Proportion of POH-VAU in ophthalmic clinical patients and treatment effect of POH-VAU. Credit: Nature Microbiology (2026). DOI: 10.1038/s41564-026-02266-x
A virus that typically infects marine animals, such as shrimp and fish, has jumped to humans and is causing chronic eye disease in some people, according to a study published in the journal Nature Microbiology. In recent years, the number of people in China with a condition called persistent ocular hypertension viral anterior uveitis (POH-VAU) has been increasing with no clear explanation as to why. Symptoms include extremely elevated eye pressure and inflammation.
Under suspicion
Researchers suspected that covert mortality nodavirus (CMNV) might be the cause since patients with the condition consistently tested negative for common eye viruses such as herpes or shingles. And earlier investigations had identified unknown virus particles in the eye tissue of a few patients that looked similar in shape and size to CMNV.
To investigate further, scientists in China recruited 70 people diagnosed with the condition between January 2022 and April 2025.
The team examined patient tissue removed during eye surgery with electron microscopes and saw similar virus particles about 25 nanometers in size. No CMNV-like particles were found in the control group of healthy volunteers. To confirm the virus’s identity, they used a special gold-labeled antibody that only binds to CMNV. Sequencing its genetic material revealed a 98.96% match to the version found in aquatic animals.
“This study reveals that an aquatic animal virus is associated with an emerging human disease,” wrote the scientists in their paper.
So, how was a virus normally seen in aquatic animals infecting this group?
Risk factors
The researchers interviewed the patients about their lives, and nearly three-quarters were either handling raw seafood without gloves or were eating raw aquatic animals. “Frequent unprotected processing of aquatic animals and consumption of raw aquatic animals were commonly reported exposure events,” added the team.
To confirm that the virus was actually causing the disease rather than merely being present, the team conducted cell culture studies and infected mice with the virus. These rodents developed the characteristic symptoms of the condition seen in human patients, such as elevated intraocular pressure.
Global risk?
This is the first study to show that a virus originating from aquatic animals can be associated with a specific eye disease in humans. And it may not just be a problem in China.
As part of their study, the researchers conducted a global survey to see how far the viruses had spread. CMNV was found in 49 species, including crabs and mollusks, across Asia, Africa, Europe, Antarctica and the Americas.
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Publication details
Shuang Liu et al, An emerging human eye disease is associated with aquatic virus zoonotic infection, Nature Microbiology (2026). DOI: 10.1038/s41564-026-02266-x
Fabian H. Leendertz et al, Aquatic virus transmission to humans, Nature Microbiology (2026). DOI: 10.1038/s41564-026-02306-6
Journal information:
Nature Microbiology
Key medical concepts