Drug-resistant organisms found in the bays and beaches around Olympic host city Rio de Janeiro have Brazilian researchers worried about the health of athletes. But some of these same "superbugs" could be lurking in U.S. waters and beaches, too.
Scientists who are working on the problem believe that these resistant bacteria are created in hospitals , nursed in sewage plants and then eventually dumped into coastal waterways.
While conventional treatment chemicals like chlorine can kill many of these organisms, they often don't kill the most resistant ones, according to Pedro Alvarez , professor of civil and environmental engineering and chemistry at Rice University.
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"It's certainly a concern because these multi-drug resistant bacteria are capable of eventually breaking down our last line of defense," Alvarez said. "It's a very scary situation."
The worst are called carbapenem-resistant Enterobacteriaceae , or CRE -- a family of germs that are resistant to antibiotics considered to be the drugs of last resort.
Healthy people don't generally get CRE infections -- they usually form in more vulnerable people, such as patients on ventilators, urinary catheters or intravenous catheters, or those who are taking long courses of certain antibiotics, according to the Centers for Disease Control .
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But getting such an infection is dangerous. One report says that CRE can contribute to death in up to 50 percent of patients who become infected.
In recent months, Brazilian researchers have found CRE-resistant bugs in Rio's waterways, according to CNN .
The scientists found them at Flamengo and Botafogo beaches, which are near Guanabara Bay, where Olympic sailors will compete next month. The researchers believe that bacteria-laden sewage from local hospitals was funneled into the bay.
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CDC spokeswoman Brittany Behm said that antibiotic-resistant CRE are found naturally in coastal waters, including those in the United States.
"The risk of getting an antibiotic-resistant infection from exposure to sewage-contaminated recreational water is not well studied," Behm said in an e-mail to DNews. "Data from the U.S. show that exposure to healthcare settings is the predominant risk factor for getting antibiotic-resistant infections."
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But last fall, scientists at the U.S. Environmental Protection Agency reported CRE in seven sewage treatment plants across the country, including one in Southern California.
Other researchers have found similar results in sewage treatment plants in Brazil, Portugal, Poland, India and Japan.
Alvarez believes the only way to stop this threat is by developing new treatments, but also changing human behavior. Antibiotics must be more restricted, he said, and perhaps hospital sewage treatment plants need to be tested and become self-contained so they don't discharge drug-resistant organisms into local waterways.
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"We need both technological innovation, better ways to kill and disinfect, making sure that they don't spread through sewage or wastewater treatment plants," he said. "We also need more policy and related non technical solutions. Number one is to avoid the misuse of antibiotics."
Olympic officials say the risk of infection is small, but are warning athletes to shower after leaving the water or shoreline.
EPA spokeswoman Cathy Milbourn says that the agency will continue to track the evolving science on how wastewater treatment affects antibiotic-resistant bacteria.
"Wastewater is typically disinfected prior to discharge," she said. "EPA is not familiar with any conclusive scientific studies that show that antibiotic-resistant bacteria are more resistant to being killed or deactivated by wastewater disinfection processes than non-antibiotic-resistant bacteria."