The tweets about the swine flu outbreak on the popular microblogging site Twitter were spreading faster than the disease Tuesday.
Health officials say common sense must be used when sorting through text messages that range from bad jokes and advice about not eating pork to legitimate medical updates.
"I think it's worth noting that news of the flu is moving faster than the flu is," said Dr. Vivek Goel, president and CEO of the Ontario Agency for Health Protection and Promotion.
Twitter, with its 140-character limit on posts, has been criticized for spreading misinformation and even panic about the outbreak.
"Twitter is like having your own megaphone," said Montreal emergency ward physician Dr. Clifford Albert of Jean Talon Hospital, who urged Twitter followers to use common sense.
"Everybody has to be discriminating in what they will and won't follow."
The number of confirmed cases in Canada had risen to 13 Tuesday, with Ontario and Nova Scotia each reporting four cases, B.C. with three and Alberta two.
It's the first major international health scare of this type since SARS in 2003 and the availability of information on the Internet, with blogs, websites and social media, has increased tremendously, Goel said Tuesday in Toronto.
And Twitter, a social media site that boasts celebrity users such as Oprah, actor Ashton Kutcher and U.S. President Barack Obama, has become part of the news coverage as people search for information.
Tweets about the outbreak range from posts about swine flu being caused by the government to jokes about Kermit the Frog getting it from Miss Piggy.
But news organizations and public health organizations such as the U.S. Centers for Disease Control and Prevention also are using Twitter to post updates.
Researcher Jeannette Sutton studies the use of social media in emergencies and natural disasters and she said it's normal for misinformation and hysteria to sprout on sites like Twitter.
"It's going to give you a pulse on the crowd like nothing we have ever seen," said Sutton of the University of Colorado's Natural Hazards Center.
"It tells you something," she said from Boulder, Colo. "They are seeking out information."
Public officials can use Twitter in this instance to put out relevant, factual information to questions that people are asking, Sutton said.
Twitter was used to spread information during the recent earthquake in Italy, last year's Mumbai terrorist attacks and the wildfires that ravaged Southern California in the fall of 2007.
Albert agreed Twitter can provide useful information about the swine flu outbreak.
"It can serve as a great tool for following a disease pattern and knowing, if people are honest about it, who's suffering symptoms where. It's a great information gathering device."
But Dr. David Williams, Ontario's acting chief medical officer of health, said people should seek out reliable sources of information such as government websites.
"We can't control those other ones that are out there in the chat lines, etcetera," Williams said in Toronto. "And that's what the public have to be leery about - of what reliable sources are not.
"Its a changing situation that's taxing some scientists and people who are speaking from unreliable sources or just out of opinion - it may be of interest, but I wouldn't put your emphasis on that at this time."