Deadly bacteria alert: why beachgoers need to know their iron levels

by Stephen Cobb on July 5, 2019

beach-square-2018Should you be worried about the upsurge in reports of deadly bacteria associated with seawater? For me, the answer is: Yes!

You might think headlines like this are alarmist – ‘Flesh-Eating’ Bacteria: Know the Basic Science Before Going to the Beach – but there is a real health threat here, one that gets worse when ocean waters and seaside temperatures rise. And it is even more of a threat if you have certain medical conditions.

(Note: Please do not let the climate debate distract you at this point – regardless of what you believe about global warming, warm waters harbor bacteria that can be deadly to some people and you need to know if you are one of them.)

Deadly? Really? Yes

Here are the facts: there is a bacterium called Vibrio vulnificus that thrives in warm, brackish, salty waters, and if you ingest Vibrio or it enters your system via a cut or scrape, the results can range from a mild illness for healthy individuals to death for people who have diabetes, liver disease, compromised immune systems, or iron overload, like that produced by hemochromatosis. Here’s how the website of the US Centers for Disease Control and Prevention (CDC) puts it:

“People with a Vibrio vulnificus infection can get seriously ill and need intensive care or limb amputation. About 1 in 7 people with a Vibrio vulnificus wound infection dies.” – CDC.

Here is another statistic to drive home the point: in 2009, “Vibrio vulnificus infections from eating raw Gulf oysters claimed 26 victims, 10 of whom died.” – Center for Science in the Public interest.

The CDC has stated that, in any year, half the people who develop serious symptoms from Vibrio die, and many of those who survive live with the scars from the skin debridement or amputation that may have been necessary to keep them alive. Here’s more from Topar’s textbook of bacteriology: “Vibrio vulnificus is scarcely recognized by many microbiologists, less so by the public. Yet, in this country, the bacterium causes a disease with over a 50 percent mortality rate, and it causes 95 percent of all seafood-related deaths.”

Why the increase in concern? 

All of the above is solid science and established fact, what is new is the extent to which Vibrio is now being encountered. Consider what Topar’s textbook says: “the bacterium thrives in warm seawater” and is “frequently isolated from oysters and other shellfish in warm coastal waters during the summer months.” Clearly, there is a big overlap with many popular vacation destinations like Florida and the Gulf Coast, but today, in 2019, the coastal waters are warm in a lot more places than they used to be.

Note that Topar also says Vibrio can be found in “seawater, sediments, plankton and shellfish (oysters, clams and crabs) on…the Atlantic Coast as far north as Cape Cod, and the entire U.S. West Coast.” Now that some of those areas are setting record high temperatures, Vibrio is likely to be encountered more often, by more people who don’t take precautions, in areas where doctors are not as familiar with its symptoms and aggravating factors as they need to be.

What’s iron go to do with it?

The science is clear: there are certain health conditions that place a person at risk for serious illness or death from Vibrio vulnificus infection, these include: “liver disease, hemochromatosis, diabetes, stomach problems, kidney disease, cancer, immune disorders (including HIV) and long-term steroid use.” That’s according to Topar who notes: “In these individuals, the bacterium enters the blood stream, resulting in septic shock, rapidly followed by death in many cases. Such individuals are strongly advised not to consume raw or inadequately cooked seafood.”

What is particularly problematic here is that many people who have hemochromatosis – a condition in which the body does not handle iron properly, resulting in iron overload – are not aware that they have it. Hemochromatosis is widely under-diagnosed. You are likely to know if you have diabetes, liver or kidney disease, cancer, or an immune disorder like HIV. But you could be walking around with iron overload and not know it. Fortunately, a simple and inexpensive blood test – a ferritin blood test – can tell if you have too much iron in your body, a condition that is often very easy to fix.

For a detailed account of the science involved, check out this UCLA study: “Iron overload disease causes rapid growth of potentially deadly bacteria.” The entire artcile is worth reading, but here is the key point: “People with the common genetic iron overload disease called hereditary hemochromatosis have a deficiency of the iron-regulating hormone hepcidin and thus develop excess iron in their blood and tissue, providing prime growth conditions for Vibrio vulnificus.”

So please, before you head to the seaside to walk the beach and paddle in the ocean, or do some saltwater fishing, or eat some freshly harvested oysters, consider having yourself – and your family members – checked for excess iron. That way you can take extra precautions (covering your feet when walking on the beach, making sure you have waterproof dressings on any open cuts, and so on). And you can take steps to reduce your iron to healthy levels, like giving blood and eating less red meat. Seriously, giving blood reduces iron levels and it is free.*

Frankly, I think annual medical checkups should include a ferritin test. It is a great way to detect underlying conditions, such as hemochromatosis, before they can do serious damage. Certainly, any woman who turns 40 should get a ferritin blood test annually (for reasons explained here). And it would be great if everyone who was headed to the beach this summer were to ask their doctor for a ferritin test. If they ask why, just say Vibrio vulnificus.

Finally, here’s a quote to underline the point about the northward spread of Vibrio: “Before 2017, Cooper University Hospital in Camden, New Jersey, had seen only one case of severe Vibrio infection in eight years, explained Doktor…an assistant professor at Cooper Medical School at Rowan University. Then, in just two years, the hospital saw and treated five patients, one of whom died.” – CNN.


(*If your iron levels are very high your doctor may order a special course of blood giving, called phlebotomies, and in some less-enlightened parts of the world you may be forced to pay for this, which is a whole other blog post.)

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