Waiting for the big one: a new flu pandemic threatens

Here we go again. A new strain of Bird Flu has emerged which has so far infected more than 1,600 people and killed more than 620 in China. Are we about to be confronted by another pandemic of Bird Flu?

This new strand of Bird Flu, labelled H7N9, seems to be much more virulent than previous strains and has so far killed 38% of those it has infected many who had been hospitalised. Most disturbingly, it has been found to pass easily among animals and is causing severe disease in people who have had the misfortune to become infected.

This particular strain of the virus has been circulating in China over the last five years causing severe outbreaks of disease in people and birds. Exposure to poultry in live bird markets seems to have so far been the primary source of infection among people in China.

Studies conducted in the USA and Japan have also found that this particular virus has developed the ability to spread and replicate in a wide variety of mice, ferrets and other non-human primates. Every day it seems we are faced by new and frightening news about Bird Flu.

Now we are being told that the influenza virus can jump from pigs to dogs and while this virus has yet to make the jump from dogs to people and while so far it does not involve the H7N9 strain there is every chance of this strain becoming involved. Just imagine a pandemic of virulent dog flu and the implications it might have for us.

Cast your mind back to 2009 when Swine Flu infected millions of people around the globe and killed more than 250,000. In Australia there were 37,537 confirmed cases and 191 deaths, while tens of thousands more suffered from the outbreak. In New Zealand 18% of the population was affected, resulting in more than 700,000 cases and 49 deaths. Maoris and Pacific Islanders were particularly at risk with the highest rates of infection.

Consider also the incredible scenes of panic and hysteria that this outbreak produced and the way people reacted, in particular doubting their government’s ability to protect them.

Currently there is considerable concern that this new pathogenic strain of Bird Flu could cause severe disease and a much higher death rate than experienced ever before. In 2013 the CDC in America produced a new vaccine based on the existing pathogenic strain but there remains considerable doubt about its ability to cope with the new strain of Bird Flu that has emerged and the CDC is currently working on producing a new vaccine.

The problem is, however, that to avoid pandemics, health authorities need to keep up with all the antigenic changes in Bird Flu and develop specific vaccines to match them. Unfortunately we are always one step behind as it takes time to develop and test a new vaccine and importantly we continue to underestimate the ability of such pathogenic viruses to mutate and develop new strains and spread to animals.

Bird flu has never gone away. Over the last couple of years there have been outbreaks of the disease among wild birds and poultry in more than 10 countries around the world, including South Korea, Hong Kong, Taiwan South Africa, Russia, Bulgaria and England. While these outbreaks have not yet been produced by the H7N9 virus it is perhaps just a matter of time before H7N9 spreads and begins to take its toll.

Winter flu breaks out every year in countries like Australia and New Zealand largely because the virus mutates and allows it to avoid antibodies we preserve from the previous year’s flu as well as often rendering the vaccine we have produced not that effective. But every so often an influenza virus arrives that is much more virulent and largely avoids the vaccine made from the previous years’ outbreak. In times of pandemics flu spreads like wildfire and not only targets the very young and the elderly but also younger adults.

While we may develop some degree of immunity when faced by ordinary flu, new strains such as H7N9 are much more deadly. It is a disturbing future for which we remain ill prepared.