Officials reopened the beach at Diamond Point Park in Bemidji on Friday afternoon, after testing found that water quality was within normal levels.
The beach was closed Thursday after three people became ill July 12 and 13 from E. coli. Health officials determined that the common link was that all three had visited the beach sometime from July 8-11, said health department spokesman Doug Schultz.
All three of those who became ill from the E. coli O157:H7 were hospitalized, and one person developed a complication called hemolytic uremic syndrome, which can affect the kidneys and can be fatal. No additional information about those who became ill was available, Schultz said.
The illnesses likely resulted when the three people ingested lake water containing fecal matter.
Schultz said that fresh water, including recent rainfall, likely helped to disperse the bacteria.
"Chances are that what was there was of a limited quantity and was disbursed," he said. "So it wasn't a surprised that testing found that water quality was within normal levels."
Like many public beaches in Minnesota, the beach at Diamond Point Park was not being tested on a routine basis for bacteria before the outbreak.
While many beaches have been closed in Minnesota as a precaution because of tests showing high bacteria counts, the last E. coli outbreak at a beach happened in 2005. A norovirus outbreak prompted a closing in 2008.