Key points: - A multidisciplinary surveillance program combines human, equine, avian, and entomological components; - No human or equine cases were reported in 2001 and 2002 in mainland France; - No avian mortality due to VWN was reported, but avian seroconversion was identified in 2001 and 2002 in the Camargue; - Clustered human and equine cases of VWN infection in 2003 in the Var department; - Equine and avian seroconversions (without symptoms) in Guadeloupe in 2002; in Martinique, no viral circulation detected. (R.A.)