A virus typically found in marine animals has infected humans in China for the first time, leading to serious eye conditions resembling glaucoma. Researchers identified covert mortality nodavirus in all 70 patients studied from 2022 to 2025. The pathogen, linked to handling or eating raw seafood, shows signs of possible family transmission.
Cases of persistent ocular hypertension viral anterior uveitis (POH-VAU), which involves eye inflammation and high pressure damaging the optic nerve, have risen in China without a known cause until now. A team including scientists from the Chinese Academy of Fishery Sciences in Qingdao tested 70 diagnosed patients between January 2022 and April 2025. All tested positive for covert mortality nodavirus, a pathogen that infects marine species like prawns, crabs and fish. Patients received medication to reduce swelling, but about one-third needed surgery and one suffered irreversible vision loss. More than half the patients were home-based handlers of aquatic animals, while 16 percent had consumed raw seafood or been in close contact with high-risk individuals. Epidemiological analysis revealed urban patients lacking direct exposure but connected through family members who handled infected animals, hinting at household spread via shared items. Researchers infected mice, observing eye damage and transmission through shared water. Analysis of 523 aquatic animals worldwide found the virus in 49 species across continents. Edward Holmes at the University of Sydney called the virus's host range remarkable, spanning invertebrates, fish and mammals. He noted no clear evidence of sustained human-to-human spread, describing it as not an epidemic, though the spillover raises biosecurity concerns.
