Three years after swine flu closed Mexico City and caused an international scare, the Mexican government and local media are at odds over the severity of this season's flu virus.

A new strain of the swine flu virus called A(H3N2) may now be spreading through person-to-person contact, the Public Health Agency of Canada says.

After a lull of several months, an influenza virus that is sporadically jumping from pigs to people in the United States has made another appearance.

Closing schools helps to slow the spread of flu during pandemics, a study of infection patterns in Alberta suggests.