A bacterial infection that was once thought to be uncommon, but with a notably high mortality rate, is on the rise. Experts are pointing to climate change—especially warmer temperatures and rising sea temperatures—as a significant factor, according to reports.
What’s happening?
Vibrio vulnificus, an “opportunistic bacterial pathogen,” thrives in warmer, low-salinity waters, as stated in a journal article from March 2023. The article noted that while infections were “infrequent,” the associated mortality rates remained alarmingly high.
This bacteria causes a disease known as vibriosis and primarily flourishes in coastal environments, especially where freshwater and saltwater meet. Infections can happen in two main ways: through eating raw or undercooked shellfish, or when open wounds come into contact with warm, brackish water.
Traditionally associated with the Gulf Coast, the occurrence of vibriosis has been creeping up the East Coast in recent years. An article from the Delaware Journal of Public Health reported an average of about 100 deaths related to vibriosis annually in the U.S.
Even though summer isn’t officially over, cases of Vibrio vulnificus infections have surged this year. For instance, the Massachusetts Department of Health reported 71 vibriosis cases in 2025, with 30% of those infected requiring hospitalization. Thankfully, there have been no fatalities reported.
Why is an uptick in Vibrio vulnificus concerning?
Eating shellfish and swimming in warm waters are typical summer activities, which raises the risk for infection as the bacteria’s range expands northward along the East Coast.
In a 2023 report from the USDA’s Economic Research Service, experts indicated that cases of vibriosis are likely to increase due to consistently higher temperatures and warming seas. The following year, a study published in The Lancet Planetary Health echoed similar concerns, suggesting we may be on the brink of a significant global rise in Vibrio-related diseases.
Vibrio, often labeled as “flesh-eating,” can lead to necrotizing fasciitis, a severe infection that damages soft tissues and may require amputations for survivors. A 2023 JAMA report found that Vibrio vulnificus had a 33% case fatality rate, making it responsible for over 95% of seafood-related deaths. The CDC highlighted that about 1 in 5 individuals with this infection may die, occasionally just a day or two after becoming ill.
What can be done about it?
The increasing presence of Vibrio vulnificus serves as a crucial reminder about the importance of addressing environmental issues. There are precautions individuals can take to reduce the risk of infection, as reported by local outlets.
Avoiding swimming in warm waters with open wounds is one precaution, alongside steering clear of raw shellfish and ensuring proper food safety to prevent cross-contamination.
