1. Direction de la Veille Sanitaire et de la Surveillance Epidémiologique, Ministry of Public Health, Antananarivo, Madagascar.
2. Epidemiology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.
3. Influenza Division, Centers for Disease Control and Prevention, Atlanta, United States of America.
4. National Influenza Centre, Virology Unit, Institut Pasteur de Madagascar, Ambatofotsikely, BP 1274, Antananarivo, Madagascar.
5. Epidemiology and Surveillance Unit, Indian Ocean Commission, Ebène, Mauritius.