Seals harbor the closest known relative of the hepatitis A virus.
Researchers discovered the virus, known as phopivirus, lurking in the organs of harbor seals and a harp seal that died of other causes along the New England coast. Phopivirus is closely related to hepatitis A, which in humans can cause nausea, fever, and jaundice. Like hepatitis A, the new virus appears to primarily infect liver cells.
The discovery suggests that hepatitis A, which only affects primates, could have originated in other animals, researchers report August 25 in mBio. It’s not yet clear if seals passed the virus to humans or vice versa, or if some other animal was involved in transmitting these viruses’ ancestors between species.