Human bocavirus in stool: A true pathogen or an innocent bystander?

Human bocavirus (HBoV) is a parvovirus that was discovered only a decade ago and currently includes four genotypes. HBoV-1 is predominantly found in the respiratory tract, whereas HBoV-2, HBoV-3, and HBoV-4 are mainly detected in stool. HBoV-1 is known to be associated with respiratory tract infections. In stool, the prevalence of HBoV (1-4) is similar between patients with gastro-intestinal symptoms and healthy controls in most studies. Furthermore, often other viruses are concurrently present. Both findings suggest that HBoV in stool is an innocent bystander rather than a true pathogen. Nevertheless, several gaps in knowledge on the role of HBoV in stool remain to be addressed. All studies were performed in primarily immunocompetent patients. The role of HBoV in immunocompromised patients remains unknown.