The Department of Health has now received a total of 42 reports of illness and are investigating into each case.
A popular Haleiwa restaurant voluntarily closed its doors for nearly a day after 35 apparent cases of norovirus surfaced earlier this week. State health officials were first alerted of the outbreak on Tuesday after eight participants in Sunday's Haleiwa Metric Century Ride reported symptoms of nausea, vomiting, diarrhea and abdominal cramps but no fever.
"As far we know the common thing among all the people that got sick was that they ate at a certain restaurant," said Chad Taniguchi, Executive Director of the Hawaii Bicycling League.
After further investigation, health inspectors found they all ate at Cholo's Homestyle Mexican Restaurant.
"As of today Thursday, we're up to 35 case reports and most of them are actually not related to the sporting event and just about all of them are related to a common eating establishment in Haleiwa," said state epidemiologist, Dr. Sarah Park.
Several employees and other customers also reported similar symptoms. Lab tests confirm it is the norovirus.
"As soon as they heard they might be associated with a food-borne outbreak they volunteered to close down and clean up I mean even before our sanitation folks were starting their investigation," said Park. "We're also keeping our minds open to the fact that there may be other establishments involved."
Park says the virus is known to surface on cruises.
"If anyone has been on a cruise ship or heard about cruise ship food borne outbreaks, this is the virus that's normally associated with that and in fact, Norovirus is commonly the culprit behind what people like to call stomach flu," said Park.
She says the food-borne illness stems from fecal oral contamination.
"It's exactly what it sounds like, someone pooped and didn't clean their hands very well," said Park. "In a norovirus outbreak it commonly isn't a food source it's commonly a person."
Cholo's voluntarily closed Tuesday afternoon and re-opened Wednesday at noon.
"As far as Cholo's is concerned they did an incredible remediation, cleaning remediation effort overseen by our sanitation experts so I'm pretty confident they're fine now," said Park.
"If it is determined that it was the restaurant I think people should realize that this kind of virus can be spread by anyone at any time that it's not necessarily a reflection on the restaurant's practices or their cleanliness," said Taniguchi.
State health officials say if you have similar symptoms and at an any restaurant in Haleiwa this weekend, see your physician.