Medical doctor, specialized in tropical medicine, emergency medicine and epidemiology. In 1989 he went on mission with Médecins sans Frontières for the first time, and undertook long-term missions in Uganda, Somalia and Thailand. He returned to the Paris headquarters in 1994 as a programs director. Between 1996 and 1998, he served as the director of communications, and later as director of operations until May 2000 when he was elected president of the French section of Médecins sans Frontières. He was re-elected in May 2003 and in May 2006. From 2000 to 2008, he was a member of the International Council of MSF and a member of the Board of MSF USA. He is the co-editor of "Medical innovations in humanitarian situations" (MSF, 2009) and Humanitarian Aid, Genocide and Mass Killings: Médecins Sans Frontiéres, The Rwandan Experience, 1982–97 (Manchester University Press, 2017).