In June 2013 Minnesota Department of Health staff interviewed a case patient diagnosed with Salmonella I 4,[5]12:i:- identified through routine surveillance. The case reported becoming ill after eating watermelon with family members on May 27 and that additional family members had also been ill. Eight family members were interviewed; six cases were identified including the patient laboratory confirmed with Salmonella. One case was hospitalized for 6 days.

Seedless watermelon and peanut M&Ms; were the only foods available at the gathering. Family members also reported drinking milk and tap water. All six cases reported consuming watermelon. A non-ill control did not. A daughter-in-law purchased the watermelon from a grocery store in Forest Lake, Minnesota on May 24. She cut the watermelon at home and brought half to the gathering and gave half to her parents. Both of her parents became ill and were counted as cases.

Investigators concluded this was an outbreak of Salmonella with seedless watermelon as the most likely vehicle of transmission. It could not be determined if the watermelon was contaminated prior to purchase or if contamination occurred during preparation and/or serving.