Pathogens thrive in state’s nutrient-rich waters
Knowledge, simple precautions make summer outings safer
By KELLY BOSTIAN
For the CCOF
Like May flowers that follow April showers, bacterial blooms may follow rainy days that break up summer’s hot streaks.
Heavy rain followed by high temperatures in June gave rise to blue-green algae blooms reported at Grand Lake O’ the Cherokees and at Lake Hefner in Oklahoma City, according to state officials. A Tulsa urgent-care clinic also reported a family that visited Skiatook Lake suffered from exposure to bacteria called Plesiomonas shigelloides, which can cause fever and severe diarrhea.
“Bacteria is something that is natural and there is always a potential you can get sick whenever you go into those kinds of bodies of water,” said Kendra Dougherty an epidemiologist and program manager for the Oklahoma Department of Health Communicable Diseases Division.
A wide variety of bacteria, as well as the extremely rare but deadly Naegleria flowleri ameba, can be encountered in natural waters, so caution is urged not just for people who swim but for those who boat or ski and are hit with spray, for people who wade in to go fishing, or those or who simply wade the shallows in their flip-flops. People who swim their dogs at the local lake also need to take note, she said.
People can have fun but they should be aware and take precautions, she said. As an epidemiologist with specific knowledge of all the pathogens and the potential dangers, Dougherty said she still goes into the lake—occasionally.
“I just kind of have to turn off my rational mind when I go in those types of waters,” she said.
Swimmers should do their best to avoid inhaling or ingesting lake water and any who have contact with the water should wash thoroughly with soap and water as soon as possible after they—or their pets—are out of the water, she said.
“One thing a lot of people don’t think about is open wounds on your body, even small ones,” Dougherty said. “Anywhere you don’t have intact skin and you are an area with a foreign organisms you are open to infection.”
That soap-and-water rule and a thorough wipe down with a clean towel is important for pets too, she said. Animals can be exposed in the water and also when licking themselves afterwards.
“Pets are very susceptible to blue-green algae and can get sick really quickly and can die without hours or days of swallowing the toxin,” she said. “If you know your pet was exposed to (blue-green algae) you should seek care immediately so it can be assessed and be watched for toxin impact.”
It’s not always obvious that bacteria in the water is at a hazardous level, and for several days after being at a river or lake, people should keep it in mind and inform a healthcare provider if they experience lasting rashes or hives, runny nose, cough or diarrhea and headaches, she said.
“The bacteria is always there, but at a certain point conditions allow for it to grow to an illness-causing level,” she said.
High temperatures are what make ideal conditions for bacterial blooms in waters nutrient-rich with phosphorus and nitrogen, which includes the vast majority of Oklahoma’s waterways. Rain isn’t a necessary precursor. Shallow, warm waters are nature’s Petri dishes, but rains may bring blooms at times and in places where some might not expect them.
“That’s something we will see often, a blue-green algae bloom that comes after a period of heavy rain and you have temperatures that just suddenly shoot way up,” said Erin Hatfield, communications director with the Oklahoma Department of Environmental Quality.
People often connect phosphorus and nitrogen runoff with agriculture or livestock waste or from concentrations of waterfowl, but urban runoff and use of fertilizer on lawns can be equally problematic, she said.
“We really encourage everyone to be responsible with the amount of fertilizer they put on their lawns because any excess will be washed off with a heavy rain,” she said.
People who see blue-green algae in public waters should report it to the DEQ complaint hotline at 800-522-0206. The agency only tests waters that are used for public drinking supplies, however. They pass on notification for the public to local agencies or the Oklahoma Department of Tourism.
People going to municipal or county lakes might want to contact their local parks department for information before going. The U.S. Army Corps of Engineers regularly tests water quality at its lakeside beaches and will post alerts when necessary, but because water conditions can change quickly the agency still encourages caution at all times, said Tulsa District Corps spokesman Brannen Parrish.
The main source for recreation and information about current blue-green algae blooms across the state is the Oklahoma Department of Tourism’s Lake Conditions website at travelok/state-parks/lake-conditions.
At the website, travelers bound for any of the state’s lakes can choose their destination from a drop-down menu to check current conditions at that location and find local contact information as well.
The department’s message about blue-green algae is simple: “If it’s green on top, stop!”
People should avoid going into any waters that are discolored, where foam or scum is present or where there is an odor, Dougherty said.
Cyanobacteria blooms are called blue-green algae, even though it isn’t algae, because the large blooms form strings and resemble the look of algae. It can have an appearance like someone poured a blue-green paint into the water. The bacteria also can occur in small amounts not visible to the human eye in warm waters, however.
Learn more about blue-green algae and other pathogens in Oklahoma waters
Oklahoma Lake Conditions website: travelok/state-parks/lake-conditions
State Department of Health website: Oklahoma.gov/health/prevention-and-preparedness/acute-disease-service/disease-information/blue-green-algae.html
Department of Environmental Quality website: Deq.ok.gov/state-environmental-laboratory-services/environmental-public-health-information/harmful-algal-blooms/