Scientists in China have linked latent mortality nodavirus (CMNV) to cases of a condition called persistent ocular hypertension viral anterior uveitis, or POH-VAU. They found evidence of the virus in the eye tissues of people with POH-VAU, many of whom reported recent exposure to raw seafood or marine animals; They also found that CMNV can cause similar eye symptoms in infected mice. If confirmed, CMNV would appear to be the first virus of aquatic life linked to eye disease in people – which could become a growing health concern, researchers warn.
“This study shows that an aquatic animal virus is linked to an emerging human disease,” they wrote in the paper published late last month in the journal Nature Microbiology.
sea blindness
POH-VAU is an emerging eye disease characterized by high intraocular pressure and inflammation of the uvea, the middle layer of the eye. Chronic or recurrent cases of viral anterior uveitis (anterior refers to the most front part of the uvea) are usually caused by certain herpesviruses, including herpes simplex virus (which causes herpes). But study researchers are documenting an increase in POH-VAU cases in China that are not linked to any of these common culprits.
Earlier research had shown that some people with POH-VAU had viral particles in their eyes that resembled those of CMNV, a recently discovered virus that has become a serious threat to shrimp farming operations in Asia and Australia. So the researchers wanted to study whether CMNV could actually cause POH-VAU.
They looked at 70 patients suffering from POH-VAU between January 2022 and April 2025; They also compared these patients with healthy people. As before, the researchers found viral particles similar in size and shape to CMNV in eye tissue removed from patients as part of surgical treatment (and none in the control group). They also found that all patients tested positive for antibodies to CMNV, while genetic testing showed that the virus isolated from people matched 98.96% to CMNV samples found in aquatic animals. Finally, when they infected mice with CMNV, the animals developed symptoms similar to those seen in humans with POH-VAU.
How concerned should we be?
Obviously, more research will be needed to confirm the role of CMNV in causing POH-VAU and to answer other related questions, such as its actual potential to cause human disease. But there is certainly reason to be concerned about the implications of this finding if it is further validated.
For starters, it will shed light on how emerging zoonotic diseases – which can spread from animals to humans – originate not only on land, but also in the ocean. Second, while the majority of cases (about 71%) were associated with direct contact with raw shrimp or other seafood, researchers identified some cases without such apparent exposure. This raises the possibility that CMNV and POH-VAU can spread between humans, although this has not been confirmed.
Even if the disease is spread only through seafood, the risk may increase. The researchers also looked at data showing that CMNV has so far been found in 49 aquatic species that live in waters around the world, including the Americas and Europe.
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