Flesh-eating bacteria cases on the rise?

Flesh-eating bacteria sounds like an epidemic straight out of a horror movie: oblivious beachgoers infected by an aggressive germ with no hope for a cure! As far-fetched as it sounds, this prospective movie pitch is a growing reality for many residents of the East Coast of the United States. While usually confined to tropical waters in the Caribbean and Florida, warming oceans and recent intense storm surges have pushed these strains of dangerous bacteria as far north as Connecticut.

Flesh-eating strains are marine bacteria that have toxins, which can cause necrosis, or cell death, in soft tissue. Most people are infected when the bacteria, found in salt or brackish waters, encounters open wounds, cuts, or even bruises. The infection is extremely aggressive and can take anywhere from a few days to only a few hours to become fatal. 

Interacting with this bacteria can cause a condition known as necrotizing fasciitis, an aggressive type of skin and soft tissue infection. While many strains of bacteria can be considered “flesh-eating,” it is Vibrio vulnificus that is alarming scientists. Once inside a wound, V. vulnificus produces a type of hemolysin called RTX. A hemolysin is a type of toxin that widens the pores in the membrane of a red blood cell, letting unwanted materials into the cell, and eventually leading to lysis, or the rupture of the cellular membrane. In short, RTX rips apart red blood cells. And if that wasn’t enough, an article from The Journal of Infectious Diseases suggests that RTX also aids V. vulnificus by protecting it from phagocytosis, a process in which immune cells attempt to ingest bacteria as a way of fighting infection.

But don’t get too nervous, luckily V. vulnificus infections are still very rare and are far less severe in healthy individuals. Most infections come from ingesting raw oysters infected with the bacterium, and typically do not fare well in the low pH environment in our stomachs. However, The National Library of Medicine still raises red flags for anyone with diabetes, chronic liver disease, and especially those in immunocompromised states.

Although cases are rare, the spike in infections is still alarming. According to the CDC, V. vulnificus cases have increased 78% between 1996 and 2006. This trend holds strong ties to our changing oceans. In 1992, the northmost flesh-eating bacteria infections sat at the top of Florida. By 2018, cases were reported in New Jersey. Now, they have made appearances in Connecticut. The trend of strains moving further and further north is no coincidence! A Scientific American article reports that spikes in flesh-eating bacterial infections are tied to stronger hurricanes and more frequent storms, both of which are being fueled by climate change. This means that the warming climate is making unusual bacteria, such as V. vulnificus, more prevalent.

Northeastern biology professor Constantin Takacs is currently conducting research on another uncommon strain of bacteria being affected by climate change: the bacterium that causes Lyme disease, Borrelia burgdorferi. Rising temperatures have been pushing infected ticks, who thrive in temperate climates, farther and farther north.

“Functional principles [of any organism] will be generalizable,” said Takacs, “but then there are other processes that will happen differently in different settings … that’s why we also have to study a diverse variety of organisms.”

“Climate change is making these more uncommon species of bacteria more and more relevant to our daily lives, yet our lack of knowledge mirages their dangerous potential.”

Climate change is making these more uncommon species of bacteria more and more relevant to our daily lives, yet our lack of knowledge mirages their dangerous potential. This is why investigations into bacteria are so crucial. We simply don’t know how a species will react until we test it. “It’s hard to generalize,” Takacs continues, “it is going to depend on the type of behavior that that agent has inside you.”

In a warming world, we need to be ready for anything that may rear an unexpectedly ugly head.