Doctor, Minnesota agency caution locals about 6 water ailments
FARGO — "Shark Week" airs on the Discovery Channel every July, captivating audiences with terrifying fascination. Viewers sit in awe of the great white and its sister species.
But locals can let out a sigh of relief; they need not fear the sea's apex predators when they dip their toes into nearby waters.
However, other waterborne ailments exist in the surrounding lakes and rivers.
Waterborne diarrheal illnesses
"The most common types of waterborne illnesses are actually diarrheal," says Trisha Robinson, waterborne diseases unit supervisor at the Minnesota Department of Health (MDH). "Cryptosporidium is our No. 1 offender. We most commonly see it associated with treated recreational venues. Those would be things like water parks, swimming pools, splash pads — things that are chlorinated."
According to MDH, 465 cases of cryptosporidiosis were reported in Minnesota in 2016; six of the eight outbreaks were attributed to waterborne transmission. Robinson says chlorine can often give people a false sense of security, but unfortunately, cryptosporidium survives in even a properly-maintained pool.
"If you're sick, please stay out of water," she says. "Make sure you keep the water healthy for everybody else to enjoy, especially if you're sick with diarrhea."
To prevent these illnesses, people should shower before and after swimming and avoid swallowing water.
"Depending on the different diarrheal illness, some of them are treated with medication, some are not," Robinson says. "If people are worried about symptoms they have, we always encourage them to talk to their health care provider."
Also known as "cercarial dermatitis," swimmer's itch is an allergic skin reaction.
"(Cases) can be so common that we don't actually investigate those in Minnesota," Robinson says.
The rash, caused by a parasite that lives in the blood of waterfowl, appears anywhere from a couple of hours to a day after infected persons have been exposed to infested waters.
"You get this rash in areas you've been exposed," says Dr. Timothy Bischof, infectious disease physician at Sanford Health. "If you're in waist deep, it would only be from the waist down."
While swimmer's itch can't necessarily be prevented without avoiding the water completely, it can be treated symptomatically with Benadryl and other topical steroid creams.
Swimmer's ear — called "otitis externa" — is caused by damage to the ear canal through itching or scratching.
"If you scratch the inner portion of your ear or you're using a Q-Tip and you jab it in too far, you can cause an abrasion," Bischof says. "Then when you get moisture in there from swimming a lot, you can get a bacterial infection like staph, strep or one called pseudomonas."
Those infected may notice redness and itching in the ear canal or sense that it feels full, swollen or painful; some may even notice drainage.
For prevention, Bischof recommends drying ears after swimming.
"You wouldn't want to be sticking a Q-Tip in your ear, but just get as much moisture out of your ears as possible with a dry towel," he says.
Though swimmer's ear can go away on its own, some may need to see a physician for the infection as it can easily treated with antibiotic ear drops.
Hot tub folliculitis
Hot tub folliculitis is often caused by improperly chlorinated hot tubs and water.
"It's essentially a bacterial infection of the hair follicles, specifically with a bacteria called pseudomonas," Bischof says.
The infection causes red, round itchy bumps that look like a rash, often developing into pus-filled blisters like acne.
"When you have the swimsuit on, you get a lot more retained moisture there," Bischof says. "So you tend to see the infection more as a bathing suit-type distribution."
Antibiotics may be required but, in most cases, it will clear up on its own; in the meantime, it can be treated symptomatically with anti-itch medication.
Naegleria fowleri is known as a rare, brain-eating amoeba.
"I think it gets a lot of press because it's well over 95 to 97 percent fatal. It's obviously something very, very serious," Bischof says.
Though severe, there have only been two cases reported in Minnesota (2010, 2012), according to MDH. While low numbers are good news, it also means there aren't many cases to learn from, Robinson says.
"You don't get it by drinking (water)," Bischof says. "You get it by activities where you're getting a lot of water up your nose — so if you're swimming, diving, splashing. The parasite travels up the nose and gets into the brain tissue, causing a very severe meningitis-type infection."
With symptoms similar to a bacterial meningitis, the infection can go misdiagnosed.
"People may have a sudden onset of stiff neck, fever and vomiting; their symptoms progress very fast," Robinson says. "With something like that, people need to seek medical attention very quickly."
To prevent naegleria, people should limit the amount of water that goes up their nose while engaging in swimming or watersports; using a nose clip may help.
"Swimming is a really great, healthy, fun activity. We encourage people to swim," Robinson says. "We just encourage people to take precautions while doing it to make sure they keep the water healthy both for themselves and for others to enjoy."
Dangers near the water
Contrary to popular belief, chiggers don't live in the water.
If swimmers get chiggers, "it's probably not from the water itself but from the vegetation on the side of the river or hiking to and from where you're swimming at," Bischof says.
Dubbed "trombiculid mites" by scientists, chiggers technically fall into the arachnids family with spiders and ticks.
"What they do is they jump on you and then attach. In their mouth, they have an enzyme to break down the skin cells. In a microscopic sense, it kind of liquefies the skin cells and that's how they feed," Bischof says. "When you're infested with those, you typically see hives or welts — a blister-type reaction."
To prevent chiggers, hikers and swimmers should avoid brushing up against vegetation. Similar to avoiding Lyme disease, insect repellent or DEET may also help prevent bites.
If you do get bitten, Bischof recommends washing the area with soap and water.
"Most importantly, avoid scratching so you don't cause an infection of these areas," he says.
Over-the-counter medications like hydrocortisone or calamine can help to reduce redness, swelling and itching, but a lot of times, the bites clear up on their own.
“Dangers near the water”
*according to MDH (first reference):
*attributed to waterborne transmission:
*attributed to WebMD:
*according to MDH (second reference):