麻豆果冻传媒影音

Welcome to Culture Clinic, MedPage Today's collaboration with Northwell Health to offer a healthcare professional's take on the latest viral medical topics.

On Monday, Olympic training for the swimming portion of triathlon events, to be held in the Seine River, was for the second day in a row. Then, the men's triathlon event, scheduled for Tuesday, was . The cause: bacteria in the water.

Indeed, when the Seine's selection for Olympic events was announced, it reportedly since swimming in the river has been prohibited for a century. However, France took measures to clean up the famed body of water.

Now, after heavy rains returned high levels of bacteria to the Seine and as officials continue to monitor water quality, MedPage Today asked an infectious disease expert to weigh in on the potential hazards that could be lurking there, and what the risks may be to athletes who swim in the river.

"My understanding is that they're finding high concentrations of E. coli in the water," said Bruce Hirsch, MD, of North Shore University Hospital in Manhasset, New York.

Once the concentration is above 900 colony-forming units/100 mL of water, it's considered unhealthy and potentially risky, he explained.

"It's not just E. coli," Hirsch added. "It's also the company that it keeps."

"A major source of E. coli is the lower intestine of people and animals," and it's not alone there, he said. For instance, other germs of concern could include Cryptosporidium and Giardia, as well as Salmonella and Shigella.

As for the potential health risks, gastrointestinal infection, with symptoms including diarrhea, nausea, and abdominal cramping, is common. "It's very easy to swallow small amounts of water when swimming, especially when exerting oneself and swimming for a long time," Hirsch said.

Infections on the surface of the body -- for instance, through a scratch or a wound -- are also possible, he noted, and people may also experience eye, ear, or upper airway irritation.

"Not everyone is going to be sick, but to ask people to participate in a physical contest in which they're being asked to stretch themselves and there's a good chance that a number of these people can get seriously ill, I don't think that's responsible or appropriate," Hirsch said, adding that cancelling or postponing events and monitoring water quality are appropriate and cautious.

Infections from E. coli or from other bacteria and viruses, should they occur, would impact Olympians' health and well-being, as well as their "ability to perform athletically at their best," Hirsch said.

Additionally, some of these types of infections "get around," he said. So, if an athlete becomes infected, they could potentially expose others around them.

Potential incubation periods vary for each infectious agent and for each individual, as well as by how much of an infection an individual is exposed to, he explained. If there is a huge amount of infection in the infectious inoculum, someone may become sicker faster. Regardless, the incubation period would typically be a number of days from exposure.

Overall, Hirsch said it's "reassuring that we understand the conditions around us are changing," due to, for example, warmer weather, which promotes the growth of bacteria in our environment.

He called the situation affecting the Seine dynamic, noting that he wouldn't be surprised if officials are monitoring water quality in the river more than daily. However, it's not only the Seine that has potential safety issues, he added.

Some concerns regarding pathogens in water have been heightened due to climate change; algae blooms come to mind, he said. When algae "overgrows in warm weather, and you see that kind of scum over the surface of the water, that's a problem." These circumstances can lead to skin and airway issues, he explained.

As for the water quality in the Seine, "we need to get this information and to be as clear-eyed and open-minded as possible [in order to] mitigate any potential risk," Hirsch said, noting that it's important to understand that, "immediately after a severe rainstorm, our waterways may be contaminated."

In Paris, "it sounds like that is what is being done," he said.

Comment