Living through a time of plague
High above the city, I contemplate the sea, the mountains and the evening sky. I can see planes coming into land in the airport and as the sun sets over the range, the hills turn gold, and the sky is hot with colour. Here in Cairns, Australia, we seem to be in our usual state of contentment.
But the sense of unease, of anxiety as the nation faces this uncertain foe lies just beneath the surface. We look with alarm at what is happening in Italy, where the beast has leapt the barriers. Our numbers are still thankfully low, but community transmission is occurring.
So what are the implications? What we know from the Chinese experience is that one infected person may transmit the virus to two others (with measles the R is 16). But our communities have never been exposed to the virus so natural immunity is negligible. The initial figures suggested that the distance the virus can leap from an infected person is 1.5 metres. In economy class that means four people. Some people who catch this may be asymptomatic, but can still transmit it. Most will have mild disease if anything.
But for the elderly and vulnerable it may be very different. The mathematical modelling depends on assumptions which are themselves in evolution. But I think it fair to say that there is a likelihood, acknowledged by government, that there will be a sharp increase in transmission over the next month, and most of the population may have been exposed to the virus in a year or 18 months.
In Cairns we have been working on infrastructure, ICU beds, ventilators, test kits, protective gear, and the myriad other necessities to deal with a sharp increase in the numbers of sick people. There are protocols being developed to receive, process and admit patients, as well as protecting health care workers. It is an expensive business and the Federal Government has just pledged two and a half billion dollars towards this effort across hospitals in Australia. Perhaps in a year an effective vaccine will be available. Perhaps by then a significant proportion of the population would have been exposed to the virus (only a small proportion of this exposed population will be tested using present technologies) and a degree of community immunity will have been developed. Transmission will then decline, and like the previous respiratory viral threats (H1N1, Zika, SARS, MERS) will disappear. But where to? Bats, civets, pythons. The poor plodding Pangolin?
Are animals the problem? Many of the remarkable tools of molecular biology have helped to develop new sciences. Phylogenetics is one of them. Measles, (let’s keep in mind this causes more than a 100,000 deaths yearly worldwide, despite good vaccines being available) evolved from the cattle rinderpest virus about a 1000 years ago. What about the common influenza A (HINI)? This “Spanish Flu” probably evolved close to that time from pigs, via birds. It caused 500 million human infections worldwide, 10% of whom died.
The flu virus is deceptively simple consisting of 8 strands of RNA. One method of replication of RNA is by an enzyme RNA polymerase which is prone to inaccuracy, and there is no back-up. So mutations occur frequently. There are two genes in particular which confer aspects of virulence and infectivity on the virus, HA and N and mutations at these points explain the changes. The original Spanish strain seemed to disappear after 30 or 40 years, to be replaced by others, but then has reappeared. It is this strain that mutates from year to year and place to place, and is the cause of influenza vaccines being far less than perfect in providing immunity. Bird Flu (H5N1 or Avian flu) emerged in 1997, and can be transmitted to humans and other animals. This seems to have disappeared, but the virus was lethal to humans, and is a continuing source of alarm to virologists and Public health physicians. Novel corona viruses are continuously evolving in bats, well shown in the months before COVID-19.
We are finding out how expensive it is to treat epidemic illnesses, compared to preventing them.
One of the pleasures of working in a major teaching hospital is the “Grand Round”. This is an institution held weekly for all hospital staff, and the most interesting presentations are given, usually by experts in their field.
Last month we had a remarkable presentation from a Cairns Hospital contribution to the International Medical Task Force to Samoa to combat their awful measles epidemic of late 2019.
In June of 2018 two small children in Samoa died immediately following the standard MMR vaccination. There was public outrage strongly pushed by the anti-vaccination lobby in Samoa, but also from Australia. Tragically the Samoan government went along with this, and vaccination ceased. It was shown subsequently that the vaccine was mixed with a solution of muscle relaxant which was stored in the vaccine fridge rather than saline. A tragic mistake, which eventually led to charges and a conviction. But the vaccination programme was not restarted.
The expected measles epidemic in Samoa began in September 2019, and rapidly reached crisis proportions. A remarkable international response led by Australia arrived in Samoa by early November. By the time the epidemic had been controlled 3% of the population of 200,000 had been infected with 83 deaths the majority in children. The epidemic was halted by a mass vaccination programme made compulsory by the government who declared a state of emergency to do this.
The Australian Emergency Response Team was led by one of our Cairns senior Emergency Physicians. At one stage it had an international force of over 150 people, doctors, nurses, technicians and logistics experts. They had to set up a Paediatric Intensive Care unit, and the team had to deal with the awful consequences of 83 deaths in a month, and the grief of parents who had to come in and remove their dead and dying children.
The team completed their mission as viral transmission ceased after the vaccination programme. The cost would have run into many millions of dollars. Senior members of government got it hopelessly wrong, with awful consequences.
Remarkably, there is a robust and powerful lobby against vaccination. This began to receive publicity after a famous paper published in The Lancet in 1998, which suggested a link between MMR, autism and bowel disease by Dr Andrew Wakefield, a London Gastro-Enterologist. He went on to publicise these associations and campaigned against vaccination. He was stripped of his registration to practise medicine by the GMC in England in 2010. He has since re-located to the US where his movement has support among the highest in the land.
Sri Lanka is a success story being declared measles free in 2019. Our good National Health Service ensures vaccination programmes are carried out. But it was also declared Measles free in 2011. So we can never relax with vaccination.
So what about COVID 19?
A hopefully effective vaccine may be six months or a year away. In the meantime health services worldwide have to prepare to treat large numbers of patients sick with the virus. Italy was unprepared. China seems to have turned things around. Restrictions on travel and gatherings are designed to delay the onset of the first wave.f wave of cases, and Australia seems to have achieved this while it is gearing up the resources required in Hospitals.
Are there any lessons to learn?
A very reasonable assumption is that this novel corona virus evolved in a Chinese wet market in Wuhan. Clearly the commercial exploitation and butchery of wild and farmed animals in proximity to human populations is a hazard. This should be subject to the highest standards. Despite the Chinese proclivity for exotic foods, this awful trade in wet markets mainly in China but also elsewhere in South-east Asia should cease. The next virus, and there is likely to be one, may be much nastier than COVID 19, unless we act to minimize these risks. Our pangolins, after all, are also precious
We have taken for granted the ease and lack of restrictions on international travel. Things may never be the same again. At its most basic is the requirement that people who are travelling must be seen to be immune or vaccinated against the “bugs du jour”. Perhaps a bar code rather than the old fashioned vaccination certificate.
Ultimately we rely on strong government. Even in democracies difficult choices must be made.
(The writer is Associate Professor of Surgery, James Cook University, Cairns, Queensland, Australia)