During the 19th century, waves of communicable diseases swept Europe, accompanying the growth of railways and steam navigation. Yet the first international sanitary conference, attended by 12 governments, was not held until 1851. An international convention on quarantine was drawn up, but it was ratified by only three states. Progress was slow.
The limited objectives of the nations participating in these early conferences also militated against the success of international health efforts. International public health did not come of age until the 20th century. The first international health bureau with its own secretariat was established by the republics of the Americas in 1902—the International Sanitary Bureau. The name was changed in 1923 to the Pan American Sanitary Bureau.
The idea of a permanent international agency to deal with health questions was seriously discussed for the first time at the 1874 conference, but it was not until 1903 that the establishment of such an agency was recommended. By that time, scientific discoveries concerning cholera, plague, and yellow fever had been generally accepted. The agency, known as the Office International d'Hygiène Publique (OIHP), was created in December 1907 by an agreement signed by 12 states (Belgium, Brazil, Egypt, France, Italy, the Netherlands, Portugal, Russia, Spain, Switzerland, the UK, and the US). The OIHP was located in Paris, and its first staff consisted of nine persons. Originally a predominantly European institution, the OIHP grew to include nearly 60 countries and colonies by 1914.
World War I left in its wake disastrous pandemics. The influenza wave of 1918–19 was estimated to have killed 15 to 20 million people, and in 1919, almost 250,000 cases of typhus were reported in Poland and more than 1.6 million in the USSR. Other disasters also made heavy demands on the OIHP, which found itself overburdened with work.
Early in 1920, a plan for a permanent international health organization was approved by the League of Nations. United official action to combat the typhus epidemic then raging in Poland was urged by the League's Council. The OIHP, however, was unable to participate in an interim combined League-OIHP committee. This was partly because the US, which was not a member of the League, wished to remain in the OIHP but could not if the OIHP were absorbed into a League-connected agency. The OIHP existed for another generation, maintaining a formal relationship with the League of Nations.
The OIHP's main concern continued to be supervision and improvement of international quarantine measures. Smallpox and typhus were added to the quarantinable diseases by the International Sanitary Convention in 1926. Also adopted were measures requiring governments to notify the OIHP immediately of any outbreak of plague, cholera, or yellow fever or of the appearance of smallpox or typhus in epidemic form.
The League of Nations established a permanent epidemiological intelligence service to collect and disseminate data worldwide on the status of epidemic diseases of international significance. The Malaria Commission was founded and adopted a new international approach: to study and advise on control of the disease in regions where it existed rather than to work out the conventional precautions needed to prevent its spread from country to country. The annual reports of the League's Cancer Commission on such matters as results of radiotherapy in cancer of the uterus became an important source of international information on that disease. Other technical commissions included those on typhus, leprosy, and biological standardization.
Most of the work of the OIHP and the League's health units was cut short by World War II, although the Weekly Epidemiological Record continued. Fear of new postwar epidemics prompted the Allies to draw up plans for action. At its first meeting in 1943, the newly created United Nations Relief and Rehabilitation Administration (UNRRA) put health work among its "primary and fundamental responsibilities."
At its first meeting, in 1946, the UN Economic and Social Council decided to call an international conference to consider the establishment of a single health organization of the UN. The conference met in New York and on 22 July adopted a constitution for the World Health Organization, which would carry on the functions previously performed by the League and the OIHP.
WHO did not come into existence until 7 April 1948, when its constitution was ratified by the required 26 UN member states. In the meantime, UNRRA was dissolved, and a WHO Interim Commission carried out the most indispensable of UNRRA's health functions. The first WHO assembly convened in June 1948.
Among the severe problems that beset the Interim Commission was a cholera epidemic in Egypt in 1947. Three cases were reported on 22 September; by October, 33,000 cases were reported in widely separated areas on both sides of the Red Sea and the Suez Canal. Urgent calls for vaccine were sent out by the Interim Commission within hours after the first three cases were reported, and by means of a history-making cholera airlift, 20 million doses of vaccine were flown to Cairo from the US, the USSR, India, and elsewhere, one-third of them outright gifts. The cholera epidemic claimed 20,472 lives in Egypt by February 1948. During the epidemic the number of countries ratifying WHO's constitution increased by almost 50%.