We don’t know if it is going to be a significant cause of human hepatitis,” Lipkin told NBC News. Though it’s unclear how common the pathogen is, there’s no evidence that it has caused anyone harm, and half of those infected appear to have cleared it. The newfound virus’s genetic sequence shows that it has similarities to hepatitis C, which can cause serious liver damage, and to the harmless—and even helpful—human pegivirus (formerly dubbed hepatitis G). Amit Kapoor, a virologist at Columbia University led the team that identified the new virus—and which has named it human hepegivirus 1, or HHpgV-1—notes that many people understand that humans coexist with myriad bacteria that are not dangerous, but they don’t realize the same holds true for some viruses. As part of a search for novel human viruses, the group scoured blood samples from a cohort of 46 people that were collected before and after they received a blood transfusion between 1974 and 1980. “I thought if I want to know whatever is circulating and unknown these are the best samples,” Kapoor says. Based on later blood samples that were analyzed, both of these people subsequently cleared the virus, the team reports online today in mBio. An analysis of a different batch of stored blood samples, from 106 people who had received many blood products because they had hemophilia, found two more people who harbored HHpgV-1 sequences. “While this elegant and valuable work serves to emphasize the power of modern deep sequencing technology in identifying new viruses, the role of this new virus in liver and other diseases remains to be elucidated,” he wrote in an email. Almost every year, scientists identify a new virus in humans, Busch says, and some undoubtedly were spread through transfusions. “Are they recently in the human population or have they been around for a long time?”
– Scientists have discovered a new virus apparently transmitted through blood transfusions. Little else is known about human hepegivirus-1, or HHpgV-1, besides that it looks a bit like hepatitis C and the harmless and perhaps beneficial human pegivirus. "It is the first transfusion-associated virus that's been described in a long time," a researcher tells NBC News. He adds "we don't know if it is going to be a significant cause of human hepatitis," but scientists say it's unlikely. In fact, "it may be good for you." They first found the virus in blood samples from two volunteers, part of a study of 46, who received blood transfusions to treat hemophilia between 1974 and 1980. The virus only appeared after transfusions, but both patients cleared it and showed no sign of disease. Two more cases were found among 106 who'd received plasma, per mBio; both cleared the virus, though one was infected for five years. Even if the virus is harmful, researchers say there's no need to panic. "This is not SARS. This is not MERS. This is not HIV," says an expert. Whereas blood transfusions were once performed solely with human blood products, they now use genetically engineered products. Plus, blood is screened more carefully and stricter policies better control who donates blood compared to 25 years ago. "Does it cause trouble that would justify any response with blood safety? I don’t think we're at that level," a pathologist at the Blood Systems Research Institute tells Science. Scientists have yet to isolate the virus but say the next step is to develop an antibody test to find HHpgV-1 in a larger population. Afterward, experts can determine whether those with HHpgV-1 antibodies appear less healthy than those without the virus and look for links to disease. (A study suggests the seeds of Alzheimer's may pass through blood.)