An extremely contagious virus characterized by vomiting, diarrhea and nausea has surface again in Helena, with at least five confirmed cases identified in labs, health officials said Thursday.

Also, at least one retirement home has taken steps to protect its residents from a flu-like bug.

Laurel Riek, environmental health specialist with the Lewis and Clark County Health Department, said norovirus — a dreaded little bug passed on through poor hygienic practices — has surfaced again in the community. It packs flu-like symptoms and often leaves its patients sick for hours if not days at a time.

The virus is spread by infected persons who fail to wash their hands properly after using the bathroom. It can also spread through contaminated droplets sprayed during episodes of vomiting or toilet flushing.

“There are two important aspects, one is hand washing, the other is staying home when you’re sick,” said Riek. “One protects you, and the other protects the rest of us.”

Riek said viral droplets can live outside the body on sinks, tables, door handles and light switches, creating additional opportunity for exposure. Washing hands, she said, is the first true defense against getting sick.

“Eighty five percent of people who are exposed to norovirus will become sick,” Riek said. “Norovirus disease is usually not serious, although people may feel very sick.”

Those who become infected generally fall ill 12 to 48 hours after exposure to the virus. The illness can last from 12 hours to five days, Riek said.

Jim Martinez, service coordinator at Eagles Manor, is working to help contain the spread of a flu-like virus — not confirmed to be norovirus — within the retirement home. More than 130 residents live at the center, the oldest being 97 years old.

“We don’t want it to spread, so we’re asking people who are sick to stay in their room,” Martinez said. “We’re cautioning people who come in that there are flu-like germs around.”

To keep the virus from spreading, managers at Eagle’s Manor began giving residents the option of receiving meals in their room. The home has cancelled many group activities until the virus abates.

Not everyone likes it, Martinez said, but most understand.

“We watch them real close and make sure they’re not affected by it,” Martinez said. “When they are affected, we give them meals in their rooms.”

Reporter Martin Kidston: 447-4086 or mkidston@helenair.com