No abstract

Human bocavirus is the second autonomous human parvovirus with assumed pathogenic potential. Other parvoviruses are known to persist and even integrate into the host genome, eventually contributing to the multi-step development of cancer. Human bocavirus also persists in an unknown percentage of clinically asymptomatic patients in addition to those with primary infection. The aim of the present study was to analyze the role of Human bocavirus in lung and colorectal cancers. Therefore, formalin-fixed, paraffin-embedded, archived tumor samples were screened for Human bocavirus DNA by PCR, Southern blotting, and sequencing. Positive tissues were further subjected to fluorescence in situ hybridization analysis to specifically detect human bocavirus DNA in the infected cells. In total, 11 of the 60 (18.3%) lung and 9 of the 44 (20.5%) colorectal tumors tested positive for human bocavirus DNA by PCR and were confirmed by sequencing and fluorescence in situ hybridization analysis. Thus, human bocavirus DNA is present in the nuclei of infected cells, in either single or multiple copies, and appears to form concatemers. The occurrence of these human bocavirus DNA structures supports the existence of the postulated σ- or rolling-hairpin replication mechanism. Moreover, the fluorescence in situ hybridization patterns inspired the hypothesis that human bocavirus DNA either persists as cccDNA or is integrated into the host genome. This finding suggests that this virus may indirectly contribute to the development of some colorectal and lung cancers, as do other DNA viruses, such as the human hepatitis B virus, or may play an active role in cancer by interacting with the host genome.

We describe a case of bronchiolitis associated with the newly detected human bocavirus (hBoV) in a child with a suspected Noonan syndrome. This is the first report of a bronchiolitis probably linked to hBoV that required intensive care while being accompanied by a congenital heart disease and a history of several episodes of severe respiratory symptoms.

Human metapneumovirus (hMPV) infections occur frequently despite high rates of perpetual seroprevalence for all age groups. Analyses of ϳ2,000 archived, randomly selected serum samples demonstrated that neutralizing capacities remain high, with a minor decrease for individuals over 69 years of age, leading to the hypothesis that reinfections occur because humoral immune responses play minor roles in the clearance of hMPV infections.