The seasonal flu is now widespread throughout Minnesota, state health officials said Thursday, with the number of cases rising sharply for the second consecutive week.

The outbreak is outpacing last year's, with 172 people hospitalized last week because of flu infection — something that didn't happen last flu season until late January.

About 3.4 percent of all visits to medical clinics last week were from flu-like illnesses, a jump from 2.6 percent the previous week.

Even these numbers do not include the full effects of Christmas travel and family gatherings, which tend to accelerate the spread of flu viruses because large groups are confined in close spaces. Next week's flu report from the Minnesota Health Department is expected to reflect even higher numbers.

Flu symptoms include fever, body aches, chills, fatigue, cough and a sore throat. The illness typically passes within a few days, but can cause serious complications, especially in the elderly, young children and people with underlying respiratory difficulties.

The dominant flu strain making the rounds now has caused higher hospitalization rates in the past for the elderly and young children, according to the U.S. Centers for Disease Control and Prevention in Atlanta.

Federal health officials this week recommended that all hospitalized, severely ill and high-risk patients infected with the flu should be treated with antiviral medications.

"It is important to get seen early because there is a chance that they can provide these antiviral treatments to limit the spread and severity of disease," said Joe Kurland, a vaccine specialist and infection preventionist at Children's Hospitals and Clinics of Minnesota.

The best way to prevent the flu is to get vaccinated, said Kurland. Although the vaccine is not 100 percent effective, it reduces the risk of getting infected and can help minimize the symptoms in those who do get the flu. Early treatment with antivirals is also important to keep the flu in check.

But some people do get so sick that they require hospital care and sometimes even a stay in the intensive care unit.

Kurland said about half of those needing ICU care have an underlying medical condition like asthma or diabetes.

"But the other half are hockey-playing, basketball-playing kids but for some reason they end up in the ICU as well, and the vast majority of them are not vaccinated."

Children's has put winter-visiting infection guidelines in place, asking those with symptoms to wear facemasks, restricting visitors who are ill or under age 5, as well as providing different waiting rooms for those who are ill and those who are not.

Patients, visitors and staff are also encouraged to use hand sanitizer and avoid touching the mouth, nose or eyes with their hands, something Kurland recommends to limit spread within households.

Flu can be transmitted stealthily because people infected with the flu can pass it on to others 24 hours before they themselves develop symptoms. In addition to airborne transmission, the virus can live on surfaces for up to 72 hours.

Cleaning "high-touch" areas at home, such as faucet handles or toilet flush handles, can also reduce transmission within a family, Kurland said.