Another highly pathogenic avian influenza (HPAI) virus is marching across Western Asia, Europe, and North Africa, killing domestic flocks and a number of wild birds, from India in the east to the Atlantic Ocean in the west.
This is the 4th wave of HPAI to sweep across large swathes of the globe in the past 11 years. The culprit this time around, an H5N8 virus, appeared in India in October and the Mediterranean basin in November 2016, leading so far to the deaths of hundreds of thousands of domestic birds and dozens of wild birds from over 30 species.
A potential silver lining to this unfolding story is that this particular H5N8 virus was first detected 4 months earlier, from a lake on the Mongolian-Russian Federation border. Prompt reporting of the find led to warnings by experts of a high likelihood of spread to exactly those regions affected so far.
Was the early warning a lucky break, or have we learned enough about HPAI epidemiology to make such predictions routine? The answer is a bit of both.
Laboratory procedures for working on dangerous pathogens has changed significantly over the past 40 years. Randal J. Schoepp, James Gathany
Pathogens are maintained in laboratories around the world for many reasons. They can be used to develop vaccines, to provide materials for diagnostic tests, or to study genomes, offering clues as to how pathogens may evolve so that we are better prepared to deal with them.
There is debate within the scientific community as to exactly what kinds of research should be done on especially nasty organisms commonly called Potential Pandemic Pathogens, such as the deadly SARS respiratory virus or highly pathogenic avian influenza viruses. Some believe the risks of escape, though small, are not worth taking as an accidental release could sicken or even kill millions of people, animals, or both.
Storks on migration over Haifa, Israel. Several individuals of this species were found in this area carrying a particularly virulent form of West Nile Virus from Europe in 1998. David King
Migratory birds move hundreds to thousands of kilometers twice a year, often spanning continents. As they share certain diseases with people, it is not surprising that birds are frequently blamed for transporting these diseases around the world. But while birds are undoubtedly implicated in the geographic expansion of some emerging diseases, the more interesting question is why it doesn’t happen more often, given the hundreds of millions of birds on the move.
A new avian influenza virus now rivals H5N1 as a candidate for the potential cause of a human pandemic one day. H7N9 first appeared in people three years ago and shares many characteristics with H5N1. But some key differences make this newer virus more difficult to keep tabs on as it circulates quietly through poultry flocks.
Villagers in Uganda bringing their chickens for avian influenza testing, 2009 Stephanie Smith
We don’t hear much any more about fears of an avian influenza pandemic sweeping the world. But the unique characteristics of avian influenza viruses and their expanding global presence make them as likely as ever to acquire the ability to thrive in people. This post and the next explain why these viruses are different and what can – and cannot – be done to stop them.