Vibrio Vulnificus: The infection occurs in unlikely US regions

BPrior to the summer of 2017, doctors at Cooper University Hospital in Camden, New Jersey, had seen only one case of serious illness, sometimes eating flesh. Vibrio vulnificus.

Since then, they have seen five patients infected with the disease and research published on Monday suggests that these cases are related to the warming of the ocean. More cases are probably incoming.

It's explained the newspaper Annals of Internal Medicine that in the United States, V. vulnificus is endemic along the southeastern coast and is occasionally reported in Chesapeake Bay. But the disease has rarely been associated with Delaware Bay and New Jersey coasts, where the water is colder so far.

How do people get Vibrio vulnificus?

People get sick when the bacterium gets into an open wound – probably when a person is swimming in contaminated seawater – or after eating raw or undercooked shellfish. V. vunificus is just one of the diseases caused by Vibrio Bacteria, but it's the most lethal: while most people with a mild case recover in three days, a serious infection can lead to limb amputation. Globally, it is the most lethal foodborne disease with a 50% mortality rate. One of the patients treated in New Jersey died, while the others recovered from diseases such as vomiting, fever and rash.

Madeline King, Ph.D., professor of clinical pharmacy at the Philadelphia University of Science and co-author of the study, tells reverse that she and her colleagues knew that there had to be a reason why they saw V. vulnificus infections in patients exposed to seafood or swimming in Delaware Bay.

The way patients became ill varied, but each disease was related to these factors.

In one case, a 46-year-old man was infected after being crabbed and a 64-year-old man was infected after being cut off his leg on a crab trap in Delaware Bay. Meanwhile, a 60-year-old man went to the crab, ate the crabs and got sick. A 38-year-old man never went to Delaware Bay, but became ill after eating seafood from there. The 64-year-old man was also infected after cleaning crabs with his hands.

Why men are frequently victims of V. vulnificus

Men are most often victims of the disease. James Oliver, Ph.D., tells reverse about 80% of the victims are men over the age of 40. Oliver was not affiliated with this study and was an expert in the study of V. vulnificus.

"This [the frequency of male victims] seems to be due to the fact that this is the main group of people who develop cirrhosis, "says Oliver. "It also seems that estrogen protects women, to some extent, from the toxin V. vulnificus product. "

Alcoholic cirrhosis damages the liver, the store where iron is found. It's interesting for the bacteria: V. vulnificus affects only people with certain underlying diseases, mainly those who raise the level of iron in the blood. Oliver explains that iron is essential for the growth of the bacteria and that "normal" people do not have enough iron in their blood to allow this growth. Without high levels of iron, the bacteria can not survive even if it enters through an injury.

Why is it V. vulnificus Extend to new areas?

But that still leaves the question of what does this bacteria do in Delaware Bay?

King and his colleagues believe that the geographic extension is probably related to the significant increase in sea surface temperatures in many coastal areas of the country. These, they write, are linked to "longer summer seasons and … changes in the amount, distribution and seasonal windows of bacteria".

"V. vulnificus prefer warmer brackish waters, which is why the higher temperature of the sea in our area would affect the presence of this bacterial species, "said King.

Previous studies have established a link between sea surface temperature and the spread of vibrios and, in turn, recent data have shown that the incidence of VibrioAssociated diseases are increasing worldwide. Most of these cases have been reported during heatwaves and, notes the scientist, the frequencies and intensity of heat waves are likely to increase as the climate crisis persists.

Oliver also reports that V. vulnificus emerges in aquatic areas that are generally too cold to survive – icy bodies such as the Baltic Sea and off the Swedish coast. The warming of the oceans also causes the melting of sea ice, which dilutes the salinity of the water. V. vulnificus requires salt, but the salt level in the ocean is too high for it to thrive. However, dilution of the sea with fresh water has reduced salt levels, facilitating the survival and growth of V. vulnificus.

King hopes that this new study will help "support the idea that warmer sea temperature is likely to affect bacterial species" and will also help clinicians of Vibrio was not endemic before, but could lead to increased infections as the temperature warms up.

Oliver, meanwhile, is adamant in his advice, noting that "public information is essential and that the more people learn about it, the less likely they are to develop V. vulnificus infection."