But spokesman Dave Tonelli said Clark County Health District officials see some good news in a decrease in the number of illnesses for last week, down to 74 cases for the week of March 5-12. "Though the cumulative numbers have risen, a slight decline in the number of complaints of new illness occurring March 5 through March 12 was observed over the preceding one-week period," Tonelli said.

"The decline in new cases is encouraging," Tonelli said. "We're cautiously optimistic."

Officials have blamed the outbreak of gastroenteritis on a Norwalk virus or noro-virus that is associated with spending time at the California Hotel and Casino in downtown Las Vegas.

Owner Boyd Gaming Co. ramped up cleaning procedures in recent weeks: including hourly bathroom cleaning, use of hospital-grade disinfectant and handing out alcohol-based wipes in the casino, but cases are still being reported.

The illness — which usually shows up as fever, nausea, vomiting and diarrhea — has inconvenienced many and ruined vacation getaways. But because it's a virus, health officials said there are no treatments or medications to cure it.

Officials recommend drinking water, getting a lot of rest and eating right, not normally habits associated with one of Hawai'i’s favorite vacation destinations, specializing in around-the-clock gambling and eating.

Tonelli said he's hopeful that the extra cleaning is paying off. "It's keeping that heightened level of sanitation."

He also attributed the big leap in the number of cases to media coverage of the outbreak, particularly in Hawai'i, which prompted additional hotel/casino customers to report illnesses that had been previously unreported during December, January and February.

Tonelli said most of the new cases come from the earlier weeks of the outbreak.

However, Tonelli urged visitors to remain vigilant against the unpleasant illness. "It is not uncommon in norovirus outbreaks for a decline to be followed by a resurgence," he said.

Clark County Health District epidemiology officials said that means they won't say this outbreak associated with the California Hotel Casino is over until they see a sustained decline over a one-month period.

The health district reminds guests of any hotel to promptly report incidents of illness to the hotel housekeeping or general staff. Areas affected by vomiting and/or diarrhea must be properly cleaned and disinfected to protect others from getting ill.