The 2009 A(H1N1) influenza pandemic in the French Armed Forces: evaluation of three surveillance systems.

Background: The French military forces had to modify their epidemiological surveillance systems at the time of the 2009 A(H1N1) influenza pandemic. The aim of this article was to present an evaluation of the different systems used.

Methods: Two influenza surveillance systems are usually used in the French forces: one permanent (Surveillance épidémiologique des armées or SEA) and one seasonal (Système militaire d'observation de la grippe or SMOG). The pandemic required the implementation of a daily surveillance system (Surveillance quotidienne--SQ), which aimed to monitor disrupted activity owing to 2009 A(H1N1) influenza. The qualitative evaluation of these three systems during the period from September 2009 to February 2010 was performed using 11 criteria based on the list defined by Centers for Disease Control and Prevention of Atlanta.

Results: Although it included only 30 sentinel units vs. 320 for the other systems, the SMOG system was the best-performing system in terms of relevance, feasibility, efficacy, quality of data, usefulness, acceptability, efficiency and cost/benefits/costs ratio. The SQ proved very expensive in terms of logistics.

Conclusion: The SQ did not bring any significant advantage compared with the weekly surveillance schemes. In the eventuality of another similar episode, influenza surveillance could be significantly improved by using the SMOG system extended to more units for better geographical coverage.