The number of flu cases in Helena has been gradually ticking up since the first cases of the season were reported in mid-December.

In January, the number of flu cases in Helena averaged five a week, according to the Lewis and Clark City-County Health Department.

During the last flu season, from October 2006 to May 2007, the health department saw 128 cases.

Kay Robertson, a public health nurse with the department, said the exact number of flu cases is hard to determine because the reported cases may be the "tip of the iceberg."

"I think the point is we know it's in the community," she said.

"A lot of common colds that circulate in winter are collectively known as 'the flu,' " said Mike Henderson, the city-county health department's disease control and prevention administrator.

Symptoms of the actual flu virus include high fever, severe muscle aches and extreme exhaustion that can last for two weeks.

Nationwide, about 225,000 are hospitalized with the flu each year, and 36,000 people die from the illness.

Flu is highly contagious, and a cough or sneeze can launch the virus that causes it into the air or onto nearby surfaces.

Keeping hands washed and away from eyes, noses and mouths can be an effective way to avoid the flu, Roberson said.

The flu is often thought of as a wintertime illness, but the peak of the annual flu season can come as late as April or May, she said.

And, unlike some years past, the supply of flu vaccine is plentiful this season, she said.

"Flu is in the community, and you might want to get a flu shot," she said.

Some at-risk groups, such as those over 65 and those with certain chronic health conditions, are targeted for flu immunization. Robertson said the trend is to encourage everyone who can to get a shot.

Also, prescription antiviral medications can reduce the duration of some flu cases when they are administered during the first two days of the onset, and they can sometimes prevent a person from catching the flu after coming into contact with a flu victim.

Flu shots are available from health-care providers, and on Mondays, Wednesdays and Fridays from 11 a.m. to 4 p.m. at the city-county health department, 1930 Ninth Ave.

For more information, there is also a flu hotline, 457-8904.

City editor Richard Myers: 447-4071 or rich.myers@helenair.com