The U.S. Center For Disease Control reports heavy flu activity around the country, with 29 pediatric deaths attributed to what doctors are calling a"severe" flu season.

For workers who begin experiencing flu symptoms, the CDC advises staying home and not contaminating their colleagues.

That seems like sound advice, but way too many employees are reluctant to call in sick, even when down and out with a flu or cold. According to a 2012 study by business retailer Staples, about 80% of workers show up at the office even if they are sick. Additionally, 66% say they go to work even though they have an illness that's contagious.

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That's not all. A report from Bloomberg says that the rate of sick day usage by U.S. employees is approximately 50% less than in 2006. That's likely due to the economic downturn, as workers believe they can't afford to take a sick day, lest they look like they're shirking on the job.

That begs the question for U.S. employees: If you do catch a bad flu and can't go to work, what's the best way to"call in sick" and ensure your work is done while you're recuperating?

Peter Handel, chief executive at Dale Carnegie Training, a New York City-based international business services outfit, offers up a"to do" list:

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Be realistic. An employee should call in sick when their illness is still contagious and their productivity will decline significantly due to their illness."If an employee knows the quality of their work will be negatively affected due to their illness, it is best for all parties involved to call in sick," Handel says.

Cut yourself some slack. Staffers often feel like they're so vital the office can't survive without them. That's a mistake."We encourage employees to take care of themselves when needed in order to ensure they continually perform their best," he says.

Rouse yourself on a"temporary" basis. Client meetings and high-profile calls scheduled far in advance are often legitimate reasons for employees to try to get into the office even if they are feeling under the weather. If it's impossible to reschedule, employees can offer to call in from home to not miss an important meeting.

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Get ahead of the problem. Employees should make the decision to call in sick as early as possible - even the night before if possible, Handel advises.

• First, notify your immediate supervisors and managers via email and phone. This ensures the message is received in a timely fashion.
• Be in contact with the people you work with and communicate your list of urgent to-dos to them."If there is anything that needs immediate attention while you are out, your proactive communication will allow for speedy delegation and completion," Handel says.
• Remember that it is the responsibility of the sick employee to ensure that all daily responsibilities and tasks are completed."It is not the manager's responsibility to delegate tasks, nor is it a colleague's responsibility to figure it out in a sick employee's absence," he adds.

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• Wash your hands regularly and avoid touching things such as elevator buttons, printer buttons, refrigerator handles, telephones and widely used computers.
• Wipe down your desk space with anti-bacterial wipes.
• Get plenty of sleep during the winter months. Being well-rested is a great defense to avoiding getting sick.
• Use hand sanitizer, or if you are really concerned, get a flu shot and make sure you consult your doctor.

Handel says calling in sick the right way lets you take care of business at the office while you're taking care of yourself at home.