How common are brain-eating amoebas in Lowcountry waterways? Here’s what to know
Taking a dip in the pool, jumping into the ocean or simply having a relaxing day at the lake are frequent activities during the summertime in the South.
But the recent case concerning a patient at the Prisma Health Children’s Hospital in the Midlands contracting a rare, but deadly, brain-eating amoeba, likely while swimming at Lake Murray, has raised concerns about safety in South Carolina’s waters.
From marshes, to lakes, to rivers and even the ocean, how common is this threat in Lowcountry waterways and how concerned should residents and visitors be?
Here’s what to know about the presence of brain-eating amoebas across the Lowcountry’s various waterways and what swimmers should know before taking a dip.
What is this infection?
The organism in question is Naegleria fowleri, often referred to as a “brain-eating amoeba.”
It thrives in warm freshwater environments like lakes, rivers and hot springs. When water contaminated with the amoeba enters the body through the nose – usually during swimming or diving – it can travel to the brain and cause a disease known as primary amebic meningoencephalitis, otherwise known as PAM.
Between 1962 and 2024, only 167 cases have been reported in the entire United States, according to the Centers for Disease Control and Prevention. Of those, just four people have survived, since this infection is almost always fatal.
South Carolina’s history with amoebas
The most recent amoeba case in South Carolina occurred this July when a patient died after likely contracting the amoeba while swimming in Lake Murray.
Previous cases stretch back almost a decade, when in 2016, 11-year-old Hannah Collins of Beaufort passed away after a swim in the Edisto River. Another case occurred in 2012, when 8-year-old Blake Driggers of Sumter also died from the infection after jumping into Lake Marion.
Does saltwater make a difference?
This amoeba is almost exclusively found in warm freshwater sources, such as lakes, rivers and poorly maintained pools. It cannot survive in saltwater, according to the CDC.
The amoeba only thrives in warm freshwater, especially stagnant or slow-moving bodies such as lakes or ponds. That makes ocean beaches and saltwater inlets far less risky when it comes to this rare infection.
While there are freshwater rivers nearby, like the Edisto and Savannah, most of the region’s waterways are saltwater or brackish (a mix of salt and fresh).
This includes estuaries, tidal creeks, marshes, and of course, the ocean. Any body of water with higher salinity levels inactivates the amoeba or causes it to encyst and become dormant.
Studies by the National Institutes of Health and experts from the Mayo Clinic state that there is a possibility these amoebas can thrive in brackish waters, but the risk is much lower, as it is not their preferred environment.
This possibility is more likely at inland rivers, especially those not influenced by the tides, as the freshwater within them can be warm enough in summer to support the amoeba.
Should Lowcountry swimmers be concerned?
While the consequences of infection can be tragic, the risk remains extremely low.
Fewer than 10 people a year in the United States get infected, according to the CDC.
Even with a low risk, the CDC recommends that it is safest to assume you can get a Naegleria fowleri infection anytime you go into a lake or other fresh water.
For a full list of ways to reduce your risk while swimming, click here.
This story was originally published July 25, 2025 at 8:15 AM.
