MOSES LAKE - The Grant County Health District is working with the Washington State Department of Health to investigate cases of stomach illness in several Grant County residents who attended a recent cheerleading competition in Everett.

The health district asks people who attended the event and are currently experiencing vomiting or diarrhea to contact them at 509-754-6060.

The source of the illness remains unknown.

The health district recently investigated similar instances of stomach illnesses among residents of long-term care facilities.

Area physicians have reported an increase in stomach and intestinal illnesses among patients seen at clinics and emergency rooms. January is usually the peak month for stomach-related illnesses, according to the health district.

There is no specific treatment or vaccine for stomach illnesses, but it's important to drink water to replace fluids lost from vomiting and diarrhea. The health district recommends people experiencing vomiting spoon small quantities of liquid and consume them at frequent intervals.

To prevent the spread of stomach illnesses, the health district recommends people wash their hands frequently; wash fruits and vegetables and cook oysters and other shellfish thoroughly before eating them; not prepare food for others during the illness and for three days after they've recovered; and wash clothing or bedding contaminated with vomit or fecal matter with laundry soap at the longest cycle length, then machine-dry them.