JOHN DWYER. There is still a lot more that needs to be done to minimise harm in Australia from COVID-19.Mar 19, 2020
Australian governments are taking a “measured approach” to minimising the impact of the COVID-19 epidemic adding new tactics/restrictions as the numbers grow. Far better to use all available measures now to minimise that growth.
As would be true for many, I was emotionally distressed by vision from Italian hospitals in which exhausted doctors and nurses were in tears as they walked through corridors where lay dozens of critically ill patients in need of ICU care. Some patients where in tents in a parking lot. No attempt would be made to treat patients over 80!
This could happen here. Australians over 65 (there are 4 million of us) are most vulnerable, especially if they already have significant medical problems when infected. Now that we have had a chance to study data from the worst effected countries in the Northern hemisphere we know we could expect a fatality rate of 15% for this cohort. In part due to the biggest weakness in our health system, a lack of effective strategies for disease prevention, we have very many of us struggling in later life with hypertension, heart and lung disease, obesity, and diabetes. Care for such individuals consumes most of our health budget.
Disease modelling tells us two things, (1) applied simultaneously, harm reduction tactics can decrease the infection rate and (2) that this achievement will take many months. Clearly the harmony and rhythm of normal life is lost to us for 2020 and control of this epidemic must be all consuming. We can and will recover from all the distressing flow on effects on travel, education, business, budgets, etc but for now we need an informed and disciplined community response to help each other get through this epidemic. The signs are good that Australians have embraced this message.
There are three major programs in our response to COVID-19, (1) detection and isolations of those infected, (2) “social distancing” with all its ramifications and (3) protection of our health workforce and hospital preparedness for the inevitable demand for care from the seriously ill.
Detection and isolation
It’s these issues where we find Australia struggling, we do not have the capacity to do anything like the number of tests we should be doing. At a time when we should be expanding the testing program our Chief Medial Officer writes to our GPs asking them to order fewer tests. Why can’t we do more? Well, there is world wide demand for the reagents needed for the tests. The reagents needed (which are used in a number of other tests) are being sought by our Government and private pathology providers. The good news is that Roche pharmaceuticals has made available testing kits that will allow us to do about 100,000 tests. So far we have performed about 80,000 tests in Australia and with the growing number of infections being detected I fear these new supplies will still mean test rationing.
To understand the need for greater testing capacity, consider the following. Within a few hours of being infected with COVID-19 virus it is being shed into our nasal and respiratory secretions. The viral load in such secretions continues to increase for between 3 and 5 days before symptoms (due to our immune system responding) develop. All this time the virus is readily detectable. All this time as the virus is transferred to solid surfaces by hands that have been contaminated when brought to our face or become airborne, we are infectious. We are more infectious naturally as the viral load increases. When we start to cough and have a “runny” nose we are most dangerous. I was surprised on the weekend to hear our Chief Medical Officer suggest that we only became infectious 24 hours before we developed symptoms. This is not the case as is highlighted in WHO documents re COVID-19.
However matters are more complicated than the above would suggest as many people shedding virus have only minor or indeed no symptoms. Studies in South Korea revealed that the major source of infection that caused so many deaths among the elderly, was infected, asymptomatic, virus shedding children! Being comfortable with regimens that require two weeks of self isolation or, in the case of a proven infection, self quarantining to protect the community is also too arbitrary, Testing has documented many cases where infected individuals are still shedding virus three weeks after infection. This is why WHO and the CDC in the US tell us that best practice requires us to test those infected before allowing them to return to work and more normal living.
Then we have the very blunt instrument the government introduced on the weekend that requires every one coming home to Australia from everywhere to self-isolate for two weeks. Same instructions if you return from New Caledonia with no cases of COVID-19 or from the UK with its hundreds of cases. If we had sufficient tests and infrastructure available how much better would it be to test people four days after arrival (that is being very conservative) and allowing individuals with a negative test to resume normal activities. My point is that the epidemic should be managed with objective data (test results) not “well in most cases————-”
The other tool that is urgently needed is an assay for the development of antibodies to COVID-19 after infection. Such tests are available and being used in Singapore and China and are being developed here. Such tests allow one to diagnose infection and tell us how well our immune system has responded. We can learn if, post-infection, we are immune to COVID-19 and for how long. Shortly after most viral infections we make antibodies of a type designated as IgM (shorthand for Immunoglobulin M) that can bind to the virus and stop it entering cells. This type of antibody is short lived and as the immune response matures, we switch to making “IgG” which is often produced for months or even years endowing us with immunity to that particular virus. We need data on these responses in the majority of people who have been infected with COVID-19. Such data is coming and it’s of vital importance.
You may have seen significant publicity about the idea of letting the COVID virus spread in the community as most people will recover and as more people become immune (“ herd immunity”) the virus will have too few susceptible targets to survive. This is truly a terrible idea both scientifically and ethically and it is distressing to see Holland accept this as their official strategy to fight the epidemic. We don’t even know yet if recovery is associated with long lasting immunity. The death, suffering and total destruction of health services involved would be catastrophic. While we focus on the over 65 age group because they are more susceptible to a fatal infection many young people have died or suffered a very severe illness when infected.
Far more interesting is the possibility that we might use one of immunologist’s greatest tricks. This involves taking plasma from individuals who have recovered from an infection, harness the antibodies therein and provide them to people with an acute infection. Reports from China say they are onto this for COVID-19 and initial results are “encouraging.”
This epidemic has totally upended the normal harmony and rhythm of our lives and will do so for many months to come. Attempts to minimise the damage done to us by COVID-19 must necessarily dominate our energies and activities. It is so difficult to implement, but keeping away from each other is our major harm reduction strategy. There actually is good science behind the recommendation for distancing to involve a separation of at least 1.5 metres. The ramifications are almost endless but I wish to comment on some matters that I feel are being inadequately addressed.
How ridiculous (and dangerous) to have the elderly given a special time to congregate and shop at supermarkets? Clustering the most susceptible makes a mockery of social distancing. TV footage of large numbers of “oldies” cheek by jowl is distressing. On the same tack supermarkets must limit the number of people in their stores at any given time so that social distancing is possible. Every second self checkout bay should be deactivated. Food shopping is probably the activity that is most resistant to our “1.5” rule.
Another major problem involves crowding on public transport. With many working from home pressures may decrease but crowding (especially if standing) on trams, buses and trains provides a significant opportunity for cross infection. Numerous studies have shown that being a commuter in winter gives you a six times greater chance of becoming infected with the influenza virus!
Disease modelling, now more accurate as our unfortunate experiences mount, tell us that there is no chance that this epidemic will be under control this year. President Trump’s assertion that all will be well by August is as ill-informed as usual. In this turmoil of uncertainty where certainty can be made available it would of great help to a troubled populace. The last minute cancellation of the Victorian Grand Prix caused much frustration and hardship. It is unthinkable that the Olympic Games could be staged normally in 4 months. Yet the Olympic committee refuses to accept that reality.
Sound clinical advice tells us that we should not close schools if possible. It’s possible to educate children at home though best practice will need to evolve but being at home will be associated with more children in shopping centres etc, more interactions with older people and remember, children can be well but very infectious. The necessary desertion of the workplace to care for our kids would be economically challenging and would see many in our health system unavailable at a time when they are likely to be most needed.
The anticipated scenario for our public hospitals this winter is truly scary. We struggle every year to meet demand. Now imagine that we have a bad influenza winter. This is highly likely given the northern hemisphere experience in 2019. We already have 13,000 cases of influenza reported in Australia since January 1. In such winters we typically have almost 30,000 admission to hospital with many hundreds needing ICU care. Imagine trying to manage that scenario with a huge demand for care from people infected with COVID-19? We must make every effort to have less medical and hospital time taken up with handling Influenza infections. Our major tool for so doing is vaccination and I feel that we should be bringing forward the immunisation schedule, (normally mid April), asking people to get vaccinated as part of their contribution to handling our COVID-19 epidemic and, for this year, making vaccination free to all as a sign of how important it is to pursue this strategy.
Professor John Dwyer, Immunologist and Emeritus Professor of Medicine at UNSW.