Improving the safety of patient care is an issue which affects health systems in both developed and developing countries. To co-ordinate and accelerate improvements in patient safety, the World Health Organization (WHO) has supported the creation of the World Alliance for Patient Safety which was launched in October 2004. The six action areas of the Alliance are Patients for Patient Safety, Taxonomy, Research, Solutions for Patient Safety, Reporting and Learning, and a biennial Global Patient Safety Challenge. The first Challenge covering 2005-2006 was launched in October 2005 under the banner 'Clean Care is Safer Care'. The Challenge addresses health care-associated infection, a major, patient safety problem affecting hundreds of millions of people worldwide.