Avian influenza and bioterrorism
At the tail end of the Fall 2011 semester, a fascinating report popped up in the medical literature that was picked up and widely reported in the popular press. Researchers at the Erasmus Medical Center in Rotterdam, and at the University of Wisconsin-Madison, reported their findings about the relative virulence of avian influenza (H5N1). The research, funded by the US National Institutes of Health, was to be published in the journals Science and Nature, however a national advisory panel (the National Science Advisory Board for Biosecurity) has asked the journals to withhold key details of the reports.
What the researchers did was not particularly novel. They utilized a virulent isolate of influenza virus which is poorly transmittable to humans. However, when humans acquire the virus from birds, the disease has an approximately 50% mortality rate which is several orders of magnitude higher than that observed for the 1918 worldwide pandemic influenza outbreak. So far, approximately 600 people have contracted this isolate of influenza since it was first identified in 1997. That low incidence figure drives home the point that this is not currently a significant pathogen of humans, however the great fear is that it could develop through random mutation the ability to more easily infect and be transmitted between humans. The high mortality rate then would be a calamity.
So this is where the current research of these two groups comes into play. They were both examining the determinants that affect virulence of H5N1 influenza. This is a common approach in infectious disease research: you take a given isolate of an agent, you make a genetic change in the pathogen, then you introduce it into a susceptible host and see if virulence has been affected. If you produce a pathogen with diminished virulence, then you have a potential way of attacking that pathogen in an infection, by developing a drug or other therapeutic agent to produce that might diminished virulence in the patient.
On the flipside, you could also potentially produce a pathogen with increased virulence with this approach, and this is what the two research groups have reported. On the surface, one might argue that little medical benefit might be obtained from this approach, and indeed an editorial comment in the New York Times recently made this statement:
But it is highly uncertain, even improbable, that the virus would mutate in nature along the pathways prodded in a laboratory environment, so the benefit of looking for these five mutations seems marginal.
This is patently wrong, and shows an incredibly naive view of the danger posed by the evolution of viruses in nature. Recombination of viruses will occur, and random chance will undoubtedly produce mutations similar to the ones made in the laboratory. The recent movie Contagion had this incredibly chilling line in it:
We don’t have to weaponize bird flu; the birds are already doing it.
Now, we see where the most significant medical benefit is in this research, and why it is essential that we continue with it. By understanding what makes a pathogen more virulent, we will have the tools to predict when this is occurring in the wild, and allow us to be prepared for that inevitable pandemic outbreak. It is a given that influenza outbreaks will continue, and we can demonstrate in the laboratory that we can make a more virulent pathogen. Nature, on the other hand, has infinitely more time and genetic diversity that we do in our labs, and is going to accomplish the same thing.
I was having an argument with a colleague the other day over this controversy, and she took the position that the report should be suppressed, due to the danger of accidental release or purposeful release by terrorists, and that I was perhaps naive in my assertion that medical research is inherently without moral judgement (“Not everyone is ‘Mary Sunshine’” were her words to me.)
My position in contrast is “That Ship Has Sailed.” The full nucleotide sequence of Variola major (smallpox) is freely available on Genbank, and although there has not been a case of smallpox in over 3 decades, that infectious agent can be reconstructed using in vitro techniques in a modernly equipped laboratory. We live in an age where we can manipulate microorganisms rapidly, and it doesn’t require the resources of a massive university laboratory to do so. Consequently, it is imperative that we work diligently to understand what makes a microorganism pathogenic, first so that we can begin to develop therapeutics for disease, and second so that we can see it coming when the outbreak inevitably occurs.
Posted on January 13, 2012, in Danger danger danger!, Death from the skies, Rant and tagged National Institutes of Health, National Science Advisory Board for Biosecurity, New York Times. Bookmark the permalink. 3 Comments.