On Aug. 10, 2010, the World Health Organization (WHO) announced that the 2009 H1N1 pandemic has effectively ended, and the world has moved into a “post-pandemic” phase characterized by traditional seasonal patterns of influenza.

“The new H1N1 virus has largely run its course,” WHO Director-General Dr. Margaret Chan said in a telephone news conference. “During the pandemic, H1N1 crowded out other influenza viruses to become the dominant circulating virus. This is no longer the case.”

The announcement came following a meeting earlier of the Emergency Committee of the International Health Regulations (IHR), which consists of leading experts on influenza who provide advice to WHO based on the latest epidemiological and virological data.  

During the past 16 months, the 2009 H1N1 pandemic virus reached every WHO region and affected all but a handful of the world’s countries. Officially, the virus has caused approximately 18,500 deaths. That figure, however, is based only on laboratory-confirmed cases. Dr. Keiji Fukuda, WHO’s leading influenza expert, described the number as a “minimum” and said it may take several years to develop more accurate death toll numbers based on traditional methods of estimating influenza deaths.

In the Americas, more than 8,500 laboratory-confirmed deaths due to H1N1 have been reported (as of early August) to PAHO. Outbreaks in Latin America and the Caribbean peaked in April—August 2009 and, in a number of countries, stretched the capacity of national health systems to handle the large number of cases. Among the hardest hit countries were Mexico and the countries of the Southern Cone.