Tag Archives: salinity

Vibrio Vulnificus, Flesh-Eating or Not? St Lucie River/Indian River Lagoon

The Indian River Lagoon (Photo by Jacqui Thurlow-Lippisch, 2013.)
The Central Indian River Lagoon. (Photo by Jacqui Thurlow-Lippisch and Ed Lippisch, 2013.)

Although the Martin County Health Department reports that Vibrio vulnificus, a bacteria found in the waters of the Indian River Lagoon, is not truly a “flesh-eating bacteria,” in rare circumstances it  can cause horrific blisters, limb amputations, and even death.

The naturally occurring  bacteria is not well understood, but a study published in The Journal of Applied and Environmental Microbiology in 2004 regarding a study in Barnegat Bay, New Jersey states:

“V. vulnificus population dynamics are strongly correlated to water temperature and although the general trend is for V. vulnificus abundance to be inversely correlated with salinity, this relationship depends on salinity levels. Irrespective of temperature, high abundances of V. vulnificus are observed at 5 to 10 ppt, which thus appears to be the optimal salinity regime for their survival…”

This “ideal salinity level” is particularly noteworthy as during the rainy summer months salinities in the Indian River Lagoon lessen, due to polluted freshwater run-off and canal discharges. This situation is exacerbated in the southern lagoon if there are releases from Lake Okeechobee, as there were during the “Lost Summer” of 2013.

People are exposed to the bacteria through an open wound or through ingesting raw seafood, especially infected oysters. Cases occur though out the US, but according to the Center for Disease Control, Florida, Texas, and Maryland report the highest number of cases annually.

Contracting an infection from “vibrio” is extremely rare, and in fact, most people exposed to the bacteria may show no signs of infection at all. Others might experience mild effects such as diarrhea, vomiting, and stomach pain. However, for those who have weak immune systems, chronic liver disease, or other serious health problems, the vibrio can strike very quickly and be fatal.

In 2013, Florida Today reported that Florida averages 50 cases, 45 hospitalizations and 16 deaths annually, most from the Gulf Coast region, according to the Florida Department of Health. They also report  that Brevard County, along the IRL, where Melbourne is located, has had 32 cases of Vibrio vulnificus infections since 1993.

Within the past year, two very serious, but non-fatal cases were reported in Melbourne, in Brevard County; and one fatal incident was reported in Ormand Beach, Volusia County, along the Halifax River, which is connected to the northern Indian River Lagoon, north of Ponce Inlet. Ironically, these central and northern IRL areas are the same locations where there have been high dolphin and manatee mortalities as expressed in NOAA’s 2013 “Unusual Mortality Events,” (UME).

As far as the southern lagoon, it was recently reported in Scripps Newspapers that two FAU/Harbor Branch scientists had found Vibrio vulnificus here as well.

This is unsettling, but to be expected, as this bacteria was probably here when I was 5 years old growing up in Stuart, every summer, full of scrapes and cuts swimming around in the warm waters of the lagoon. We must keep our perspective. Thousands of people have contact with Florida’s waters and the Indian River Lagoon and yet few become sick.

Martin County Health Department Director,  Klaretta Peck, stated in a press release to Martin County elected officials this year:”

“I am writing today to share some information with you regarding Vibrio vulnificus. As you may have heard, some news media outlets have taken a sensationalistic approach to this issue, going as far as reporting unconfirmed cases, which can cause unnecessary alarm to the public. There are no recent cases of Vibrio Vulnificus in Martin County and though vibrio can cause blisters and lesions, is it not a “flesh eating bacteria” and should not be referred to as such.”

This is reassuring, nonetheless, at the height of summer,  a Sewall’s Point mother called me, as I am a town commissioner.  She was worried by what she had read in the papers  and asked me if I thought it was alright to take her three-year old twins swimming at the Sandbar.

“Of course, ” I replied, then  I hesitated:

“Do they have any open scratches?…”

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Vibrio vulnificus information: Centers for Disease Control and Prevention: (http://www.cdc.gov/vibrio/vibriov.html)

American Society for Microbiology: AEM Journal: “Effects of Temperature and Salinity on Vibrio vulnificus Population Dynamics as Assessed by Quantitative PCR”
Mark A. Randa, Martin F. Polz, and Eelin Limhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC520858/#!po=85.4167)