All four major professional leagues in the United States -- including Major League Baseball, the NBA and NHL, which all have teams in season -- say they are monitoring the flu epidemic, which has caused schools to close in a number of states.
Officials from MLB, the NBA and NHL said they are relying on the advice of the Centers for Disease Control and the World Health Organization, but are not intending to cancel games. Every baseball team is in action this weekend; the NBA has five playoff games scheduled from Friday to Sunday, and there are six NHL playoff games (including one in Canada).
As of Thursday, the H1N1 strain, originally known as the swine flu, had caused at least 109 laboratory-confirmed cases in the United States and the death of a young Mexican boy who became sick while visiting Brownsville, Texas.
Nearly 300 high schools across the nation have been closed because of swine flu fears, and that number is expected to grow. Alabama has postponed high school games and meets until at least next week; Texas has postponed high school events until at least May 11.
The mayor of Bogota, Colombia, denied admission to a pair of Mexican teams playing Copa Libertadores matches in Colombia. And 176 Mexican League matches are being played in empty stadiums.
The Mexican League has canceled its soccer games this weekend and postponed several others. They hope to resume play by May 6, with eight double-headers scheduled.
Meanwhile, Pittsburgh Marathon officials say they're taking precautions and monitoring for the swine flu even though there haven't been any confirmed cases in Pennsylvania.
About 10,500 runners are registered for Sunday's marathon, half marathon and marathon relay. Thousands of people will watch.
Ron Roth, the marathon's medical director, says medical staff will take the same infection-control precautions as in hospitals.
Information from The Associated Press is included in this report