Besides HBoV detection in respiratory samples and feces, HBoV DNA was also found in serum/whole blood [28, 59, 29] and one study reports detection in urine [70] . As there are no currently established methods to detect HBoV particles, it remains unclear if the detection of HBoV in serum indicates viremia or if HBoV targets blood cells. Parvovirus B19 infects erythroid progenitor cells in the bone marrow [2] , but HBoV DNA was not detected in bone marrow of HIV (human immunodeficiency virus)-infected and HIV-uninfected individuals, while parvovirus B19 was detected in both groups [71] .