By: Jessica A. Dennehy
This summer, as Western New York enjoyed temperate weather thanks to its proximity to the Great Lakes, our southeastern neighbors were dealing with the latest swarm of flesh-eating bacteria. The culprit, Vibrio vulnificus, thrives in warm, salty, or brackish water—conditions prevalent along the Gulf and Atlantic coasts from May into October every year. A highly virulent strain of gram-negative bacteria, it’s already responsible for over ten deaths in Florida, Louisiana, and North Carolina’s Outer Banks. Additionally, it has triggered multiple severe illnesses in Mississippi.
Vibrio vulnificus infections commonly manifest in three distinct pathways: gastrointestinal, wound, and, eventually, sepsis (having entered the bloodstream). Gastrointestinal illnesses are traditionally derived from eating raw or undercooked seafood (oysters are the most common culprit). Vibrio vulnificus is the leading cause of seafood-related deaths in the U.S., responsible for over 95% of known fatalities from ingested seafood, with symptoms including vomiting, diarrhea, and pain in the abdomen.
In contrast, if the bacterium enters the body through an open wound exposed to seawater, it will actually start killing body tissue. Disclaimer: although necrosis is commonly associated with flesh-eating bacteria, the bacteria will not physically eat the tissue, only triggering premature tissue death at a rapid rate. Wound infections have a 25% mortality rate, but if left untreated, both infection pathways can lead to bloodstream infections, or sepsis. If the bacterium is able to enter the bloodstream, septic shock and blistering skin lesions can occur; if this scenario is allowed to occur, 50% of those infected will die. Most deaths will occur within 48 hours of symptom onset.
Beyond the pace at which infections spread, a critical detail of Vibrio Vulnificus is that it is a gram-negative form of bacteria. It already contains a protective polysaccharide capsule that shields it from the body’s immune cells, along with toxins that degrade and destroy body tissues, but being gram negative throws in an additional wrench in treatment: possessing an extra outer membrane, it is resistant to certain kinds of antibiotics. Many common antibiotics, particularly older penicillin varieties, are unable to effectively combat gram-negative strains, requiring doctors to use aggressive, highly advanced medications to even begin treating infections. Paired with the short reaction time between symptom onset and fatal sepsis, treating these infections is a race against time.
State health departments have been reporting an increasing rate of infection: Louisiana has seen 17 this year alone—a number significantly above its yearly average. Florida has reported 16 so far, North Carolina 7, and Mississippi 3. With ocean temperatures climbing, experts warn the bacteria’s reach—and the danger—may continue to grow.
So, even though the Great Lakes are not swarming with Vibrio vulnificus, Western New Yorkers should keep in mind these hygiene tips, courtesy of the Louisiana Department of Health. Just for individual hygiene or for the winter migration to warmer weather:
- Avoid salt or brackish water if you have an open wound.
- If a wound gets wet, wash it immediately with soap and clean water.
- Avoid eating raw oysters or undercooked seafood.
- Seek medical care if you develop infection symptoms after being in coastal waters or eating seafood.