Control of diarrhoeal diseases.

During its early years, WHO was primarily concerned with epidemic control, standardization and quality control of vaccines, and administration of the International Sanitary Regulations. Among the acute enteric infections, cholera received the greatest attention because of its propensity for rapid epidemic spread. When the seventh pandemic of cholera began in 1961, WHO responded with a greatly expanded programme of activities which included cooperation with countries in training and control efforts, and research on treatment and prevention, especially vaccine development. At the same time, numerous training courses were held on enteric infections and a series of controlled field trials established the degree of protection conferred by existing typhoid and paratyphoid vaccines. In 1970, when the cholera pandemic spread to Africa, the emergency assistance programme was reactivated, with increasing attention to the provision of appropriate treatment, especially oral rehydration therapy, rather than the supply of ineffective vaccines. The requirement of cholera vaccination for international travel in the International Health Regulations was abolished in 1973 by the World Health Assembly. Another public health problem of importance during the 1970s was the increase in antibiotic resistance of enteric bacteria, especially Shigella dysenteriae 1 and Salmonella typhi, first in Central America and Mexico and later in Asia. There was a notable acceleration in research on diarrhoeal disease and especially on cholera during this period, with the discovery of several new viral and bacterial agents of diarrhoea, advances in knowledge of intestinal immunity indicating that better protection might be achieved with oral vaccines, and the demonstration of the effectiveness of a single formulation of oral rehydration salts (ORS) in the treatment of all diarrhoeas including cholera.(ABSTRACT TRUNCATED AT 250 WORDS)