Another Hepatitis Virus Is Identified, Study Says
WASHINGTON (AP) _ Researchers have isolated a previously-unknown hepatitis virus, but experts aren’t sure if it poses a health danger or even if it can cause disease symptoms.
In a study to be published Friday in the journal Science, a large team of scientists report that a virus identified as hepatitis G, or HGV, was isolated from the blood of patients with chronic hepatitis.
``We have shown some association of this virus with chronic hepatitis,″ said Patrice Yarbough, director of research at Genelabs Technologies in Redwood City, Calf., where much of the work was done. ``The implication of this finding is still not known.″
Dr. Harvey Alter of the National Institutes of Health, a coauthor of the study, said that although the virus ``is a newly discovered agent, it probably has been around a long time.″
Alter said that sophisticated laboratory techniques capable of detecting the virus are only now becoming available. No antibody test of the type used to identify other hepatitis viruses has been developed for HGV, he said.
The researchers showed that HGV is present in 10 percent to 20 percent of people who have chronic hepatitis that cannot be attributed to other causes. At least 14 other viruses have been linked, directly or indirectly, to hepatitis, an inflammation of the liver. The disease also has been associated with some types of bacteria, fungi and protozoa, and to alcoholism.
Five distinct viruses, called Hepatitis A through E, have been identified as causing acute viral hepatitis. The seriousness of infection varies from virus to virus, and from patient to patient, but many chronic carriers never experience serious disease.
Hepatitis G, said Alter, was found in some patients who also were found to have Hepatitis C.
Alter said is not known if HGV poses a serious public health problem or even if infection by the virus should be worrisome to a patient. He said more studies are needed on this question.
The research showed that HGV can be transmitted through blood transfusions, but Alter said ``the odds of getting a case of this virus are very low.″
Blood donated for transfusion is tested now for a number of diseases, including the AIDS virus and three types of hepatitis virus. Whether there will be a need to add tests for the new HGV is ``a matter of debate,″ said Alter, because many of the carriers of HGV probably are also infected with other hepatitis viruses. Potential donors shown to have antibodies to the other viruses are prevented from donating blood.
Some patients infected with Hepatitis C also were found to have Hepatitis G, said Alter. These patients would have been rejected as blood donors because of their Hepatitis C infection.
In screening 1,400 approved blood donors, he said, the researchers found traces of HGV in less than 2 percent.
Just how much of a problem HGV could pose for blood transfusions is not known, Alter said, but there is a good possibility that the virus poses no threat at all.
``The rate of transfusion-transmitted hepatitis has dropped dramatically in recent years and is approaching zero,″ he said.
Science, which published the study, is the journal of the American Association for the Advancement of Science.