Why we need to beware of flying viruses
Pat Hanlon says we should not over-react but that some travel restrictions may soon be necessary
Beware flying viruses
As if we all don’t have enough to worry about at the moment, we now have a further concern thanks to an outbreak of swine flu, a disease that the World Health Organisation has declared a pandemic, the first for 40 years.
Health officials in many different countries have issued various pieces of advice on how best to combat the spread of the disease.
There is a broad measure of agreement on the wisdom of catching coughs such as regular washing of hands and isolating people displaying symptoms but there is no universal agreement on the desirability or otherwise of travel restrictions, including restrictions on air travel. So, to begin with, is the swine flu outbreak sufficiently serious to warrant any such restrictions?
The WHO recently reported the number of confirmed cases as having climbed to 27,750, including over 140 deaths. These are worldwide figures; and, as yet, they indicate a very low incidence in relation both to previous pandemics and also to annual occurrences of seasonal influenza.
The latter are responsible for the deaths of up to 550,000 people a year with 12,000 in Britain alone. In terms of the proportion of infected people who died, the bird flu epidemic of 2005 and the SARS (Severe Acute Respiratory Syndrome) near-pandemic of 2002-03 were extremely lethal, but fortunately were contained before the number of cases grew into millions.
This was not so with the Hong Kong flu pandemic of 1968-69 which killed 1.4 million people and the ‘wild ducks’ Asian flu of 1957 which led to the deaths of around ten times that number.
The most catastrophic experience of all was the 1918-20 Spanish flu pandemic which caused the deaths of 50-100 million people. Ominously, the virus in Spanish flu was of the same sub-type (HINI) as in the current swine flu; another potential parallel is that Spanish flu started as a fairly mild outbreak at this time of the year before mutating into something far more serious during the following autumn.
It is to be hoped that history does not repeat itself but health authorities are absolutely right to take precautions. The question is whether transport authorities should do the same.
A couple of months ago, US Vice-President Joseph Biden sparked controversy by suggesting people should respond to the swine flu threat by avoiding air travel, mass transit systems and confined spaces generally.
The airline industry was quick to react by saying that this would amount to a disproportionate response at this stage. In any event, a number of countries introduced travel restrictions, especially on routes to Mexico and to affected parts of the US. A number of multinational companies have also restricted the business trips of their employees.
The official view of the WHO is that ‘‘imposing travel restrictions would have very little effect in stopping the virus from spreading, but would be highly disruptive to the global community’’.
The WHO says the focus should be on minimising the impact of the virus through rapid identification of cases and providing patients with appropriate medical care, rather than stopping its spread internationally. This position, the WHO maintains, is validated by the records of previous pandemics.
Air travel clearly played no part in the propagation of Spanish flu, since there were no air passenger services in 1918. Surface travel had an important role, insofar as the infection was spread by troops returning from the trenches of the First World War.
There may be little to suggest that air travel was a major factor in the 1957 and 1968 pandemics but since then, over the past 40 years or so, there has been around a ten-fold increase in air travel and it was remarkable, with the current swine flu, that only a few days passed since the original news of the outbreak in Mexico before cases were suspected as far away as New Zealand.
During the SARS epidemic, attempts were made to impede the spread of the disease. Travel to SARS hotspots was curtailed; air filters on aircraft were changed frequently; disinfectant was sprayed on board flights arriving from places known to have had outbreaks and passengers were monitored for signs of fever.
The latter was found to be worthwhile because, with SARS, passengers shed the virus (to infect others) only after symptoms appear. But with swine flu, passengers can be shedding the virus before being aware of any symptoms, so that one person on the aircraft can infect many others before he, she or anyone else knows he or she is unwell.
This makes swine flu more difficult to contain than was SARS. In any event, too much should not be expected from air travel restrictions. Studies have indicated that border controls will only produce significant benefits if they are more than 90 per cent effective; even in that case, the most they can do is to slow the spread of disease by a matter of few weeks. But if the swine flu virus were to mutate into something more lethal than has been experienced so far, the slowing effect could be vitally important for developing and distributing an antidote.
One observation of how a decline in air travel can delay flu came in the US in the aftermath of the terror attacks of 9/11 when a lot of people decided not to fly because of fears of terrorism.
The onset of normal seasonal flu was put back by two to three weeks. In itself, this was a benefit but one to which a high price was attached: with more people driving instead, there was an estimated increase of more than 1,500 in the number of road accident fatalities over the year following 9/11. Ordinarily, air travel is one of the safest modes of transport.
Steps to restrict air travel should not be taken lightly, not simply because of effects on the airline industry, but also because of some potentially adverse implications for public health generally.
But if the present virus develops into anything remotely resembling the horrendous virus which visited the world in 1918, then some air travel restrictions may have to be implemented quickly.
Pat Hanlon, a senior lecturer in industrial economics at the University of Birmingham’s School of Business, is the author of
Global Airlines: Competition in a
Transnational Industry
