Cases of severe eye inflammation linked to consuming raw fish or handling seafood with bare hands are emerging in China. This marks the first time a virus originating from aquatic animals has caused ophthalmic disease in humans, putting the scientific community on high alert.
Aquatic Virus Attacks Human Eyes
According to a study recently published in the international journal Nature Microbiology, the condition has been officially classified as "persistent ocular hypertension-viral anterior uveitis" (POH-VAU).
While the cause was previously unclear, medical researchers found a breakthrough when "covert mortality nodavirus" (CMNV), which inhabits aquatic organisms, was identified as the causative pathogen.
Researchers at the Chinese Academy of Fishery Sciences in Qingdao analyzed epidemiological data from 70 patients diagnosed with POH-VAU between January 2022 and April 2025. The results showed that 71% of all patients had either handled seafood with bare hands or consumed it raw.
Breaking down the infection routes, 54% of cases involved directly handling seafood without protective gloves or safety equipment, while 17% involved consuming raw fish.
POH-VAU causes inflammatory reactions inside the eye and abnormally elevated intraocular pressure. The condition can cause irreversible damage to the optic nerve, presenting clinical features similar to glaucoma.
One-Third of Patients Required Surgery
Researchers successfully detected CMNV directly from eye tissue and fluids of infected patients.
This virus normally inhabits aquatic animals such as whiteleg shrimp. Its presence in human eye tissue is considered unprecedented.
The same virus was also detected in tissue removed from patients who underwent surgery, further confirming the infection.
In terms of treatment outcomes, most patients improved with medication, but approximately one-third required surgical intervention.
One patient permanently lost their vision despite aggressive treatment.
Mouse Experiments Confirm Similar Lesions; Concerns Over Human-to-Human Transmission
Follow-up experiments using animal models yielded results that support these concerns.
Laboratory mice exposed to CMNV developed distinct lesions in major eye tissues including the cornea, iris, and retina within approximately one month.
Notably, signs of viral transmission were detected among mice sharing the same tank environment, lending weight to the possibility of infection through indirect contact.
Whether human-to-human transmission occurs cannot be definitively determined at this time, but it cannot be entirely ruled out either.
Meanwhile, the mechanism by which this virus specifically targets eye tissue remains unidentified.
The research team emphasized that "comprehensive investigations into POH-VAU patients should be conducted worldwide, particularly in countries with significant aquaculture and seafood consumption."