Introduction to Techniques and Methodologies for Characterizing the Human Respiratory Virome.

There have been great advances in the methodologies available for the detection of respiratory viruses. Accompanying this, our knowledge surrounding the impact of these viruses has also made a great leap forward. We have come a long way from the once commonly accepted belief that the lower respiratory tract was sterile and that the detection of any microbial species must represent a breach in host defence and likely be associated with symptomatic infection. With the advent of molecular detection techniques and improvements in sequencing-based methodologies to make these tools more accessible and cost effective, we now know that there is an abundant and diverse ecosystem within the lower-respiratory tract. This chapter will outline the clinical impact of the human respiratory virome, techniques for sampling the lower respiratory tract, the evolution of the diagnostic tools available, and the current limitations in our instruments and knowledge in this area. The human respiratory virome is an exciting new area of research that will continue to grow with the aid of the methodologies outlined in the following chapters and the advent of even more efficient tools in the future.