ORIGINAL CONTRIBUTIONS |
Large-Scale Comparative Analysis of Pertussis Population Dynamics: Periodicity, Synchrony, and Impact of Vaccination
1 Research Unit 24, "Epidemiology and Prevention," Institute of Research for Development, Montpellier, France
2 "Evolution of Symbiotic Systems" Team, Laboratory of Genetics and Evolution of Infectious Diseases, Mixed Research Unit CNRS/IRD 2724, Montpellier, France
3 Mixed Research Unit 7625, National Center for Scientific Research, Ecole Normale Supérieure, Paris, France
4 GEODES Research Unit, Institute of Research for Development, Bondy, France
Correspondence to Hélène Broutin, Equipe "Evolution des Systèmes Symbiotiques," Génétique et Evolution des Maladies Infectieuses, Unité Mixte de Recherche CNRS/IRD 2724, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France (e-mail: broutin{at}mpl.ird.fr).
Pertussis is a worldwide infectious disease which persists despite massive vaccination campaigns that have gone on for several decades. To obtain an overall view of pertussis dynamics and the impact of vaccination, the authors performed, using the wavelet method, a comparative analysis of pertussis time series in 12 countries to detect and quantify periodicity and synchrony between them. Results showed a clear 3- to 4-year cycle in all countries, but the main finding was that this periodicity was transient. No global pattern in the effect of vaccination on pertussis dynamics was observed, but some spatial synchrony between countries was detected. This large-scale comparative analysis of pertussis dynamics sheds light on the complexity of the multiple interactions involved in global pertussis spatial dynamic patterns. It suggests a need to perform a global survey of human infectious diseases over the long term, which would permit better assessment of the risk of disease outbreaks in the future.
comparative analysis; periodicity; population surveillance; vaccination; wavelet methods; whooping cough