A 21-year-old Salt Lake County man who reportedly had several chronic health problems died Wednesday morning at University Hospital after contracting swine flu, county and state public-health authorities confirmed.

Utah's first death associated with what officials are regarding as a novel and possibly highly dangerous strain of the seasonal H1N1 influenza virus fits the illness pattern forming around confirmed cases reported in several countries. The virus infects children and young adults who have ongoing health problems such as obesity, diabetes and respiratory problems, officials said at an afternoon news conference.

The Utah man, Marcos Sanchez, was ill from other health problems for a few weeks, was hospitalized two days after being diagnosed with the new virus and died about a week later. The specific cause of death will be determined by an autopsy.

Sanchez's mother made the difficult decision early Wednesday morning to let him go. "I knew I had to do it because he was passing away slowly anyways, and I didn't want him to suffer anymore," Christina Huitron told KSL-TV.

Influenza viruses often trigger an increase in low-grade bacterial infections that can quickly become serious or fatal because a person's immune system has been compromised by a new, invading virus, health officials said.

A death was expected, said Dr. David Sundwall, executive director of the state Department of Health. He said that the level of concern among public-health officials here and at the Centers for Disease Control and Prevention remains "alert but not alarmed." He advised Utahns to maintain the same approach, to continue to keep germs from spreading if they have a cold by staying home or coughing away from others and to continue regular hand washing.

The death should not be taken as a cause to run to the doctor's office to be tested, he said. Tests are expensive, and people should seek medical advice first to rule out springtime hay fever or the common cold, he added.

Pre-existing illnesses are forming a definite pattern for public-health authorities, said state epidemiologist Robert Rolfs, noting that 87 percent of the confirmed cases of swine flu have been in people under age 50, and that 70 percent had underlying chronic conditions that could well be aggravating the body's capacity to deal with the infection. Normal flu outbreaks tend to target the very young and the elderly with respiratory problems.

Sundwall, in testimony before the Legislature's Health and Human Services Interim Committee, advised lawmakers and their constituents to avoid "flu fatigue" that seems to be growing because the outbreak is receiving what to many is overwhelming, possibly unwarranted attention from the news media.