From 1976 to 1978, David worked as District Child Health Officer in Dhankuta District, Nepal. Later, he moved to the London School of Hygiene and Tropical Medicine, and in 1982, he became Regional Manager for the Save the Children Fund in South Asia, based in the region.
In 1985 he joined the Liverpool School of Medicine as Senior Lecturer in International Community Health. In 1989 he moved to the British Overseas Development Administration (ODA) as a Strategic Adviser for Health and Population in East Africa, based in Nairobi.
Having had a good experience with helping developing countries in the field of medical care, he then took up the post of Chief Health and Population Adviser, at the ODA London Office in 1990, and moved on to become Director of Human Development (as well as Chief Health Adviser) as ODA was transformed to the Department for International Development in 1997.
David joined WHO in January 1999, as Project Manager, Roll Back Malaria, then moved to the Office of the Director-General, as Executive Director, from March 2000. He transferred to the Sustainable Development and Healthy Environments cluster in 2003.
He was appointed Representative of the Director General for Health Action in Crises in July 2003. Since then he has been responsible for taking forward efforts to improve WHO's performance in crisis settings, with an emphasis on preparedness, response and recovery.
David was stationed in the Canal Hotel in Baghdad, Iraq, when it was bombed on the afternoon of August 19, 2003. The blast targeted the United Nations, which had used the hotel as its headquarters in Iraq since 1991.
He coordinated support for health aspects of crisis response operations in Darfur, Sudan, and in countries affected by the 2004 Indian Ocean earthquake and Tsunami.
The United Nations
In September 2005 David was seconded from WHO and appointed Senior United Nations System Coordinator for Avian and Human Influenza by the Secretary-General of the United Nations, to ensure that the United Nations system makes an effective and coordinated contribution to the global effort to control the epidemic of avian influenza (‘bird flu’).
In 1999, David was selected to lead the Roll Back Malaria initiative at the World Health Organization (WHO). Within two years, he was appointed Executive Director and two years later was asked to lead WHO’s Department for Health Action in Crises, coordinating worldwide support for health aspects of crisis preparedness, response and recovery.
In September 2005, David joined the office of the United Nations Secretary-General as Senior Coordinator for Avian and Pandemic Influenza. In January 2009 he was given the additional responsibility of coordinating the United Nations system’s High-Level Task Force on the Global Food Security Crisis.
David works as the Senior UN System Coordinator for Avian and Human Influenza at United Nations Headquarters in New York. He has been seconded to this position from the World Health Organization until the end of September 2007.