Quantitative evaluation on the effectiveness of prevention and control measures against pandemic influenza A (H1N1) in Beijing, 2009 / 中华流行病学杂志

ABSTRACT

Objective To quantitatively evaluate the effectiveness of prevention and control measures against pandemic influenza A (H1N1) in Beijing, 2009 and to provide evidence for developing and adjusting strategies for prevention and control of the disease. Methods Considering the seasonality and the number of vaccination on pandemic influenza A (H1N1) , data regarding pandemic influenza A (H1N1) in Beijing were collected and analyzed. Based on the dynamics of infectious disease transmission, a quantitative model for evaluation of prevention and control measures was developed. Results Both latency and infectious periods of pandemic influenza A (H1N1) were estimated to be 1.82 days and 2.08 days, respectively. The effective reproduction numbers of the three periods were 1.13,1.65 and 0.96, respectively. Thanks to the implementation of a series of measures to prevent and control pandemic influenza A (H1N1), the cumulative number of laboratory-confirmed cases of pandemic influenza A (H1N1) was reduced, making it much smaller than what would have been under the natural situation. Specifically, the program on pandemic (H1N1) 2009 vaccination reduced the cumulative number of laboratory-confirmed cases by 24.08% and postponed the peak time. Conclusion Measures that had been taken during this period, had greatly contributed to the successful prevention and control of pandemic influenza A (H1N1). The 2009 Pandemic (H1N1)vaccination was confirmed to have contributed to the decrease of cumulative number of laboratoryconfirmed cases and postponed the peak arrival time.