Effective pandemic preparedness.

Since the identification of 2009-H1N1 in the spring, the virus has caused human disease worldwide and has led to the first influenza pandemic in 4 decades. In North America, despite the unexpectedness of being the early center of the emerging epidemic, public health agencies, health care systems, and medical providers were able to make the immediate switch from preparedness to response, even after the severe economic downturn had affected most of these organizations. Many components of the public health and medical response have been implemented well. Much of the success in the United States is due in large part to the extensive preparedness work that had been done before 2009 by public health agencies and health care institutions across the local, state, interstate regional, tribal, and federal levels. The majority of pandemic influenza planning assumed that the novel influenza virus would likely be of avian origin and start spreading among humans in geographic locations distant from North America. These assumptions of course were based on the best information at the time, recognizing that H5N1 had first emerged and caused serious human disease in 1997, and then after reemerging in 2003 caused widespread disease in birds in numerous countries and continued to cause sporadic human disease in Asia. Although the original planning assumptions were not entirely accurate with regards to viral strain and geographic origination, these plans still provided a solid foundation for much of the country’s and international community’s early 2009-H1N1 response.