NEW YORK (GenomeWeb) – A study of blood transfusion recipients from the US and Europe has uncovered a new virus resembling both hepatitis C virus (HCV) and the human pegivirus (HPgV).
As they reported online in mBio today, researchers from the US and Senegal used sequencing to characterize viruses found in blood samples taken before and after transfusion in almost four dozen blood recipients sampled at centers in the US between 1974 and 1980 for the Transfusion-Transmitted Virus Study (TTVS).
Sequences from a hepacivirus- and pegivirus-related virus turned up in post-transfusion samples from two individuals, while follow-up tests on samples from hundreds more individuals who received blood transfusions US and Europe in the 1980s uncovered two more people who had the virus in their blood for months or years after transfusion.
While it remains to be seen whether the new virus — dubbed human hepegivirus 1 (HHpgV-1) — has negative health effects, the team noted that its results suggest the virus can be passed from one individual to another through the blood supply.
"HHpgV-1 is unique because it shares genetic similarity with both highly pathogenic HCV and the apparently non-pathogenic HPgV," first author Amit Kapoor, a pathology and cell biology researcher with Columbia University's Center for Infection and Immunity, said in a statement.
"People need to be aware of this new infection in humans," Kapoor noted, emphasizing the important of characterizing viruses that can be transmitted in the blood supply to ensure the safety of blood transfusions.
He and his colleagues noted that these and other efforts to tally up and characterize viruses present in the blood supply could improve blood screening and head off future transfusion-based disease transmissions.
"More than 30 million blood components are transfused annually in the United States alone," the study's authors wrote. "Surveillance for infectious agents in the blood supply is key to ensuring the safety of this critical resource for medicine and public health."
With that in mind, he and his colleagues used Illumina HiSeq 2500 sequencing to assess enriched viral nucleic acids in pre- and post-transfusion blood samples from 46 individuals tested at four American centers between July 1974 and June 1980.
Compared with the pre-transfusion samples, the team saw a rise in total viral reads in the blood samples taken from recipients after their transfusions.
When they focused on reads that didn't resemble known viruses, the researchers saw an unknown flavivirus in two post-transfusion blood samples, which they went on to sequence at greater depth.
The team unearthed two more HHpgV-1-positive blood samples when it tested additional samples from the TTVS and samples from 106 individuals tested longitudinally for a study of individuals with hemophilia and related blood coagulation conditions.
The latter program centered on eight American sites from 1982 and 1985, but was expanded to fold in four more centers in the US and four European centers between 1987 and 1990.
The team's phylogenetic analysis indicated that HHpgV-1 falls in the Flaviviridae virus family, which also contains species in the Hepacivirus and Pegivirus genera.
Both TTVS participants who tested positive for HHpgV-1 post-transfusion appeared to clear the virus within a few hundred days of infection, the researchers reported. In contrast, the virus persisted in post-transfusion blood samples from one of the individuals with hemophilia for nearly a year and a half.
The study's authors cautioned that "further studies are necessary to verify the presence of HHpgV-1 in the transfused blood and to rule out other possible [treatment-related] infection sources over this period."
Nevertheless, they noted that the new genome sequence data for HHpgV-1 "will be helpful in designing molecular reagents to study its prevalence, persistence, transmission, and disease association in humans."