A space-time criterion for early detection of epidemics of influenza-like-illness
- Cite this article as:
- Toubiana, L. & Flahault, A. Eur J Epidemiol (1998) 14: 465. doi:10.1023/A:1007481929237
Objectives: To develop a method based on a space-time criterion for early detection of epidemics of influenza-like-illness in France. Methods: Since 1984, the French Communicable Diseases computer Network (FCDN) routinely detects epidemics of influenza-like-illness when the national incidence rate is, for 2 consecutive weeks, above a threshold computed by a periodic regression model. It appears that some areas reported early increases in incidence several weeks before the national epidemic. An optimised space-time criterion allows an early detection of the epidemic periods. Results: Applying this space-time criterion to the last 11 epidemics (from 1986), the sensitivity was 0.82 and the specificity was 0.99. Conclusion: This simple procedure can be used as an additional tool for early detection of an epidemic taking into account the distribution of new cases in space and time.