Infectious diseases remain the world's leading cause of death.
During the past two decades alone, at least 30 new infectious diseases have appeared. Ebola haemorrhagic fever and Bovine spongiform encephalopathy are prominent examples of newcomers. At the same time, older diseases like diphtheria, cholera and tuberculosis are returning vigorously. In October 1995, WHO established a new programme to combat this growing threat to international public health. Its mission is to strengthen national and international capacity in the surveillance and control of infectious diseases that represent new, emerging, and re-emerging public health problems, including the growing phenomenon of antibiotic resistance.