Bird flu has forced the destruction of almost 160,000 turkeys on a poultry farm in Suffolk, but we should hardly be surprised that the virus involved was the much dreaded H5N1 form of the disease. The world has been on high alert for any appearance of this pathogen for some years, given the potential but as yet unrealised risk it poses to humanity.
Last year we watched news broadcasts with alarm as the virus pursued its relentless march west from its origins somewhere in the Far East. It provided a macabre sort of travelogue as the H5N1 virus appeared in wild bird populations in one far-flung country after another before finally reaching continental Europe and eventually Britain. The typical reportage referred to the "deadly" bird flu virus, but in reality, this virus remains deadly only to bird populations and not to humans. The H5N1 strain has yet to mutate and make the jump into human populations, which would allow human-to-human transmission.
This viral strain has yet to be detected in Ireland but its discovery here is only a matter of time. We can no more block its arrival than stop the flight of wild birds as they migrate on the warming spring air to nest on our shores. These viruses are a constant feature of life. Yet it is only prudent that the focus of governments across the EU, including our own, remains firmly on the potential threat posed by H5N1. This pathogen has proved itself deadly, killing more than 160 people and with a very high death rate after the disease is contracted. Its presence in the wild increases the risk that a chance exposure of a sick bird to a pig or human coincidentally suffering with influenza will cause the viral mixing and a consequent mutation that allows an avian virus to jump the species barrier and become infectious for humans.
The great influenza pandemic of 1918 was triggered by an avian flu virus that mutated to allow human-to-human transmission. It killed somewhere between 20 and 40 million people worldwide over a two-year period. We have had a succession of flu pandemics since, although not on the same deadly scale, but health officials tell us that we are now long overdue an influenza outbreak. The great fear is that the H5N1 strain could be the viral source for a fresh pandemic, particularly as it is new to our immune systems. There is little or no natural immunity against the organism among the wider community.
The Government here has taken on board all the advice being given by the EU in relation to human safety. An expert committee oversees and gauges the changing picture of risk and officials in the various departments keep in regular contact with their counterparts in the UK and the rest of the EU. Antiviral agents and potential vaccines are also stockpiled should the unthinkable happen and a human pandemic spring from this virus, although there are no signs of that happening at the moment. It is a time for cool heads and prudent planning in the face of a theoretical but not impossible danger.