My family was gripped by a TV drama in the 1970s called Survivors. In the show, most of the world’s population is annihilated by an accidentally released virus, which was the creation of Chinese scientists. The virus is hyper-virulent, killing 4,999 of every 5,000 people it infects. It is also hyper-transmissible, spreading between people with ease and traversing the globe with infected people on passenger jets. The series, which followed the fate of those few who survived the outbreak, and the development of a post-apocalyptic society, was more akin to Cormac McCarthy’s The Road than, say, Steven Soderbergh’s 2011 film Contagion, which depicts societal breakdown during a killer virus emanating from Hong Kong.
Mankind has always feared pestilence. After all, for most of humanity’s history, infections killed nearly everyone. Only in the past century or so have we been able to defeat an increasing number of the germs that afflict us and live long enough for our hearts to go wrong or our cells to become cancerous.
The occasional appearance of new germs into human populations created “epidemics”, if within a limited geographical area, or “pandemics” if they spread globally. Millions of people became infected simultaneously, often dying as their immune systems struggled in the face of new pathogens. Plague, for example, caused by bacteria and spread by fleas, was probably transmitted to humans in the early 14th century, when the normal rodent hosts of the bacteria moved to urban centres in north-eastern China as global warming turned their grassland habitats arid. Within a few decades, the plague spread widely through traders travelling the Silk Road. It killed a third of Europe’s population from 1346-1353.
In 2020, we are once again gripped by the news that a virus, previously unknown to mankind, which appeared among a small group of people who visited a fish and wild animal market in Wuhan, China, is now spreading globally. The Wuhan virus (2019-nCoV) belongs to the same “coronavirus” group as Sars (severe acute respiratory syndrome virus) and Mers (Middle East respiratory syndrome coronavirus).
Sars emerged in southern China in 2002 and spread rapidly, ultimately killing around 10 per cent of the 8,273 people afflicted. It triggered a global effort to contain its spread, including airport closures in the cities most affected by the disease. Sars appeared suddenly, entering humans via aerosols created by infected civet cats sold as food in rural markets. The civet cats themselves contracted the virus from bats.
Mers, as its name suggests, was first identified in Saudi Arabia in 2012. To date, around 2,500 cases have been reported and around a third of those diagnosed with the disease have died. All cases are associated with the Middle East and either occur there, or among people who have visited endemic countries. Camels appear to carry the virus and are suspected to be its reservoir, although camels probably also initially contracted the virus from its natural bat hosts. How it is transmitted to humans is not clear and its disease’s spread has been limited. Like Mers and Sars, the Wuhan virus causes problems in the respiratory tract and deaths have resulted from pneumonia.
The deadly Ebola virus kills around half of those who are afflicted. Ebola, which is transmitted through body fluids, causes victims to bleed to death from the inside. The 2014-16 Ebola epidemic in West Africa killed over 11,000 of its 28,000 or so victims. The virus only occasionally reaches humans from its normal bat hosts.
The swine flu epidemic of 2009-10, caused by the so-called H1N1 strain of the flu virus (the H and N types relate to molecules on the virus’s surface) caused much concern. However, although it spread widely (up to one in five of the world’s population were infected) it was nowhere near as virulent as early reports in Mexico suggested. Around one in 5,000 victims died, similar to normal annual flu death rates.
However, we remain terrified of other flu strains, not least the H5N1 and H7N9 varieties that first appeared in humans, having been contracted from birds, in 2003 and 2013 respectively. H5N1 has killed over 60 per cent of its 893 victims and H7N9 around 400 of the 1,000 or so affected so far. Neither virus transmits readily between humans. But flu viruses mix and match their genetic material with ease and the real risk lies in a hybrid virus, possessing the hyper-virulence of H5N1 and the easy spreading features of H1N1. Millions will die fairly swiftly should that virus be born.
The Wuhan coronavirus is spreading quickly. Having first been reported on 31 December last year, as of 27 January nearly 3,000 confirmed cases were reported with more than 80 deaths. That’s a fatality rate of just below 3 per cent. Neil Ferguson, a leading epidemiologist at Imperial College in London, has built computer-based models to track similar viral diseases and calculates actual numbers could be 100,000 or more, with many people suffering little more than a common cold, yet still able to transmit the disease.
Almost all the cases reported outside China have been in people who had recently travelled to the country, but it seems inevitable the spread will continue, and lessons learned from previous pandemics should be put in place now.
In spite of accusations of secrecy and cover-ups, the Chinese response has been extraordinary. In just nine days, scientists had used genetic sequencing techniques to identify the virus. The travel bans, incredible efforts to erect hospitals in days, galvanisation of medical help, mandatory mask-wearing, and so on, are no mean feat.
But with millions of people trapped in cities where entry and exit is prohibited, socio-economic considerations and public unrest will ensue. Global efforts to assist China in dealing with the crisis will test us to our limits. As with Sars, Mers, Ebola and bird flu, 2019-nCoV isn’t going to kill 4,999 of every 5,000 people it infects, nor is it going to spread as rapidly or far as the fictional virus of Survivors. As well as remembering our capacity to intervene, we can be confident that the apocalypse isn’t here just yet.
Michael Barrett is professor of biochemical parasitology at the University of Glasgow
This article appears in the 29 Jan 2020 issue of the New Statesman, Over and out