Healthy individuals may also have viruses in their blood.

If you have received a blood transfusion, or entered red blood cells, white blood cells, plasma, or other blood parts separately, you may also have entered a series of viruses.
A recent study involving blood samples from more than 8,000 healthy individuals using the Viral Population Genome Bank (virome) identification method found that 42 per cent of the subjects may contain 19 different DNA viruses (see reference).
collected blood samples from 8,240 individuals to determine genome sequences from which viral DNA sequences were identified.
about 5 percent of the resulting 1 PB (1 gigabytes) of sequence data does not match human DNA.
this section, a total of 94 sequences of different viruses were identified.
19 of them are human viruses.
the method does not detect RNA viruses, but reverse retrovirus that is integrated as a copy of DNA in the host chromosome.
the most common human virus identified by
is the herpes virus, including cytocytovirus, Epstein-Barr virus, herpes simplex virus and human herpes virus type 7 and 8, which can be detected in 14 to 20 per cent of individuals.
found a small virus with a ring genome in 9% of ---- the Anelloviruses.
other viruses found in less than 1% of the samples included papillomavirus, microvirus, polyomavirus, adenovirus, human immunodeficiency virus and human T lymphocyte virus (the 3d integrated into the host DNA).
75 other viruses detected may be contaminants from laboratory reagents or the environment.
these viruses, including sequences from non-human retrovirus, four different giant DNA viruses and a bee virus, were found in just under 10 samples.
these findings illustrate the importance of distinguishing real human viruses from pollutants.
identifying viruses in the blood is an important goal in ensuring a safe blood supply.
currently screening the blood of the available body for HIV-1 and 2, human T lymphocyte viruses-1 and 2, hepatitis C, hepatitis B, West Nile and Zika.
these viruses are pathogenic to humans and can be transmitted through the blood.
viruses, such as the ring virus and pegiviruses, a newly discovered virus in the yellow virus department, are present in most donated blood, but their potential for disease is unclear.
it is not feasible to reject the blood of a supplier containing any type of viral nucleic acid---- if we do, we will not have any blood supply.
need to continue to study the blood's viral population genomic bank (virome) to determine which viruses should be selected for the test of donated blood.
Human papillomavirus (17), Merkel cell polymavirus (49), HHV8 (3) and adenovirus (9) detected in this study may be transmitted in the blood and their presence should be monitored in future studies.
, the study only describes the DNA sequence of the virus, not the presence of an infectious virus.
blood supply can be easily screened by nucleic acid testing, it is important to determine whether an infectious virus is present.
if viral DNA is present in the blood, but the infectious virus has never been detected, there is no need to reject the blood based on the presence of certain sequences.
: Moustafa A, Xie C, Kirkness E, Biggs W, Wong E, Turpaz Y, et al. (2017) The blood DNA virome in 8,000 humans. PLoS Pathog 13 (3): e1006292.doi:10.1371/journal.ppat.1006292.