LAS VEGAS » Health officials say a stomach bug is going around in the Las Vegas area, and they’ve identified norovirus as the cause.

Southern Nevada Health District officials report Wednesday that they’ve seen an increase in cases of gastrointestinal illness in the past few weeks.

Tami Bruno of the epidemiology office says an investigation began March 28 when people at a conference at the Planet Hollywood started coming down sick.

But Bruno says the illness has been reported around the valley, including at private parties and in long-term care facilities.

Norovirus is a common virus that brings symptoms including vomiting, diarrhea and cramps. It’s contagious and can’t be treated with antibiotics.

Officials say sick people should stay home from work or school until at least three days after their symptoms have ended.