The LPGA Tour is monitoring the situation after seven people, including star and defending champion Rose Zhang, withdrew from the Mizuho Americas Open due to various illnesses this week.
Zhang, 20, pulled out of the New Jersey tournament after just three holes on Thursday.
"I am really disappointed that I had to withdraw from the Mizuho Americas Open today," Zhang said in a statement on social media. "This tournament holds a special place in my heart, having had such an amazing week last year when I captured my first LPGA Tour win here at Liberty National. I was really looking forward to trying to defend my title, but unfortunately spent the last 12 hours with really bad intestinal pain."
Zhang has won twice on the LPGA Tour, including for the first time in her career at last year's Mizuho Americas Open — which she did as an amateur. She won the Cognizant Founders Cup earlier this season, too.
She was far from alone in withdrawing from the event. Maja Stark and Caroline Masson pulled out ahead of the tournament due to illnesses, and they were replaced by So Mi Lee and Mao Saigo as alternates. Lee was sitting in second at the midway point of the tournament, and Saigo was three shots back.
Ruoning Yin withdrew after her opening round, as did Paula Creamer, Lindsey Weaver-Wright, Jiwon Jeon, Haeran Ryu, A Lim Kim and Minami Katsu also withdrew from the tournament. Three of the 10 golfers who withdrew did so due to injuries, unrelated to the apparent sickness that’s going around the course. Specifics of the illness — other than Zhang saying she had “bad intestinal pain” — are not known.
"Medical professionals on site have treated several athletes for symptoms related to a viral infection," the Tour said. "The LPGA and tournament organizers continue to monitor the situation closely, and are working together to advise and assist the LPGA athletes with precautions to try to keep everyone healthy."
Thailand’s Atthaya Thitikul led at the midway point by two shots, though she was quickly overtaken by Hannah Green on Saturday after she posted a 9-under 63. Nelly Korda, who won five straight times on the Tour earlier this year, was just three shots back of the lead as of Saturday afternoon.