Researchers at the CDC say they have identified Tamiflu resistance in 98 percent of influenza "A" cases this flu season.
About 12 percent of cases were resistant last year.
In December, the CDC recommended doctors take into account a patient's flu type before prescribing any treatment, and provided suggestions for medications other than Tamiflu.
They say flu activity is still relatively low this season, and so is the number of patients affected.
Experts say this is a wake up call for new antiviral treatments, and more rapid testing to detect resistance early.
And working the night shift may increase the risk for obesity, high blood pressure and diabetes.
Researchers at Brigham and Women's hospital had 10 adults sleep and eat at varying times of day and night for ten straight days.
They monitored several vital signs, including heart rate, blood pressure, stress hormones and blood sugar levels.
They found when sleeping and eating habits were skewed by 12 hours, for example those who slept during the day and ate at night, their metabolism was altered.
They also found three participants who did not show signs of diabetes before the study had blood sugar levels similar to those of pre-diabetics.
Stress hormones and blood sugar increased, as well as their blood pressure when their quality of sleep went down.