LSU Research Bites: Better Vibrio Bacteria Forecasts Strengthen Health Protections for Oyster Lovers Nationwide
December 10, 2025
Cases of Vibrio vulnificus bacterial infection are on the rise, especially in Louisiana and Florida. LSU researchers have now published new forecasting models in the journal Water Research that reveal what is driving surging Vibrio vulnificus infections.
Better forecasting is helping government programs better protect public health.
Vibrios are bacteria that naturally live in salty, coastal waters. However, their numbers increase with warmer temperatures.
Most species of vibrios are harmless, and some are even beneficial because they act as nature’s "clean-up crew,” said study lead Dr. Zhi-Qiang Deng, a professor in the Department of Civil and Environmental Engineering within the LSU College of Engineering. “Unfortunately, a small percentage of these bacteria are also pathogenic and can cause infections in people.”
Harmful vibrios can infect seafood, such as oysters, when present in oyster-harvesting waters. A person who eats a contaminated raw oyster can develop vibriosis, a foodborne illness characterized by diarrhea, vomiting, and chills. Vibrio vulnificus in particular can cause life-threatening illness, including bloodstream infections that lead to sepsis.
“If there are only a few bacteria in the water column, any raw oyster you eat can only contain a few organisms, leading to a low risk of illness,” Deng said. However, the high Vibrio vulnificus levels that occur in warmer months are why you might have heard the advice to “avoid eating raw oysters in months that don’t have an ‘R',” including May, June, July, and August.
But what other environmental conditions lead to higher levels of harmful Vibrio vulnificus in seafood? LSU researchers combined 13 years of data about the concentration of Vibrio vulnificus in oyster-harvesting waters with satellite response-sensing data.
Did you know?
Vibrios grow incredibly fast. They can infect open wounds, which is why you often hear anecdotes where a person accidentally gets a small scratch while fishing or visiting the beach, and seemingly the next day, they are facing limb amputation.
Vibrios need nutrients to grow, and human blood is full of nutrients that vibrios enjoy.
They then leveraged AI to determine what environmental conditions predict higher concentrations of the bacteria in oysters. They found that not only water temperature but also the amount of solar radiation, water level, wind speed, and water salinity affect bacteria numbers.
“Vibrios can’t be removed from our environment. In fact, they belong there,” Deng said. “However, experts need to be able to predict when and where consumers should avoid contaminated oysters to save human lives. Our research makes it possible to do just that.”
This research study is an outcome of the collaborative research project Satellite-Assisted Forecasting Environment for Improving Oyster Safety, or SAFE Oyster, funded by the NASA EPSCoR Program. Zhiqiang Deng and Crystal Johnson lead the SAFE Oyster project with collaborators from the LSU Health Sciences Center in New Orleans, Southern University, and Louisiana Tech.
Read the paper: Modeling and Forecasting Vibrio vulnificus Concentration of Long-Range Dependence on Marine Environmental Conditions.
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