Article 24 of the CRC accords to the child the right to the enjoyment of the highest attainable standard of health and to health care services for the treatment of illness and rehabilitation of health, and emphasizes the right of the child to have access to such health care services. The Constitution of the World Health Organisation (WHO) defines health as a state of complete physical, mental and social well-being. Health is therefore not regarded as merely the absence of disease or infirmity. This definition was reaffirmed and expanded in the Declaration of Alma-Alta, which was adopted in 1978 at the International Conference on Primary Health Care by UNICEF and the WHO. According to this Declaration, good health should enable individuals to develop to the maximum of their physical and mental potential, and to live economically and socially productive lives in harmony with the environment, and therefore requires the action of many other social and economic sectors in addition to the health sector.