OGDEN — As many as 50 people have fallen ill in a norovirus outbreak in Ogden, health leaders say, and residents are being asked to be especially cautious to use good hygiene to avoid infection.

The outbreak has been traced back to an Aug. 22 gathering of Latter-day Saints celebrating a ward boundary change, said Lori Buttars, spokeswoman for the Weber-Morgan Health Department. The department first learned of the outbreak two days later.

All of the estimated 40 to 50 infected patients live in Ogden and in the 84401 ZIP code covering some of the southern part of the city, according to Buttars.

"We've been interviewing people ... to try to determine if there was a particular food involved," said Brian Bennion, director of the Weber-Morgan Health Department. "There were foods that were bought at the store, and then foods that were prepared at home. We're trying to work through that."

So far, no such foods have been identified, and "we don't believe it's associated with any restaurants," Bennion said.

"The emphasis right now is good hygiene processes, so it doesn't spread any further," he said.

A norovirus infection typically leads to vomiting, diarrhea and stomach pain, while a fever, headache or body aches are also not uncommon, according to the Centers for Disease Control and Prevention.

Most people recover within a few days, but children and the elderly are more prone to severe cases leading to malnutrition and dehydration, the Mayo Clinic says. Norovirus can be spread from person to person or through contaminated surfaces, food or water.

Bennion said in preventing infection, "it's really important that people wash their vegetables and fruits very well."

"We always stress good hand washing and washing your food," he said.

Surfaces thought to be at risk of contamination ought to be cleaned with a mixture of water and bleach, and cleaning should also involve gloves as a protective measure, Buttars said.

"It's really fast-spreading and lingers on surfaces," she said.

Patients who are infected are encouraged to drink a lot of fluids to combat the dehydrating effects of vomiting and diarrhea, Bennion added. Parents of young children who are infected should take extra measures to ensure they stay hydrated because kids often don't think to do that themselves, he said.

Buttars also asked that those ill with the virus stay at home.

As of Friday, nobody affected by the norovirus outbreak had been hospitalized.

"I think we've got a pretty good handle on it," Bennion said. "We're still working through it, but we're hoping that it's contained now."

Contributing: Mary Richards