Human rhinoviruses: coming in from the cold

Rhinovirus infections cause at least 70% of virus-related wheezing exacerbations and cold and flu-like illnesses. Infections are also associated with otitis media, sinusitis and pneumonia. The annual impact of human rhinovirus (HRV) infections costs billions of healthcare dollars. To date, 100 serotyped HRV or 'classical' strains have been divided between two genetically distinct species based on subgenomic sequences, but many more, apparently novel strains remain un-characterized, circulating in unknown patterns and causing undefined illnesses. Until recently, the genomes of less than half the classical strains had been sequenced. In April 2009, the remaining classical HRV genome sequences were reported. These data will inform therapeutic development and phylogenetic analysis for this subset of HRV strains but should be viewed as one step in a long road leading to comprehensive HRV characterization.