What's Vibrio? Cases of deadly, flesh-eating bacteria up significantly in the US due to climate change: Study
About a dozen Vibrio species can cause human illness, known as vibriosis, and the CDC estimates that vibriosis causes 80,000 illnesses each year in America
The cases of deadly, flesh-eating bacteria called Vibrio have increased significantly in some parts of the US and, according to scientists, climate change is the culprit. In particular, rising temperatures and sea levels have led to an explosion of cases in the Carolinas, and it is being found more often in “rivers, creeks and sounds” along the Carolina coast, suggests a new report.
Since 2007, infections from Vibrio, which can cause diarrhea, nausea, vomiting, fever, chills and even death in a matter of days, have tripled in South Carolina and nearly doubled in North Carolina, reveals the analysis by The State.
“It is a very rapidly moving infection. You can get sick within just hours of exposure. If you’re badly infected and particularly if you don’t seek medical care quickly enough, you can certainly be dead in a day or two,” said John Gnann, an infectious disease doctor with the Medical University of South Carolina.
What is Vibrio?
Vibrio bacteria naturally live in certain coastal waters and are present in higher concentrations between May and October when water temperatures are warmer. About a dozen Vibrio species can cause human illness, known as vibriosis, which has been a nationally notifiable disease since 2007 in the US. The most common species causing human illness in the US are Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio alginolyticus.
The US Centers for Disease Control and Prevention (CDC) estimates that vibriosis causes 80,000 illnesses each year in the US and 100 people die from their infection yearly. Since Vibrio bacteria are not easily identified with routine testing, many cases are not reported. About 52,000 of these illnesses are estimated to be the result of eating contaminated food. The most commonly reported species, vibrio parahaemolyticus, is estimated to cause 45,000 illnesses each year among Americans. About 80% of infections occur between May and October.
While most people with a mild case of vibriosis recover after about three days with no lasting effects, people with a Vibrio vulnificus infection can get seriously ill and need intensive care or limb amputation. About 1 in 5 people with this type of infection die, sometimes within a day or two of becoming ill.
Most people become infected by eating raw or undercooked shellfish, particularly oysters. Certain Vibrio species can cause a skin infection when an open wound is exposed to salt water or brackish water. Brackish water is a mixture of fresh and salt water, and is often found where rivers meet the sea.
Anyone can get sick from vibriosis but a person may be more likely to get an infection or severe complications if they have liver disease, cancer, diabetes, HIV or thalassemia, receive immune-suppressing therapy for the treatment of disease, take medicine to decrease stomach acid levels or have had recent stomach surgery.
“People with compromised immune systems, especially those with chronic liver disease, are more likely to get vibriosis. Eating raw seafood, particularly oysters, and exposing open wounds to saltwater or brackish water can increase a person’s chance for getting vibriosis,” advises the CDC.
Treatment is not necessary in mild cases, but doctors suggest that patients should drink plenty of liquids to replace fluids lost through diarrhea. While there is no evidence that antibiotics decrease the severity or duration of illness, they are sometimes used in severe or prolonged illnesses.
What do the findings say?
Vibrio has long been a problem in the Gulf of Mexico but it is becoming a larger issue along the Atlantic coast due to “surging oceans, more frequent storms, saltier rivers, and warmer seas,” according to Geoff Scott, a scientist from the University of South Carolina. The study suggests that in North Carolina, the number of annual confirmed cases from dangerous forms of the bacteria has gone up from 21 to 41 cases since 2007. In South Carolina, the number of annual infections has increased from 8 to 29 cases since 2007. Experts say the numbers are likely much higher, in part because many cases are not diagnosed or reported.
“It has already become a bigger problem in the last 10 or 12 years. This is going to have a substantial increase in health care concerns and health care costs, and compromise the safety of our waters,” warns Scott, who is leading a research center that is analyzing the changing climate’s health effects on people who live in the coastal South.
More frequent storms are creating saltier waters and warmer weather is heating up waters, all of which are creating the perfect breeding ground for vibrio. “When oceans warm and sea levels increase, saltwater can push farther into freshwater rivers, potentially exposing people who’ve never been around vibrio before, scientific research shows,” the analysis explains.
It adds, “At one spot between Myrtle Beach and Georgetown, South Carolina, Vibrio has been documented more than 20 miles up the Waccamaw River from the ocean, possibly because sea level is rising and pushing saltwater inland, according to reports by South Carolina researchers.”
As hurricane seasons become more intense, it also fuels the problem. “Extreme weather makes conditions more suitable for vibrio. Inland flooding from hurricanes can send fresh water cascading down river basins, temporarily cutting the salinity of areas near the beaches and creating brackish conditions ideal for outbreaks of vulnificus,” says the report.