"Have enough household items and groceries so that you will be prepared to stay home for a period of time," she added.
Messonnier said that based on a study of 70,000 Chinese patients, about 15 to 20 percent developed a serious illness - most of whom were older adults.
"Starting at age 60, there is an increasing risk of disease, and the risk increases with age," she said.
"The highest risk of serious illness and death is in people older than 80 years."
Underlying conditions like diabetes, heart disease and lung disease compounded this risk even further, she added.
People in these high risk categories should avoid close contact with people who are sick, clean their hands often, avoid touching surfaces in public places, and avoid crowds in poorly ventilated spaces.
Over the weekend, the federal government issued fresh recommendations that travelers - particularly those with health conditions - defer all cruise ship travel worldwide.
They also recommended that at-risk groups avoid all non-essential travel and long plane trips.
Messonnier advised younger and healthier people to prepare plans to look after elderly relatives.
"We recommend you familiarize yourself with your loved one's medication and help them get extra to have on hand," she said.