A health alert along southern beaches in the U.S. is alarming visitors and residents alike.

The culprit is a dangerous flesh-eating bacteria most commonly found along warm coastal waters where people swim and fish.

Up next, we take a look at this public-health problem, and what steps can be taken to prevent it.

A word of warning.

Some of what you're about to see may be a little uncomfortable to watch.

actually are endemic to low-salinity estuaries like Tampa Bay.

They are autochthonous, so they don't need to come from a human source, or any other type of inclusion.

They are naturally found.

They are halophiles, so they like the salt water.

Dr. Robert Ulrich is a microbiologist who has studied this highly dangerous bacteria.

He warns shellfish can sometimes be tainted with the microbe.

The oysters, being filter feeders, they take particulate matter out of the water column for nutrient sources.

And unfortunately, when they take these particulate nutrients out of the water, they also take out of the water.

And they don't expel it, and it becomes concentrated in their tissues.

When served raw or undercooked, oysters can become very dangerous.

If you're immunocompromised, you're nearly 80% more likely for this organism to enter your bloodstream.

So, that's when it causes the septicemia, septic shock.

Once that happens, the mortality rates are currently up near 50%.

Experts say to never eat raw oysters.

Instead, steam or fry them to kill any associated bacteria.

They can also be acquired through skin punctures or skin wounds, bathing in waters containing these organisms.

This really only has a high incidence of occurring with immunocompromised patients.

Most importantly, patients with damaged livers.

Typically, in healthy individuals, if you ingest a decent amount of it just causes gastroenteritis, which is diarrhea, stomach, abdominal pain.

And unfortunately that's another reason why it's often underreported.

The more virulent strain of contain capsules, which is a polysaccharide or sugar coating around the cell wall.

This makes the organism more resistant to the immune system.

And human blood makes an ideal host for this super bacteria.

This bacterium is endemic to brackish water.

Unfortunately, our bloodstream is saline, as well.

It does have salt in it as well.

And it's somewhat similar environment to where these organisms are found.

So they're quite happy, if they're not being attacked by the immune system, once it gets in your bloodstream, to divide.

When acquired through a wound in the skin, attacks soft tissue.

The problems it causes the most are called cellulitis and necrotizing fasciitis.

Cellulitis is basically just an infection of the lower layers of your skin.

Necrotizing fasciitis is the reason why it's got the moniker flesh-eating bacteria.

'Cause it does necrotize or kill soft tissues.

And once it becomes septic, once it gets into your bloodstream, it can reproduce very, very rapidly, and get into other tissues in other places in your body, and that's when it becomes really, really hard to control, even with antibiotics.

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Richard Corley was a trucker from Winterhaven, Florida.

They called him Pine Tree.

Lot of people don't even know his real name.

He was a true outdoorsman.

That was his life.

When he was off the road from driving, he was either hunting or fishing.

Richard and his brother Brian shared many outdoor adventures together.

In September of 2015, Richard and some friends went to Fort Myers on a fishing trip.

But when he returned home, something was wrong.

Sunday afternoon, my sister called me, and she said he had come home, and he thought he had the flu bug.

He was sick to his stomach.

He had told her about the cut on his leg.

And he had a little spot up above where the cut was, and he thought something had bit him.

Then the next morning, my sister, she had pulled the sheet off to check the spot.

Didn't look good.

Really had festered up.

Black, real big.

So I told her, I said just call an ambulance and have him go to the hospital.

By Monday afternoon, had taken over Richard's body.

From that morning till 1:00, it had spread from below his knee up to his groin, and was going into his stomach.

By early Wednesday morning, Richard was gone.

We made the decision to clean him up, take the tube out of his mouth, get him all cleaned up and let us say our goodbyes to him.

And once they did that, it -- two minutes, he had -- It was over.

He made the 12th person this year in Florida to die of this bacteria.

And, you know, I know there's certain different ways you can catch it or whatever, but, you know, it just seems like there's not a whole lot of information out there.

The Florida Department of Health keeps up with the reported deaths from this flesh-eating bacteria.

is not a hugely common illness, and on average in Florida, we have about 21 cases a year.

Mackenzie Tewell is an epidemiologist in Hillsborough County, Florida.

The people who have the most severe outcomes with including amputation, skin grafts, who develop sepsis or infection of the bloodstream, or even death, are people with underlying health conditions.

The most severe illness we have the interaction with is hepatitis, other liver conditions like cirrhosis, individuals who consume heavy amounts of alcohol.

Heart disease and diabetes are two others that we often see with individuals with severe outcomes with We would suggest, if you have a health condition, are immunocompromised, have something going on in your health, or you have an open wound, that it's probably not the best time to go into brackish waters, to go fishing, to go the beach.

From the perspective of having lost a brother to this deadly bacteria, Brian wants more to be said about

From April to September, in the hotter months, is when this bacteria moves into the water.

People that come down from up north to the salt water, and they're riding WaveRunners or fishing, and I guarantee a lot of people don't know about this.

And that's all it takes is, you know, to have a cut or something and get in the brackish water back there or whatever, where this bacteria's at.

I just think -- you know, just to try to inform people more about it is why, you know, we've been talking about it.

You know, I don't want to see somebody's little kid die from it.