How to clean your house to help keep your family safe from the flu The flu epidemic has spread to nearly every state in the U.S.

 -- As the flu season worsens -- Hawaii is now the only state not reporting widespread flu activity -- people are looking within their homes to see what they can do to prevent the flu.

Your home -- a contained space where you spend much of your time -- can be a surprising hotbed of germs.

Making the flu more difficult to contain is how quickly the virus can spread. A new study by researchers at the University of Maryland found that patients breathe the influenza virus out through their noses and mouths in small particles.

“We were able to culture the virus from over 40 percent of the aerosol samples we collected, proving that these fine particle aerosols are infectious and capable of transmitting infection,” one of the researchers, Dr. Donald Milton of the University of Maryland School of Public Health, told ABC News.

If someone in your family is sick with the flu, doctors advise quarantining that family member to prevent the spread of the virus.

If no one in your home is sick, there are steps you can take to try to germ-proof your home as much as possible.

Here are doctors' tips.

1. Become a 'hand-washing czar.'

"The single most important thing you should sanitize are your hands," said Dr. William Schaffner, infectious diseases specialist at Vanderbilt University Medical Center. "When we're out in the world, touching this that and the other, the final common pathway is our hands."

Schaffner said his wife, whom he calls the "hand-washing czar" of his home, has instituted a rule that everyone should follow.

"You enter our house, hang up your coat and immediately go to the sink and wash your hands," he said. "That helps prevent introducing the virus to our home."

2. Forget the rules about sharing.

Dr. Peter Shearer, an emergency medicine physician at New York City's Mount Sinai Hospital, advises people to forget what their parents and teacher taught them about sharing during flu season.

"You sort of hate to, but during flu season, it's probably more hygienic to have people drying their hands on paper towels," Shearer said. "Rather than frequently everyone in the family drying on one [hand] towel."

Likewise, members of the same household should use their own bath towels and washcloths too.

3. Use a humidifier.

Using a humidifier can help slow the spread of those tiny particles of influenza that can suspend in the air.

"We do know that influenza survives less well in warmer, humidified air," Shearer said.

4. Clean hard surfaces first, bedding last.

Keep your cleaning simple by focusing on the hard surfaces you touch the most, according to Dr. Randy Bergen, clinical lead of Kaiser Permanente Northern California’s Flu Vaccine Program.

"The viruses do stay in the air for a period of time, but they also land on surfaces and can stay on surfaces for a period of time," he said. "They can stay conceivably hours after you’ve touched something."

Take stock of your family's daily routines in the house and map your cleaning strategy from there. Think nightstands, countertops, sink faucets, light switches, doorknobs, remote controls, telephones, refrigerator handles, children's toys and even your garage door opener and the number touchpad for your home security system.

"I would be doing it at least daily," Bergen said of wiping down your most highly trafficked areas. "To be safe, do it from November to April [flu season] because it seems like there is always some germ that’s coming through."

Bergen said any cleaning formula that features bleach or an antibacterial product will do the job and you can use a hand towel or paper towel to dispense it.

For bedding and children's stuffed animals, there is less of a need to clean those frequently, according to Bergen.

"I worry a little bit less about those surfaces than the harder surfaces that clearly have been shown to contain the germs for hours," he said. "If someone is sick and has been in bed for a few days and is starting to feel better, then I think it is wise to clean the bedding."

5. Look at your house from kid-level.

Shearer said often-overlooked spaces that should be remembered when wiping down hard surfaces with an antiviral cleaner are the handles of cabinet doors and drawers.

When cleaning handles, make sure to remember the low-to-the-ground drawers that maybe you don't use every day but your child can easily reach.

Likewise, if you have a child who is crawling or playing on the floor, make sure the floors stay clean and you wash your hands after picking up toys from the floor.