[The application of integrated surveillance system for symptoms in surveillance of influenza among children].

Objective: To explore the integrated application of sales of child-specific over-the-counter (OTC) cold related medications in retail pharmacies and healthcare visits of children for influenza-like illness (ILI) in surveillance and early warning of influenza among children.

Methods: An integrated surveillance system (ISS) was implemented since 2012 in Qianjiang County, a rural area in Hubei Province of China. The daily information from August 1, 2012 to February 28, 2013 of health care visits of children for ILI reported by 80 health facilities and sales of 14 child-specific over-the-counter (OTC) cold related medications reported by 11 pharmacies were extracted from ISS database. Cumulative sums (CUSUM) model was conducted to analyze the degree of fitting and the early warning signal generated; the correlationship was then analyzed further.

Results: In 212 days, 983 visits of children for ILI and 12 819 sales by person of child-specific OTC were reported. Conducting CUSUM model, the fitting degree was in the acceptable range, 31 warning signals were generated from ILI data series with 3 peak periods and 14 from OTC data series with 2 peak periods. A similar time trend of two data series was observed with a correlation(r = 0.497, P < 0.05), but without any spatial clustering. And the optimal correlation(r = 0.505, P < 0.05) appeared at a time offset of 4 days preceded by OTC sales.

Conclusion: The availability of integrated surveillance system for symptoms could be applied for surveillance of influenza among children; while it could explore the possibility of real epidemic in the very early stage.