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.

The announcement comes after a number of warnings concerning the H3N2 virus by U.S. authorities in recent months.

The virus is a variant of the swine flu virus H3N2.

Though it usually infects pigs, the A(H3N2) virus has infected 12 people in the U.S. since July 2011, according to the U.S. Centre of Disease Control and Prevention. Most cases have been mild respiratory illnesses, though three people with underlying conditions were hospitalized and recovered.

While in earlier cases the virus had spread from pigs to humans, the most recent cases were spread through limited person-to-person contact, according to PHAC. No cases of the virus have been reported in Canada.

PHAC said it is monitoring the situation closely and increasing its surveillance.

It is also urging Canadians to get the flu shot and to practice proper sneezing and coughing etiquette, as well as frequent hand washing to prevent the spread of the virus.