CDC: Mallards and Highly Pathogenic Avian Influenza Ancestral Viruses, Northern Europe

This paper is like many others in the avian influenza literature on wild birds.  Although it makes a very compelling argument for avian influenza surveillance in wild birds, and provides important information on the genetics of influenza isolates, it neglects to provide a numerator (how many birds had the virus) or denominator (out of how many birds were tested).

Risk is estimated (in its simplest terms) by the probability an event will occur, times the magnitude of the event once it occurs.  Without numerator and denominator information, it is impossible to estimate the first part of the risk equation (the probability an event will occur).  This information is critical to developing risk management systems.

Damien