/stories/2019/07/invisible-threats-in-the-water

Invisible threats in the water

By Janette Neuwahl Tannen

Invisible threats in the water

By Janette Neuwahl Tannen
UM experts share some ways to avoid water-borne illnesses this summer.

When Lynn Fleming fell while walking along Florida’s west coast in Anna Maria Island, a small cut led to a debilitating case of necrotizing fasciitis that took her life in just two weeks. A few weeks earlier, 12-year-old Kylei Parker was more fortunate. The young girl had just wrapped up a vacation with her family in Destin, Florida, but on the drive home to Indiana, she began to experience symptoms of the same perilous condition. Parker survived after several surgeries on her leg, and she is still recovering. And during this time of year, more people are reporting gastrointestinal issues after swimming in public pools. Many of these cases stem from bacteria or parasites that can be found in water.

These situations highlight the danger of water-borne illnesses that experts say often increase during the summer. University of Miami experts explain some of the illnesses and their causes, such as necrotizing fasciitis and the parasite, cryptosporidium, which is often found in public pools. They also share tips to avoid these illnesses.

Helena Solo-Gabriele
Dr. Hector Bolivar

Helena Solo-Gabriele is a professor of civil and environmental engineering, as well as the associate dean for research in UM’s College of Engineering. Solo-Gabriele studies the various types of bacteria found along beaches, in the ocean, and in seagrass, as well as the interaction of human health and the environment. She has worked at UM for more than 20 years and holds a secondary appointment in the department of Ocean Sciences at the Rosenstiel School of Marine and Atmospheric Sciences.

Dr. Hector Bolivar is an assistant professor in the Division of Infectious Diseases at the Miller School of Medicine. He treats patients at Jackson Memorial Hospital and University of Miami Hospital, and has taught at UM since 2004.

What is necrotizing fasciitis, or flesh-eating bacteria, and how common is it?

Bolivar: Necrotizing fasciitis is an infection that comes from the entry of a bacteria called vibrio vulnificus into the soft tissue of the body, typically through a cut or wound. The family of bacteria often called “vibrio” are prone to move in the water, especially in salt water, and we usually see cases of necrotizing fasciitis from May to September when the water is warmer. The infection can progress rapidly to sepsis and send the body into septic shock, which has a high mortality rate. Vibrio can also be ingested from raw shellfish, such as oysters, and in this situation, it may cause a severe gastrointestinal infection, which can lead to sepsis and septic shock.

Is there anything that may be causing us to hear more about this flesh-eating bacteria?

Bolivar: The warm water causes a proliferation of bacteria and it’s also a time when more people are exposed to the ocean simply because more people are on vacation and in the water. Still, we only see about two to three cases a year of this at Jackson Memorial and University of Miami Hospital, so it is rare. The Centers for Disease Control report about 80 cases per year of necrotizing fasciitis throughout the United States.

What is cryptosporidium?

Bolivar: This is a parasite that stays in the water and is very difficult to eradicate because chlorination needs to be extremely high to do so. If this parasite is ingested, it causes diarrhea, especially in immune-suppressed people who are recovering from surgery or a transplant, as well as people undergoing chemotherapy. There are fewer cases of this becoming fatal than necrotizing fasciitis.

Where and how do most of these cases seem to develop?

Solo-Gabriele: Some people have the misconception that going into the ocean will help clean a cut or dry it out, but this is not true because the ocean is not sterilethere are microorganisms that will infect individuals. While I typically study other bacteria than the kind that causes necrotizing fasciitis, what we seem to find is at a lot of beaches, the source of bacteria is along the shoreline. The highest levels of bacteria tend to be right above the high tide line in the sand.  In the water, the highest levels are usually observed in the very shallow ankle-deep water. In chest deep water, the levels of bacteria are lower.

Bolivar: Most of the patients I’ve seen with this condition were injured in ocean water close to the mouth of a river or rivers, like Tampa Bay, because the concentration of salt in the water changes and this facilitates a proliferation of bacteria.  Ninety-five percent of the time it’s an injury on the skin, or an injury that reaches the muscle and allows the infection to grow. It needs a port of entry in the skin, otherwise it’s not that common. I’ve also seen patients with this condition who sustained an injury in open water, for instance while they were fixing their boat, but others who were walking along the beach and cut their foot. Necrotizing fasciitis develops with swelling, redness and pain around the wound, and you often notice purple blisters developing around the wound.

Are there factors that cause certain people to be more susceptible to these illnesses?

Solo-Gabriele: A lot of these infections happen with people who are immuno-suppressed or have an underlying illness, so they are more susceptible to these infections that enter through a wound. That’s why people should be extra careful if they are immune system is suppressed.

Bolivar: People at high risk for developing complications or infections, such as necrotizing fasciitis or crypto are those with minor injuries already, as well as people with liver conditions, or with transplants who need medication to maintain the transplant, which is called immunotherapy.  

How can we avoid getting these water-borne illnesses?

Bolivar: If you get an injury, get out of the water immediately, and clean the wound with soap and water. Infections usually develop in first 24 hours, so if nothing has occurred after a day, typically that’s a good sign. Also, anyone with an open wound should not go into the water. And if you have any sign of pain around a wound after washing it, you should go to the nearest emergency room.

Also, parents who are taking kids into the water should change their diapers frequently and if the child is having diarrhea, don't take them in the water. And try to avoid drinking seawater or pool water.

Solo-Gabriele:  When you are at the beach, shower with fresh water while you are there or after you get home. If you have a cut, don’t go to the beach or don’t go swimming at the beach. A cut provides access directly to tissues, so it is easier for bacteria to impact the skin. Also, be careful when you eat at the beach. Wash your hands before eating and make sure the water or sand does not contact your food. Finally, wear shoes at the beach to avoid getting a cut. One way to check the amount of bacteria at the beach is to visit the Florida Department of Health’s website, where they measure the levels at beaches around Miami-Dade County each week.  In general though, there are more advantages to going to the beach than disadvantages—for recreation, family time, or fresh air. I would not recommend avoiding it, but just practice extra hygiene while at the beach. If you’re really worried, take a first aid kit, wear shoes and avoid conditions where you may cut your skin.

What is the treatment for someone infected with necrotizing fasciitis or cryptosporidium?

Bolivar: The treatment for necrotizing fasciitis is supported care in the intensive care unit of the hospital, along with antibiotic therapy that is given intravenously. Patients may also need surgical debridement, which is the removal of dead, damaged or infected tissue to improve the healing potential of the remaining healthy tissue. Many times, patients must undergo an extensive operation to remove the dead tissue, and sometimes doctors may have to amputate the limb that is affected.

For crypto, the treatment is an oral anti-parasite medication and plenty of fluids.