The influenza virus hit early this year.

The outbreak has patients filling up doctors offices, urgent care centers and emergency rooms.

"Influenza usually knocks you down and out, you feel horrible," said Dr. Terry Burger, director of infection control and prevention at Lehigh Valley Health Network.

It spreads easily and there's no magic pill or meds to make you better--so doctors say you need to be on guard in any crowded location.

And that includes work.

"Most people who are sick with the flu quite frankly are too sick to come to work," said Burger.

Health experts say your number one defense against the flu is getting the flu shot, after that it's all about reducing the spread of the virus.

You do that by making sure your hands are clean throughout the day and make sure your work surface is clean--you can disinfect your things with wipes or sprays.

"Emptying trash cans frequently if they're filled with tissues," said Burger.

Cover your mouth if you're coughing or sneezing.

"And most importantly if you are ill, stay home until you are symptom free, till the fever's gone, hopefully the cough is gone, sore throat, muscle aches, fatigue," she said.

Once you're on the road to recovery it should be safe to go back to the office--but physicians say you still need to be cautious and careful of your co-workers.

"It is transmitted by touching contaminated surfaces and then touching your eyes, your nose, your mouth, so if you keep your hands clean no matter what surface you touch, you can reduce that transmission," said Burger.