MDH working with Zumbrota campground to reduce risks as outbreak response continues

The investigation into illnesses caused by Cryptosporidium and Shiga toxin-producing E. coli (STEC) continues, and Minnesota Department of Health (MDH) disease investigators continue working with the Shades of Sherwood Campground owner in Zumbrota to better determine ongoing risks and to take steps to limit those risks.

Following up on information received from the public, MDH has identified at least 72 people who are part of a waterborne illness outbreak associated with the campground.

In an effort to prevent additional illnesses, the owner has taken several steps at the recommendation of health officials:

• The swimming pool was temporarily closed and hyper-chlorinated to kill any existing Cryptosporidium. The pool has since reopened.

• The campground posted signs at the pool warning visitors to not swim for two weeks if they have been ill with diarrhea.

• The campground closed the man-made water pond (referred to as a water park) to swimming. The pond is constructed in such a way that it cannot be effectively treated to remove Cryptosporidium or other pathogens.

MDH announced last week that it had identified Cryptosporidium infection in people who reported staying at the campground and using recreational water features at the site. One ill person also had become infected with STEC. Health officials asked for the public’s help to report additional illnesses. Officials also asked to hear from people who stayed at the campground who didn’t become ill, in order to better assess and reduce any ongoing risk.

As of Thursday, investigators had identified 72 people who had symptoms consistent with cryptosporidiosis or STEC infection: diarrhea or vomiting for at least three days. The first case became ill on July 1 and the most recent case became ill on Aug. 3.

“Clearly there was contamination associated with this site and transmission has been occurring for some time,” said MDH Infectious Disease Division Director Kris Ehresmann. “We cannot say for certain what the original source of contamination may have been, but we have evidence that ill people were swimming in the facility’s various water features while still shedding the pathogens and reintroducing them into the features over time. That is why it is so important for people to not swim anywhere while they have diarrhea or for two weeks after symptoms of infection with cryptosporidiosis or STEC have stopped.”

From 2008 to 2017, there were 51 reported recreational water illness outbreaks in Minnesota, resulting in 667 known illnesses. Half of the outbreaks were caused by the parasite Cryptosporidium,which can be introduced into water by infected people or animals. It is resistant to chlorine and can survive and spread even in a properly maintained pool or splash pad. That is why health officials recommend that people with symptoms of Cryptosporidium infection avoid swimming while ill and for at least two weeks after symptoms have cleared.

More information about waterborne illness and cryptosporidiosis can be found on the MDH website.