Human Bocavirus: A New Viral Pathogen

In this issue of Clinical Infectious Diseases, Allander et al. [1] report a study of the recently discovered human bocavirus (HBoV) in children hospitalized with wheezing. This study is a nice example of what is likely to be an increasingly common challenge and opportunity in infectious diseases: determining what diseases novel pathogens cause. HBoV was first described in 2005 after large-scale molecular screening for virus genome sequences led to its discovery in respiratory specimens [2]. Among the sequences identified were those from a novel parvovirus related to minute virus of canine and bovine parvovirus that was designated "human bocavirus." Because the virus sequences were amplified from respiratory specimens, the investigators hypothesized that the virus would cause respiratory disease, and they and others have since documented the presence of HBoV in 1.5%-11.3% of respiratory specimens obtained from patients with acute respiratory illness. Another new human parvovirus, PAR4, was