Nova Scotia's chief medical officer is warning anyone travelling to Mexico to take precautions as a deadly influenza virus hits that country.

Dr. Robert Strang is also advising doctors in the province to watch out for signs of a severe respiratory illness among patients returning from Mexico.

"So, [if] somebody comes back and is hospitalized, they will be identified as a traveller coming back from Mexico, and that hospital will promptly notify public health and infectious disease specialists to make sure the right next steps are taken," Strang said Friday.

Mexican government officials say 20 people are confirmed dead and 1,004 infected by the new strain of swine flu. Officials have cancelled large public events and closed a number of facilities in Mexico City.

Strang said anyone who becomes mildly ill within a week of returning from Mexico should book an appointment to see a doctor. He advised anyone travelling to Mexico to get a flu shot. However, the U.S. Centers for Disease Control and Prevention has said the seasonal influenza vaccine will likely not protect against the current illness since the strain of swine influenza A (H1N1) virus believed to be behind the recent outbreak is substantially different from the human version of the influenza A (H1N1) virus subtype.

People infected with the virus initially suffer flu-like symptoms that include:

• Fever
• Cough
• Sore throat
• Muscle and joint pain
• Shortness of breath

The illness may elevate to a severe respiratory illness within about five days.