A specialized agency of the United Nations, the World Health Organization (WHO) was founded on April 7, 1948. WHO is chartered to promote technical cooperation for health among nations, to carry out programs to control and eradicate disease, and to improve the quality of human life.

In 1973, the governing World Health Assembly decided that WHO should collaborate with, rather than assist, its member states in developing practical guidelines for national health care systems. As of 1999, WHO had 191 member states.

All countries that are members of the United Nations are eligible to become members of WHO. The World Health Assembly, which meets in May of each year in Geneva, determines the policies of WHO, elects the Director-General, and reviews and approves WHO's budget.

Attempts at international collaboration in the field of public health date back to the mid-19th century. In 1851, the First International Sanitary Conference was...