The History of PAHO

A History of American Leadership 

For 124 years, the United States has led the effort to control infectious diseases in the Western Hemisphere.  

  • In the nineteenth century, diseases like yellow fever, cholera, smallpox, and plague swept through the Americas with devastating regularity, crossing borders as freely as merchant ships. A single outbreak originating in Brazil reached the United States in 1878 and killed 20,000-25,000 people across the South, still one of the worst public health disasters in American history.  

    The consequences for trade and infrastructure were just as severe. The French attempt to build a canal across Panama collapsed in 1889 after roughly 20,000 workers died, most from yellow fever and malaria. 

    Unilateral action didn’t work. Quarantines were costly, inconsistently applied, and the diseases spread anyway. The case for a shared hemispheric response was practical, not idealistic - commerce depended on it.  

    In December 1902, President Roosevelt convened representatives of eleven countries at the New Willard Hotel in Washington, D.C. They established the International Sanitary Bureau—the organization that would become PAHO—with the U.S. Surgeon General as its first Director.  

  • The 1902 Bureau gave the hemisphere a shared clearinghouse for disease intelligence, but over the next two decades, it became clear commerce also needed a common set of rules.  

    In 1924, eighteen American republics adopted the Pan American Sanitary Code, formalizing what the Bureau was always designed to do: stop disease from disrupting trade. It established standardized port-entry measures, quarantine requirements, and sanitation protocols across the hemisphere and prohibited the use of health measures as a pretext for trade restrictions, requiring that sanitary requirements be proportionate to the actual epidemiological risk. 

    The Code was administered by the International Sanitary Bureau, which would be renamed the Pan American Health Organization in 1958.  

    The Panama Canal reinforces the stakes further. After the French failure, the United States took over construction in 1904 and appointed Dr. William Gorgas, a U.S. Army physician, as Chief Sanitary Officer. His disease control campaign eliminated yellow fever from the Canal Zone by 1906. The Canal opened in 1914, shortening the sea route between New York and San Francisco by 60 percent and securing U.S. commercial dominance in the hemisphere. The Canal proved the point PAHO was founded on: American interests in the hemisphere depended on controlling infectious diseases. 

     From 1902 to 1959, PAHO was led exclusively by Americans, with three of its Directors serving concurrently as U.S. Surgeon General. 

  • The record speaks for itself. Working with member countries, PAHO has led the elimination of major diseases from the Western Hemisphere:  

    • Smallpox: The Americas achieved elimination status in 1971, a full decade before global certification 

    • Polio: In 1994, the Americas were the first region certified polio-free. The strategy PAHO pioneered—National Immunization Days, simultaneously vaccinating all children under five—became the global template 

    • Rubella: The Americas were the first region to eliminate rubella and congenital rubella syndrome, in 2015 

    • Maternal and neonatal tetanus: The Americas were the first region to eliminate it, in 2017 

    When epidemic emergencies have struck, PAHO has been at the center of the response. When H1N1 influenza emerged in North America in 2009, PAHO coordinated vaccine procurement, surveillance, and risk communication across member states of widely varying capacity.  

    When Zika swept the hemisphere in 2015–2016, PAHO led the epidemiological response and worked to communicate evolving evidence, including the link to microcephaly, in real time.  

    When measles threatened to spread from Venezuela across the Americas in 2018, PAHO vaccinated nearly 9 million children and stopped the outbreak. No bilateral alternative existed.