Credit Florida DOH
#17,655
Last week, in After The Storm Passes, we talked about some of the dangers people will face in the wake of Hurricane Idalia, with a good deal of attention devoted to the dangers of Flood Waters or Standing Waters.
Last year, in Florida: Uptick Of Vibrio Infections Following Hurricane Ian, and previously here, here, and here, we've looked at the dangers posed by an array of naturally occurring bacteria - Vibrio - that can be most commonly be found in the warm coastal waters of the gulf coast states (Alabama, Florida, Louisiana, Texas and Mississippi), between May and October.
While there are at least a dozen strains of Vibrio (including Vibrio cholerae), the two we concern ourselves with most this time of year are Vibrio vulnificus and Vibrio parahaemolyticus. Both are halophilic (`salt loving’), thrive in warm brackish water, and can infect humans via open wounds or through ingestion.
Of the two, Vibrio parahaemolyticus is by far the most common, but is usually a milder infection. It most commonly occurs through the consumption of undercooked shellfish, or the ingestion of contaminated seawater, although skin infections are possible.
Less common, but generally more serious are Vibrio vulnificus infections, which can occur after an open wound is exposed to waters where the organism is growing, or through the ingestion of contaminated seawater or undercooked shellfish.
Those with weakened immune systems are more likely to experience severe illness, and for those who develop sepsis, the mortality rate can approach 50%.
Last year, Florida recorded 74 cases and 17 deaths (about twice as many as normal, due largely to Hurricane Ian) from Vibrio infection. It should be noted that tens of millions of people swim and play in the Gulf and Atlantic coastal waters every year, and only a small handful are affected.
Nevertheless . . .
Rates of Vibrio infection have been rising, and not just in the southern waters of the United States. Between warming coastal waters, and an uptick in severe storms, the risks are rising up and down the Atlantic seaboard.
On Friday the CDC published a HAN (Health Alert Network) Advisory on this growing threat. Due to its length, I've trimmed the clinical guidance, so clinicians will want to read this advisory in its entirety.
I'll have a bit more after the break.
Severe Vibrio vulnificus Infections in the United States Associated with Warming Coastal Waters
Distributed via the CDC Health Alert Network
September 01, 2023,12:30 PM ET
CDCHAN-00497
Summary
The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to:
- Notify healthcare providers, laboratories, and public health departments about recent reports of fatal Vibrio vulnificus (V. vulnificus ) infections, including wound and foodborne infections.
- Urge healthcare professionals to consider V. vulnificus as a possible cause of infected wounds that were exposed to coastal waters, particularly near the Gulf of Mexico or East Coast, and during periods with warmer coastal sea surface temperatures.
- Share important guidance for managing V. vulnificus wound infections.
Background
Vibrio are bacteria that cause an estimated 80,000 illnesses each year in the United States. About a dozen species of Vibrio are pathogenic to humans. V. parahaemolyticus causes the most infections in the United States, accounting for about 40% of reported cases of vibriosis, followed by V. alginolyticus, which accounts for about 20%. Most people with Vibrio infection have diarrhea. Some people might also have stomach cramping, nausea, vomiting, fever, and chills. One species, V. vulnificus, is known to cause life-threatening infections. About 150–200 V. vulnificus infections are reported to CDC each year and about one in five people with this infection die—sometimes within 1–2 days of becoming ill.
Vibrio naturally live in coastal waters, including salt water and brackish water, which is a mixture of salt water and fresh water. Most people get infected with Vibrio by eating raw or undercooked shellfish, particularly oysters. Some people get infected when an open wound is exposed to salt water or brackish water containing Vibrio [1]. People can also get infected if an open wound comes in contact with raw or undercooked seafood. Open wounds include those from a recent surgery, piercing, tattoo, and other cuts or scrapes—including those acquired during aquatic activity. Extreme weather events, such as coastal floods, hurricanes, and storm surges, can force coastal waters into inland areas, putting people that are exposed to these waters—especially evacuees who are older or have underlying health conditions—at increased risk for Vibrio wound infections. This effect was observed in Florida after Hurricane Ian in 2022 [2].
Unlike other Vibrio species, V. vulnificus is primarily transmitted through open-wound contact with salt water or brackish water, but occasionally (in approximately 10% of cases) the bacteria also can infect people if they eat raw or undercooked shellfish. Person-to-person transmission has not been reported. People at higher risk for wound infection include those with underlying health conditions such as liver disease, diabetes, and immunocompromising conditions [3]. V. vulnificus wound infections have a short incubation period and are characterized by necrotizing skin and soft tissue infection, with or without hemorrhagic bullae. Many people with V. vulnificus wound infection require intensive care or surgical tissue removal.
V. vulnificus bacteria thrive in warmer waters—especially during the summer months (May to October) and in low-salt marine environments like estuaries. In the United States, V. vulnificus infections have been most commonly reported by Gulf Coast states. However, V. vulnificus infections in the Eastern United States increased eightfold from 1988–2018, and the northern geographic range of infections has increased 48 km per year [4]. During July–August 2023, the United States has experienced above-average coastal sea surface temperatures and widespread heat waves [5]. During the same period, several East Coast states, including Connecticut, New York, and North Carolina, have reported severe and fatal V. vulnificus infections. Many of these infections were acquired after an open wound was exposed to coastal waters in those states. Some of these infections were associated with consumption of raw or undercooked seafood or had unclear etiology.
Amid increasing water temperatures and extreme weather events (e.g., heat waves, flooding, and severe storms) associated with climate change [6], people who are at increased risk for V. vulnificus infection should exercise caution when engaging in coastal water activities. Prompt treatment is crucial to reduce mortality from severe V. vulnificus infection. CDC continues to monitor reports of V. vulnificus infections.
Recommendations for Healthcare Professionals
This guidance pertains to managing severe V. vulnificus wound infections.(SNIP)
Recommendations for the Public
Taking the following steps can help keep you safe:
- Stay out of salt water and brackish water if you have an open wound or cut. If you get a cut while you are in the water, leave the water immediately.If your open wounds and cuts could come in contact with salt water, brackish water, or raw or undercooked seafood, cover them completely with a waterproof bandage.
- Wash open wounds and cuts thoroughly with soap and clean, running water after they come in contact with salt water, brackish water, or drippings from raw or undercooked seafood.
- Cook raw oysters and other shellfish before eating.
- Always wash your hands with soap and water after handling raw shellfish.
- Seek medical attention right away for infected wounds.
Learn more about how you can help protect yourself from Vibrio.
For More Information
- Last year - for the first time - we saw the CDC issue a HAN Advisory: Melioidosis Locally Endemic in Areas of the Mississippi Gulf Coast on a bacteria which is normally found in tropical regions (primarily Southeast Asia and northern Australia).
- And over the past decade, cases of a rare, mostly fatal brain infection caused by free living amoebas (Naegleria fowleri) - formerly found mostly in southern states like Texas and Florida - have been creeping northward (see map below).
Other health threats - like avian flu, vector borne diseases (e.g. WNV, Dengue & Malaria,), and invasive fungi (e.g. Coccidioidomycosisis & Cryptococcus gattii) - have all made inroads into North America over the past couple of decades, and more can be expected.
This was 6 months before COVID emerged in China, yet a SARS Coronavirus was listed as #6 on their hit parade, while Monkeypox (aka Mpox) - which began spreading globally in early 2022 - was ranked as #29. Melioidosis - which we discussed earlier - was ranked at #32.
Their #1 concern - zoonotic influenza (e.g. H5N1) - has since become endemic in North American birds, and while it hasn't sparked a pandemic (yet), it continues to spill over into mammals as it evolves.
A reminder (as if we needed it) that we live in a dynamic and ever changing world, and new threats can emerge or arrive at any time. Like viruses, bacteria, and fungi . . . we either adjust and adapt to those changes, or we suffer the consequences.
