Human bocavirus (HBoV) was discovered in 2005. HBoV has been detected in patients suffering from respiratory infections and gastrointestinal diseases, but a proof that HBoV is the causative agent in such cases is missing as it remains impossible so far to fulfil Koch’s modified postulates. The latter problem is caused by the fact that HBoV is difficult to propagate in cell culture and that no animal model is available.
Since HBoV infections are accompanied by co-pathogens in a very high frequency, it has been suggested that HBoV is a passenger rather than a pathogen in airway infections, despite the fact that HBoV causes a productive infection with viral shedding, viremia, and putative persistence in different organs. Although HBoV meanwhile was classified as an autonomous parvovirus rather than a Dependovirus like the Adeno-associated virus (AAV), there remains the possibility that HBoV infections depend on helper viruses or at least contributes synergistically to the clinical course of disease.
Does human bocavirus infection depend on helper viruses? A challenging case report. Virology Journal 2011, 8: 417 doi:10.1186/1743-422X-8-417
A case of severe diarrhoea associated with synergistic human bocavirus type 1 (HBoV) and human herpes virus type 6 (HHV6) is reported. The case supports the hypotheses that HBoV infection under clinical conditions may depend on helper viruses, or that HBoV replicates by a mechanism that is atypical for parvoviruses, or that HBoV infection can be specifically treated with cidofovir.