One Long Island resident and two people in Connecticut have died this summer from Vibrio vulnificus, a bacteria found in raw shellfish or seawater, officials have confirmed. 

"While rare, the Vibrio bacteria has unfortunately made it to this region and can be extraordinarily dangerous," New York Gov. Kathy Hochul said in a news release Thursday. The death in Long Island is still being investigated to determine if the bacteria was encountered in New York waters, the release added.

In Connecticut, three residents were known to have been infected with the bacteria, the state Department of Public Health said last month. All three victims were between the ages of 60 to 80 and the two deaths occurred in July, the department said.

But these aren't the only cases that made headlines this year. Last month, three North Carolina residents also died from the bacteria, naturally found in warm seawater and brackish water, the Associated Press reported.

About 100 cases of Vibrio are reported in the United States each year, but because people with mild infections aren't tested, the actual number isn't known, according to the Journal of the American Medical Association. About a third of reported cases are fatal.

How to stay safe from Vibrio vulnificus bacteria

In a statement, Hochul advised the public to "stay vigilant and take responsible precautions to keep themselves and their loved ones safe," including:

• Protecting open wounds from seawater and for those with compromised immune systems
• Avoiding raw or undercooked shellfish, which may carry the bacteria

The Centers for Disease Control and Prevention shares additional tips to reduce your risk, including: 

• Washing your hands after handing raw shellfish
• Avoid contaminating cooked shellfish with raw shellfish and its juices
• Washing wounds and cuts thoroughly if they have been exposed to seawater, raw seafood or its juices

"If you develop a skin infection, tell your medical provider if your skin has come into contact with salt water or brackish water, raw seafood, or raw seafood juices," the CDC's website adds.

What are the signs of Vibrio vulnificus infection?

According to the CDC, symptoms may differ depending on type of infection but can include diarrhea, which is often accompanied with cramps, nausea, vomiting and fever.

For bloodstream infections, signs include:

• Fever
• Chills
• Low blood pressure
• Blistering skin lesions

For wound infections, which may spread to the rest of the body, the CDC says signs include: 

• Fever
• Redness
• Pain
• Swelling
• Warmth
• Discoloration
• Discharge or leaking fluids

An infection is diagnosed when Vibrio bacteria is found in the wound, blood, or stool of a person, the CDC says, and is treated with antibiotics.

"Doctors may need to amputate a patient's legs or arms to remove dead or infected tissue," the organization's website notes.

-The Associated Press contributed to this report.