Result0's video: Travel advisory warns of severe respiratory illness in Mexico

Canadians who have recently returned from Mexico should be on alert for flu-like symptoms that could be connected to a severe respiratory illness, federal health officials said Thursday in issuing a travel advisory. The advisory included the same advice given to all travellers regarding getting a flu shot and taking precautions such as covering coughs and staying home when sick, but adds locations in Mexico where cases of a severe respiratory illness have occurred. Public health officials in Ontario have monitored about 10 people who recently returned from Mexico, with the numbers changing by the hour. "We haven't had any that have been directly tied," said Dr. David Williams, Ontario's acting chief medical officer of health. "We will continue to look, any case that has any remote possibility of connection, we want to see if we can connect those dots correctly." Cause of illness unknown A severe respiratory illness appears to have infected 137 people in south and central areas of Mexico, with cases concentrated in Mexico City and three other areas, including 20 deaths, the Public Health Agency of Canada said. "We are not sure where this is in Mexico, but it's not the tourist area," said Dr. Allison McGeer, director of infection control at Mount Sinai Hospital in Toronto. The deaths were mostly men between the ages of 25 and 44, according to an advisory sent out by federal health authorities. Hundreds of people have also reportedly been hospitalized and health-care workers have also been infected. Officials said there are not yet any reports of the illness outside Mexico. The cause of the illness has not been confirmed. Mexican health officials said samples so far have tested positive for influenza A and B. The working hypothesis is that the cases could be a late-season surge in seasonal influenza, said McGeer, noting most of the illnesses in Mexico have not been serious and there has been nothing new in the last five or six days. 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. Testing samples Anyone who has returned from Mexico within the last two weeks and is suffering similar symptoms is asked to contact a physician. "Until somebody tells us we don't have to worry anymore, these are viruses we want to collect," said McGeer. "What we do want to do is identify if there's some new virus, and the way to do that is for people to get a test if they get a respiratory illness, but it's only in the first few days after you've come back." Mexican health authorities said that many of those diagnosed with the illness have had to be put on ventilators. There's no reason for Canadians to change their plans to travel to Mexico, McGeer said. Public health officials in Canada advise travellers to ensure their vaccinations are up to date before flying, to be careful about washing their hands, covering coughs and sneezes and staying home when feeling sick.