Waterborne illnesses are far from eradicated, and they’re more than just a case of diarrhea. Americans shell out an estimated $500 million in health care costs to treat the conditions each year, 
according to a new report from the Centers for Disease Control and Prevention.
Legionnaires’ disease: $101 million to $321 million. Characterized by fever, nausea and diarrhea, and achy flulike symptoms, Legionnaires’ disease afflicts around 25,000 Americans each year.
Diagnosis and treatment can quickly add up. Blood tests, chest X-rays and liver-function tests might be required, and antibiotics are the usual solution. But Legionnaire’s can quickly turn fatal: Among patients who develop it in a hospital, death rates are around 50 percent.
Prevention? Treating water systems is the reliable standby, but the disease can also fester in large air conditioning systems.
Cryptosporidiosis: $37 million to $145 million. Also known as “crypto,” this parasite is found in recreational waterways and drinking water across the country, and is spread through the feces of infected people and animals.
Diarrhea is the characteristic symptom, and though crypto usually clears up on its own, those with compromised immune systems risk hospitalization.
Prevention? This one’s up to you. Don’t swallow pool water, wash your hands thoroughly — and if you’ve recently had crypto, do us all a favor and stay out of the hot tub for at least two weeks.
Giardiasis: $16 million to $63 million. You might know it as “beaver fever,” and you’ve probably been afflicted. The CDC estimates that 2 million Americans suffer giardiasis each year.
The illness, characterized by two weeks of cramps and diarrhea, is usually caused by raw sewage that’s leaked into drinking water. It can be transmitted person to person, leading to communitywide outbreaks.
 Around 80 percent of cases are treated with a course of antibiotics, but resistance to common medications is making beaver fever tougher to tackle.
Prevention? If you’re enjoying the great outdoors, don’t rely on untreated surface water.
