The current Christmas season here has, by many anecdotal accounts, been heavily virus-laden. One of the more often-heard responses this year to the timeless question of "how did you get over the Christmas?" will include some reference to one or more family members being down with "the flu". Yet there has been no scientifically-confirmed sighting of any of the several influenza viruses which may sporadically visit this island. What assails many Irish homes at the moment is more likely a variety of other, milder, viral infections including some relatively severe common colds.
Meanwhile, the attention of experts in influenza has been directed towards Hong Kong where there has indeed been a small but most unusual outbreak of what just might prove to be a new variant of the disease in humans. There have been just 13 cases and a further nine suspected cases - not an epidemic by any standards - and four deaths from an influenza apparently caused by a virus known as A influenza H5N1 which until now has only affected birds. It was first identified in 1961 when it was found in sick or dead terns in South Africa. It has not previously been shown to afflict humans and, in all but one of the current 22 cases, it has shown no signs of being transmissible between humans.
The one exception in the current outbreak is the possibility that a carer of one of the children who contracted this avian influenza may have caught the disease from that child's body fluids. All the others (including the child) had been in close contact with poultry and are presumed to have caught the influenza directly from infected birds. Thus, all the poultry in Hong Kong have been slaughtered over the past couple of days and further imports from southern China have been stopped until further notice in an effort to remove the source of the virus.
What gives rise to concern is that this avian influenza virus seems now to be capable of transmission to at least a small number of humans and that it may have further been transmitted from one human to another (albeit in what Hong Kong's medical director described as an apparently very inefficient method of transmission). The deeper scientific concern is that, after nearly 30 years of apparent confinement to birds, the virus might have mutated in some way (as influenza viruses are wont to do) to make its transmission from birds to humans and from humans to humans more feasible and more frequent.
The Hong Kong authorities appear to have taken commendably firm and extensive action to try to quell the current small outbreak, and such agencies as the World Health Organisation and the Centres for Disease Control in the United States are already actively involved in further research and in the preparation of a protective vaccine. Such a vaccine is reportedly ready for manufacture but the order to start manufacturing it in bulk has not yet been given. It is to be hoped that no such order will prove necessary and that the possibility of a pandemic of avian-human influenza will prove as illusory as Ireland's Christmas "flu".