Local health officials think that within a few days they will have identified the bug that sickened attendees at a popular science fiction convention over the weekend.
Dr. Amy Person, public health officer for Benton and Franklin counties, doesn't yet have an estimate of how many of RadCon's more than 2,000 attendees came down with the reported intestinal illness, or just what it is.
But Person and her team have been able to rule out contaminated food or water as a possible cause.
"It is not food poisoning," she told the Herald on Wednesday.
The likely culprit is a viral illness, which lab tests soon should confirm, she said.
Person said the quick onset of symptoms that have included nausea, vomiting and diarrhea, and rapid recovery, plus the way it seems to spread from person to person, are indicators of a virus.
RadCon organizers said reports from con-goers also leads them to believe the illness is viral.
"Based on reports received from my staff, it's likely someone with the illness came to our convention where it spread like wildfire," wrote Sky Bennet, RadCon Guild chairman, in an email to the Herald. "As we all know, when sick people congregate in large social situations or confined spaces, their illnesses tend to spread rather quickly. ... RadCon encourages people who are sick with this type of stomach flu to drink plenty of fluids and get plenty of rest and try to avoid unnecessary contact with people to help prevent this from spreading further."
People with symptoms are encouraged to see their health care provider, but Person said it isn't necessary to call the health district.
The district received about 100 calls, and is sifting through the reports as the investigation continues, she said.
"We now have enough data," Person said.
She also encouraged anyone who thinks they might have come into contact with the virus to make sure to wash their hands to prevent the spread of illness.
At least 20 cases had been reported by Tuesday. Emergency departments at Kennewick General Hospital and Kadlec Regional Medical Center reported multiple cases.
Lourdes Medical Center spokeswoman Melanie Johnston told the Herald on Wednesday that the Pasco hospital has seen as many as six cases that may be linked to the outbreak, but is continuing to investigate possible connections.