa NZ continues with its elimination strategy and successfully ends the current outbreak in Auckland. The impact of failure can be seen in New South Wales and Victoria in Australia where there are mounting cases, hospitalisations and deaths from Covid-19. Furthermore, these Australian states will probably need to maintain intense restrictions for some months so that these outbreaks don’t completely overwhelm healthcare systems. Also, there is growing concern that conditions such as “long Covid” have potentially very long-term impacts. One commentator suggests a best assumption of 2-3% of those who get Covid-19 will have a crippling “long Covid” similar to chronic fatigue syndrome [1].
Five critical measures to regain Covid-19 elimination status in NZ
1. Enhance surveillance for Covid-19 infections. There are recent efforts to enhance focused community testing in suburbs of Auckland where undetected community transmission may be occurring. These efforts are very welcome but need to be further expanded to include the widespread testing of essential workers in large workplaces, testing of people visiting supermarkets, and testing of all attendees and visitors to hospitals on entry or weekly for regular visitors. There is also a need to expand wastewater testing to more suburbs in Auckland – so that case finding can be more focused (as per the successful approach to identify cases in Warkworth a few weeks ago [2] and to respond to a recent positive result for wastewater from Pukekohe [3]).
2. Accelerate vaccination of the Auckland population, particularly essential workers, Māori and Pasifika. The recent progress with vaccination delivery in Auckland has been impressive – particularly with drive-in clinics; walk-in clinics; pop-up clinics in places such as churches and marae; and the just-announced mobile clinics. But we would like to see an even stronger focus on reaching out to essential workers eg, with 24-hour drop-in clinics (as used in the UK), and taking mobile vaccination services to large workplaces, and requiring vaccination for any essential workers travelling outside of Auckland. More generally, there is probably a need for more funding and workforce support for Māori and Pasifika initiatives to provide ready access for vaccinating these priority populations (as recently argued for by a Māori health leader [4]).
3. Consider further reducing essential worker activity in Auckland (both total numbers and per workplace). There are many workplaces operating in Auckland at Alert Level 4 that are not critical in terms of food provision, healthcare provision, or keeping essential services running (transportation, electricity, sewerage, etc). That is, there are factories producing goods for other sectors of the economy (building supplies, etc) and for export. Where these workplaces are in suburbs in Auckland where there might be persisting community transmission – they could be closed until Alert Level 4 ends. Appropriate economic compensation from the Government would be required for the workers and employers involved. The recently revised Auckland District Health Board policy reducing visitor numbers to their hospitals, in-line with the highly restricted policies used by other DHBs, illustrates the opportunities available to minimise movement and mixing of people at Alert Level 4.
4. Expand Alert Level 4 mask requirements. To maximise effectiveness and simplicity of implementation – masks should be mandatory at all indoor settings outside the home at Alert Levels 3 and 4. This requirement would ensure that all essential office and factory workers are better protected.
5. Enhance economic support for citizens in Alert Levels 3 and 4. Economic support is vital to mitigating household hardship associated with lockdowns. Supplying households with adequate income enables compliance with restrictions to increase. An urgent boost to income support for people receiving benefits is highly recommended, to take effect as soon as possible. This could look like immediately bringing forward the increases to core benefits that are promised in April 2022. Hardship assistance should be easy to access on a high trust model similar to the wage-subsidy model, not requiring overly burdensome proof, and should be in the form of monetary grants which increase the agency of families to meet their own financial needs, rather than in the form of loans or food parcels. Increases to the Working for Families Tax Credit would help all low-income families with children, whether or not they had paid work.
Five additional measures for preventing future outbreaks in Auckland and NZ
1. Substantially decrease numbers of Covid-19 positive travellers arriving in NZ. Options include the introduction of additional pre-departure rapid antigen testing at the overseas airport, requirements to be fully-vaccinated before travel, and putting caps on numbers from the highest risk countries. Rapid antigen testing could also be considered on arrival so that infected travellers could be transported directly to specialised MIQ facilities with enhanced containment capacity (see below).
2. Commit to having MIQ facilities (for infected people and travellers from high-risk countries) that are outside of cities as soon as possible to minimise the risk of future Covid-19 outbreaks. This improvement is because MIQ facilities in re-purposed hotels are generally not fit-for-purpose (as per a study covering ones in both Australia and NZ [6]). Facilities need to be built outside of cities (eg, on a military base such as Ōhakea [7] that can house live-in staff and is close to Palmerston North Hospital). Nevertheless, re-purposed hotels in cities could perhaps still be used for travellers from low risk countries who test negative at the airport on arrival.
3. Expand testing options, including more saliva PCR testing and rapid antigen testing for specific situations (we will shortly publish a blog on the latter). In the present outbreak, rapid antigen testing would be particularly useful for essential workers travelling out of Auckland (but in the future, such testing could be used to regularly test all essential workers). As the latter test can take up to 30 minutes to get a result – people could be tested but then be able to travel – but with the requirement to immediately return if sent a message about having had a positive test result.
4. Upgrade the Alert Level system as we have previously outlined in a journal article [5] and in a recent blog. Such a revision would also ensure that there is a new Alert Level 1 that it is fit-for-purpose in the Delta variant environment. A key element of the upgrade is to build in universal masking in indoor environments where and when needed. Active work is needed to better support universal masking including mask quality, supply, equity, and user knowledge and practise. Considerable thought will need to be given to ensure gatherings shift outside and to set tight maximum numbers for indoor events along with universal mask requirements. At some high Alert Levels, consideration could be given to mandating that essential workers use digital tools to facilitate contact tracing (albeit tools that are improvements on the current ones).
5. Improve ventilation for all indoor settings. Despite the importance of improved ventilation in many settings (see our recent blog on the topic and for ventilation in schools), the NZ Government is relatively quiet on this topic. It should consider a campaign to promote improved ventilation in all settings (often as simple as opening windows), along with economic support to enhance ventilation and HEPA filtration in offices and factories with essential workers operating in Alert Level 4. After an Auckland-focused campaign, there could be a national campaign to improve ventilation.
* Author details: Dr Jin Russell is a PhD student at the School of Population Health, University of Auckland and consultant developmental paediatrician in Auckland. All other authors are at the Department of Public Health, University of Otago, Wellington.
References
- Pueyo T. The Most Alarming Problem about Long COVID: It’s Probably Chronic Fatigue Syndrome. September 2021; https://unchartedterritories.tomaspueyo.com/p/long-covid-chronic-fatigue-syndrome.
- Williams C. Covid-19: Warkworth residents asked to get tested after virus found in wastewater. Stuff 2021;(21 August). https://www.stuff.co.nz/national/health/coronavirus/300388198/covid19-warkworth-residents-asked-to-get-tested-after-virus-found-in-wastewate.
- Ministry of Health. 15 community cases of COVID-19; two border cases in managed isolation. (Media Release) 2021;14 September. https://www.health.govt.nz/news-media/media-releases/15-community-cases-covid-19-two-border-cases-managed-isolation.
- Quinn R. Auckland vaccine programme director hopes for record-breaking week. Radio New Zealand 2021;(14 September). https://www.rnz.co.nz/news/national/451418/auckland-vaccine-programme-director-hopes-for-record-breaking-week.
- Kvalsvig A, Wilson N, Davies C, Timu-Parata C, Signal V, Baker MG. Expansion of a national Covid-19 alert level system to improve population health and uphold the values of Indigenous peoples. Lancet Reg Health West Pac. 2021;12:100206.
- Grout L, Katar A, Ait Ouakrim D, Summers JA, Kvalsvig A, Baker MG, et al. Failures of quarantine systems for preventing COVID-19 outbreaks in Australia and New Zealand. Med J Aust. 2021.
- Wilson N, Baker M. Shifting all Isolation/Quarantine Facilities to a Single Air Force Base: The Need for a Critical Analysis. Public Health Expert 2020;(14 September). https://blogs.otago.ac.nz/pubhealthexpert/2020/09/14/shifting-all-isolation-quarantine-facilities-to-a-single-air-force-base-the-need-for-a-critical-analysis/.
I hold that we are failing to mitigate this virus with maximum benefit-cost because there is still so much confusion over how it spreads, which is a legacy of the WHO holding to a wrong position for far too long. They were wrong repeatedly, and mostly they quickly changed their position – remember “no evidence of human to human transmission”? But no error they have perpetuated has been as costly as their April 2020 position that “Covid is NOT airborne”.
Your posting is absolutely correct that the government of NZ is failing dismally to convey the right messages, which is inexcusable in September 2021. Here is one of the top aerosols experts, Prof Jose-Luis Jimenez explaining in a long TV interview in October 2020, how “aerosol spread” should be the orthodoxy even back then.
https://www.youtube.com/watch?v=tJSPL9LQCiM
NZ is accidentally gaining benefit from the natural ventilation rates of its predominant housing and building types, which is a legacy of our mild range of temperatures, strong breezes most of the time, and popular building materials and methods. There is a lot of fool’s luck in our globally outstanding achievements to date.
Some Australian experts have already made the perfect “public messaging video” on the subject of ventilation. How many New Zealanders have seen any public advice of this quality yet?
https://www.youtube.com/watch?v=hGYyi5DqOzE
Regarding your point about MIQ facilities needing to be outside cities, I had a letter published in the NZ Herald arguing this months ago. I was arguing for aerosol risk mitigation well before the last quarter of last year. By then I was well aware of the raging debacle between the WHO and hundreds of experts; this was especially infuriating to me because without any specialist knowledge, it was intuitively obvious long since that “contact, droplets and fomites” could not possibly explain the patterns of global spread, the level of severity of impact, and the greatly overdispersed nature of spread locally. By September 2020 even the New York Times was publishing informative arguments with titles like “Just Stop The Superspreading”.
I was using Medium.com to post regular essays on the state of knowledge concerning aerosols and Covid spread. I raise the question now, why is Covid so extremely politicized that even my aerosol-science-based arguments ultimately got me permanently banned from Medium.com? It is as if there are dark forces with an underlying agenda that NEEDS the “contact, droplets, fomites” orthodoxy to justify mitigation strategies that actually do not work and which result in the perpetuation of both the pandemic and those strategies! I hope that New Zealand can do better.
One writer, Zeynep Tufekci of “Atlantic” Magazine has been consistently the best investigative journalist on this subject and has ended up co-authoring papers with academics. Her long essay of October 2020, “This Overlooked Variable Is the Key to the Pandemic: It’s not R” contains excellent advice about cost-effective track and tracing when spread is actually overdispersed. It is a travesty that in September 2021, any nation is still fooling around with tracing methods that do not focus on the low-hanging fruit of superspreading “events”. As Tufekci writes:
“…Overdispersion should also inform our contact-tracing efforts. In fact, we may need to turn them upside down. Right now, many states and nations engage in what is called forward or prospective contact tracing. Once an infected person is identified, we try to find out with whom they interacted afterward so that we can warn, test, isolate, and quarantine these potential exposures. But that’s not the only way to trace contacts. And, because of overdispersion, it’s not necessarily where the most bang for the buck lies. Instead, in many cases, we should try to work backwards to see who first infected the subject.
Because of overdispersion, most people will have been infected by someone who also infected other people, because only a small percentage of people infect many at a time, whereas most infect zero or maybe one person. As Adam Kucharski, an epidemiologist and the author of the book The Rules of Contagion, explained to me, If we can use retrospective contact tracing to find the person who infected our patient, and then trace the forward contacts of the infecting person, we are generally going to find a lot more cases compared with forward-tracing contacts of the infected patient, which will merely identify potential exposures, many of which will not happen anyway, because most transmission chains die out on their own…
“…as Kucharski and his co-authors show mathematically, overdispersion means that “forward tracing alone can, on average, identify at most the mean number of secondary infections (i.e. R)”; in contrast, “backward tracing increases this maximum number of traceable individuals by a factor of 2–3, as index cases are more likely to come from clusters than a case is to generate a cluster.”
The expert orthodoxies being so slow to recognize aerosol spread as the main factor, has led to an error cascade in understanding of the entire pandemic. A highly important paper that raises the right questions, has been overlooked: Nov 25, 2020: Van Damme, Dahake, Van de Pas, Vanham and Assefa: “COVID-19: Does the infectious inoculum dose-response relationship contribute to understanding heterogeneity in disease severity and transmission dynamics?”
My answer to the question posed in the title of this paper is: this is blindingly obvious. The greatest death rates are to be found where people are exposed to built-up aerosols in the indoors environment, around the clock, 24/7. Rest homes are obviously the worst case. They often tend to lack ventilation, i.e. air exchange via the HVAC system, because managing the risk of chills is important for the elderly, but the cost of heating or cooling air drawn in from outside is high. So air is recirculated endlessly, when the season is cold or hot.
The impact of Covid on prisons in some parts of the world is a similar case, although obviously not as severe because they are not kept so stuffy, and the inmates are not as old and frail.
Other obvious pointers to indoor-environment risk, includes the frequency of superspreading from meat packing plants and cool stores. Of course these environments are “not ventilated”. At least the workers do spend most of each 24 hour period, away from that environment.
Van Damme et al commence their paper with this paragraph:
“The variation in the speed and intensity of SARS-CoV-2 transmission and severity of the resulting COVID-19 disease are still imperfectly understood. We postulate a dose-response relationship in COVID-19, and that “the dose of virus in the initial inoculum” is an important missing link in understanding several incompletely explained observations in COVID-19 as a factor in transmission dynamics and severity of disease. We hypothesize that: (1) Viral dose in inoculum is related to severity of disease, (2) Severity of disease is related to transmission potential, and (3) In certain contexts, chains of severe cases can build up to severe local outbreaks, and large-scale intensive epidemics. Considerable evidence from other infectious diseases substantiates this hypothesis and recent evidence from COVID-19 points in the same direction…”
I strongly recommend the discussions in that paper under the following headings:
The inoculum theory provides a logical explanation for several “incompletely explained observations” in COVID-19 epidemics
and
Proposed research avenues
It would be too lengthy to just paste the discussion here. The authors point out the importance of the correlations that others have been pointing out for up to a year already, and the failure of public health officials thus far, to ask the right questions of patients to determine the correlations between circumstances and severity of infection. The most important one being duration in the aerosol-laden environment. As Van Damme et al point out, it is difficult to create an “inoculum dose / illness severity” hypothesis around contact, droplets and fomites but it makes it all the more obvious that aerosols are the main means of spread.
The seemingly random severity of Covid illness between different individuals is actually not as random as we think, and the role of the individuals immune system is not the decider it has been assumed to be. It is a factor in an equation, in which inoculum dose is actually the most important factor. Anecdotal evidence and reportage abounds of rare cases of “young, healthy” people dying of Covid; and I assert that if the right investigations were done, these people would be found to have received a high inoculum dose of aerosolized virus, possibly unluckily at more than one location including their own apartment in a building with internally recirculated air; local cafes, bars and nightclubs; and gymns.
If we understood this properly, we would understand how to prevent DEADLY and severe Covid infection, while not worrying and wasting efforts against the great majority of spread that by its nature creates asymptomatic and mild infections only. If the whole country could get infected at the supermarket, that would be a plus, not a minus. These environments have massive air volumes per person, tend to be ventilated adequately to the outside (one even regularly sees birds flying around inside them) and there is well over a year of experience and data now to show that even the checkout operators do not suffer occupational risk to anything like the same extent as, say, meat packing plant workers.
Seeing around half the global Covid death toll is rest home residents, it should be obvious that the “inoculum dose / severity of illness” hypothesis demands urgent attention to the aerosol buildup risk in these environments. NZ’s fools luck might not last forever, and it is a plausible hypothesis that high inoculum doses are a factor in “breakthrough infections” among the vaccinated. Posting a short essay discussing this possibility is what got me permanently banned from Medium.com.
Delta is likely to sweep through NZ at some point, and we’ll need to get everything right and use all resources to get through this. If we don’t we’re facing daily levels of around 600 people in hospital with Covid, based on Israeli and UK data – and we barely coped with 40 during the current outbreak.
Suggestions, starting with public health messaging:
1) Double masking
Cloth-over-surgical masking works about twice as well as either alone, and about as well as an N95/P2. New Zealanders will want to know this; tell them.
Relative effectiveness per CDC:
No mask – 0%
Cloth mask – 51%
Surg mask – 56%
Cloth mask-on-surg mask >90%
N95/equiv – 95%
https://www.cdc.gov/mmwr/volumes/70/wr/mm7007e1.htm
2) Mask reuse
see https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/decontamination-reuse-respirators.html
Reuse is not ideal, but we may have no choice.
3) The inoculum
‘Less virus, less disease’
It’s a tenet of infectious disease teaching that a smaller inoculum usually produces milder illness – fewer presentations, fewer hospitalisations and less death. If the public knew fewer viruses inhaled meant less severe illness, they’d be more likely to double mask, ventilate, and avoid high-risk indoor settings
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3649975
3) Formally walk back old incorrect messaging
An agency willing to admit its errors shows integrity and humility, and engenders trust.
The MoH should state that some of its old messaging was wrong, and clear up any confusion by issuing clear advice that Covid mainly spreads through the air, and that the MoH had exaggerated the danger of masks relative to the benefits. It should do this at the media standups – not just by quietly changing a part of the MoH website.
4) Get healthy – (‘get in shape for Covid’?)
Tell people it’s likely that covid will spread through NZ at some point.
It’s getting a bit late now, but there may be time for some people to shed comorbidities – obesity, and to some extent, diabetes and hypertension.
5) Early treatment
The PM and DGoH have said they’re looking at monoclonal antibodies – good but expensive and unlikely to be widely available.
Why not set up a nationwide RCT of, say, five repurposed, safe, inexpensive agents that have shown promise in small RCTS, with one placebo arm, so that patients have a 5/6 chance of a potentially-effective treatment. Offer this to patients newly diagnosed with Covid; let patients enter via their GP or primary healthcare provider. Analyse subgroups defined by age brackets and comorbidities.
We can’t afford to snigger at repurposed drugs, nor to make inflated claims for them. The emotion and tribalism around early treatment has to be replaced with cold logic, critical appraisal, and good judgement around cost, risk and benefit.
6) Refresh the MoH’s Technical Advisory Group
The TAG argued that mass masking was unnecessary, and rejected suggestions that Covid is airborne. NZ was one of the last countries in the world to adopt mass masking (the TAG even wrote a paper arguing against mass masking as late as June 2020)
The TAG was also very late to accept the importance of airborne spread, and the MoH only amended its website advice the on July 22nd 2021 – four months after the WHO.
IMO the TAG has dogmatically followed faulty WHO advice, and ‘what other countries are doing’, with a clear bias towards Western countries.
These bad calls have cost NZ – proper recognition of airborne spread might have lead to earlier and better protocols in MIQ, eg recognition that lifts rather than lift buttons are a hazard, and installing floor-to-ceiling barriers between public spaces and covid carriers in MIQ.
The TAG’s conclusions may have been driven by mask shortage, and in particular N95 shortage. But the evidence must drive the conclusions, not vice versa.
There are HCWs in NZ who by considering east Asian approaches, reading the literature, and thinking for themselves, have been right and early about every important controversy in Covid. Why not add them to the TAG?