If you've got aches, fever, chills and respiratory problems, you're in good company.

Utah has widespread influenza activity, including 81 flu-related hospitalizations so far this season — 43 of them in the past week. The number of cases is already above the peak level reached last season. And there's no indication that flu will wind down soon, according to health-care providers and state health officials.

Utah is the only state that shows "widespread" influenza activity on the map updated weekly by the Centers for Disease Control and Prevention. A number of surrounding states have regional and localized flu activity. Flu in the Eastern United States has been relatively mild.

But there's a lag time in reporting and then tabulating data, so numbers are likely an undercount — even more so since most people don't seek medical attention and don't become part of the count unless they are very, very ill. Even then, they may be treated without any tests to confirm presence of influenza virus.

State health officials emphasize there's no evidence of either pandemic flu or avian flu. The seasonal variety is prowling for victims, they say.

Most of Utah's flu activity is concentrated along the Wasatch Front. By Wednesday afternoon, the Salt Lake Valley Health Department expected the number of hospitalizations in Salt Lake County so far this season would reach "at least 60," spokeswoman Pam Davenport said.

Nearly all of those hospitalized belong to high-risk categories, such as being very young, older than age 65, pregnant or having a chronic illness like diabetes or heart disease, said Susan Mottice, state health department epidemiologist.

Between 25 percent and 28 percent of hospitalized cases in Salt Lake County appear to be "drift" cases, meaning that they are a slightly different form of the virus than was contained in the flu vaccine this year, she said.

But no antigen typing has been done locally, Davenport said, so talk of a rogue strain is speculation.

Dr. David N. Sundwall, Utah Department of Health director, said the best protection for those who have not yet been vaccinated against influenza is to do so. Although it won't prevent 100 percent of flu cases, it will reduce severity of symptoms in those who do catch influenza despite the vaccine. It takes about two weeks to offer its full protection; it offers some right away.

So far, 90 percent of the flu cases that the CDC has "typed" are strains covered by the vaccine, according to Mottice.