Concern is mounting that the world may be facing a global pandemic after an outbreak of a new flu virus in Mexico has spread to the United States, Canada, Spain and other countries. Coordinated cooperation among many nations will be needed if the threat is to be confronted and contained, and the U.S. is actively working with others to contain and confront the threat.

Like seasonal flu, the H1N1 in humans can vary in severity from mild to severe. This strain produces symptoms ranging from mild respiratory infections to severe pneumonia. So far, most cases have occurred in young adults.

Several countries have instituted measures to prevent further spreading, including the screening of travelers passing through affected areas, releasing stockpiles of antiviral drugs and international planning meetings.

U.S. officials —- coordinating with the Mexican government and through the leadership of the U.S. Centers for Disease Control and Prevention —- are responding aggressively. Health officials are closely monitoring all known cases, the State Department has recommended against nonessential travel to Mexico, and anti-viral medications have been made available to local health centers on request.

As one of the first locations where cases have been detected, the U.S. is working to help Mexico bolster its medical laboratories to better test patients and identify possible sources of the flu strain. U.S. officials are teamed up with the Pan American Health Organization and the World Health Organization to share findings with other nations of the world.

While more infections will likely be seen in the coming days, the U.S. and international community are working diligently to limit the impact of the disease and prevent it from becoming a widespread health emergency.