The so-called 'flesh-eating bacteria' is not a single organism but a group of microbes causing necrotizing fasciitis. The primary suspects are Vibrio vulnificus, found in warm seawater, and group A Streptococcus pyogenes, which spreads person-to-person.
Vibrio infects through open wounds in contaminated water or via raw shellfish. It is particularly lethal for those with liver disease or compromised immunity, with a 20% fatality rate for severe cases. Streptococcus pyogenes causes streptococcal toxic shock syndrome (STSS), with a 30% fatality rate.
Recent outbreaks show alarming trends. In the United States, Florida reported a record 82 cases and 19 deaths from Vibrio in 2024 following Hurricane Helene. The state saw another 13 cases and 4 deaths by August 2025. The disease is concentrated along the southern coast, with over 2,600 total infections since 1988.
Asia faces a different threat. Japan recorded a record 977 STSS infections in just the first half of 2024, with 77 deaths, a sharp increase from its historical average of 100 to 200 cases per year.
Europe is confronting rising marine infections. A 2018 heat wave tripled Vibrio cases to 445, mostly in Baltic nations. Spain's Galicia region has recorded three major outbreaks since 1999 linked to local shellfish.
Scientists point to climate change as the key driver. Vibrio bacteria thrive in water temperatures between 20°C and 35°C. Rising sea temperatures are expanding their range northward. The European Environment Agency notes European seas are warming faster than the global average.
The European Centre for Disease Prevention and Control now uses satellite data for real-time risk maps. Analysts warn these bacteria are messengers of a sea thrown out of balance by heat and pollution, posing both health and economic threats to coastal tourism.