The World Health Organization (WHO) is a specialized agency of the United Nations (UN) that is concerned with international public health. It was established on 7 April 1948, with headquarters in Geneva, Switzerland and is a member of the United Nations Development Group. Its predecessor, the Health Organization, was an agency of the League of Nations.
The constitution of the World Health Organization had been signed by all 61 countries of the United Nations by 22 July 1946, with the first meeting of the World Health Assembly finishing on 24 July 1948. It incorporated the Office International d’Hygiène Publique and the League of Nations Health Organization. Since its creation, WHO has been responsible for playing a leading role in the eradication of smallpox. Its current priorities include communicable diseases, in particular, HIV/AIDS, malaria and tuberculosis; the mitigation of the effects of non-communicable diseases; sexual and reproductive health, development, and ageing; nutrition, food security and healthy eating; substance abuse; and drive the development of reporting, publications, and networking. WHO is responsible for the World Health Report, a leading international publication on health, the worldwide World Health Survey, and World Health Day.
Its links with the IAEA and distribution of contraception have both proved controversial, as have guidelines on healthy eating and the 2009 flu pandemic.