In November 2012, Minnesota Department of Health (MDH) investigated an outbreak of Pontiac Fever associated with a residential hot tub. Four of five individuals met the case definition. All four cases reported fever and muscle aches. One case visited a medical provider. No one was hospitalized. The four people became ill after attending a hot tub party at a relative's home on November 10 in Brooklyn Park, Minnesota.

The owner of the hot tub reported that the hot tub was an eight person residential model unit housed in an outside enclosure in a private backyard. The hot tub had been drained and cleaned in October and was last used approximately 2 weeks prior to the November 10 party. The owner reported that he added chlorine or oxidizing shock after using the hot tub. However, he did not routinely check chemicals and did not check the chemicals prior to use on November 10. The improper maintenance and lack of disinfection of the hot tub likely led to the proliferation of bacteria.