1186. Estimation of the Reproduction Number of Pandemic Influenza A(H1N1) 2009 from Antiviral Agent Consumption
Session: Poster Abstract Session: New Approaches to Anti-Viral Therapy
Saturday, October 22, 2011
Room: Poster Hall B1
  • DH_Lee.pdf (431.8 kB)
  • Background:  Novel Influenza A(H1N1) was detected in 2009. Many studies were performed to estimate the reproduction number of Influenza A(H1N1) 2009. However, most of these studies were focused on confirmed cases in the early pandemic phase. The Korea CDC provided the antiviral agents to acute febrile respiratory illness patients without confirmation diagnosis. All pharmacies and designated hospitals reported their daily consumption of the antiviral agents to the Korea CDC through internet antiviral agent management program. The purpose of this study was to estimate the reproductive number of pandemic influenza A(H1N1) 2009 using the data of antiviral agent prescription data in Korea in the period of the highest pandemic activity.

    Methods:  The study subjects were the patients who were prescribed national stockpiled antiviral agents from August 21, 2009 to April 30, 2010. In this study, two different approaches were used to estimate the reproduction number. The first method was estimation based on cumulative number of cases, that was simple deterministic approach. It was derived from the growth rate in exponential distribution. The second method was real-time estimation of the time-dependent reproduction number, Rt.

    Results:  About 3,123 thousands of people (6.27% of total population) were prescribed the antiviral agents. The antiviral agent prescription rate was higher in children and adolescents(3-19 years) than other groups. Also the rate was higher in urban area than rural area. Antiviral agent prescription increased late in October, peaked on October 30, and decreased from mid-November. Using simple deterministic approach, the reproduction number was estimated to be 1.45(mean generation interval, Tc=1.91), 1.59(Tc=2.5) and 1.71(Tc=3) for the period October 16-30 (From 3rd Friday to 5th Friday of October).

    Conclusion: The reproduction number estimated from antiviral agent consumption was similar to those from previous studies. In addition, the antiviral agent consumption was higher in child and adolescent and in urban area.

    Subject Category: V. Virology including clinical and basic studies of viral infections, including hepatitis

    Dong Han Lee, MD, MPH.1, Dae Young Kang, PhD2, Chang Soo Kim, MD, PhD2, Jeehyun Lee, PhD2, Woo Joo Kim, MD3, Min-Sun Song, PhD4, Sang Sook Shin5, Byung Guk Yang, MD, PhD5, Byung Yool Jun, MD, PhD5, Jong Koo Lee, MD, PhD5 and Il Suh, MD, PhD2, (1)Division of Public Health Crisis Response, Korea Centers for Disease Control and Prevention, Cheongwon gun, South Korea, (2)Yonsei University, Seoul, South Korea, (3)Korea University, Seoul, South Korea, (4)Dongshin University, Naju, South Korea, (5)Korea Centers for Disease Control and Prevention, Cheongwon gun, South Korea


    D. H. Lee, None

    D. Y. Kang, None

    C. S. Kim, None

    J. Lee, None

    W. J. Kim, None

    M. S. Song, None

    S. S. Shin, None

    B. G. Yang, None

    B. Y. Jun, None

    J. K. Lee, None

    I. Suh, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.